Would be interested in any findings as to what the dreaded SWD fruit fly did this year.
Would specifically like to know if anyone found them in their plums. We in Seattle hardly had enough plums this year to make a survey of the problem.
What I DID find was some larvae in both my blackberries and local salmonberries .....and I presume this was from the spotted wing drosophilia.
What we did find was some sour cherries were attacked by this more vicious fly.
What we did NOT find was any sort of regularity or predictability....it appears to be a fickle pest attacking different crops at different times.....but I would like to know of anyone else's results here in the NW....thanks 
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I did not see any SWD damage in my apples, currents, or blueberries this year. I did spot a male SWD in my kitchen just a couple of days ago! It was hanging with the normal fruit flies about the compost pail. The spots on the wings were clear as day. Makes me wonder if I am going to need to take any measures with my composting processes. I am thinking of hanging some sticky traps under my covered composters lids to gauge their presence.
Dan
I just attended a Seattle Tree Fruit meeting....Shaun Shepherd was there from HOS to identify fruits. Thank you, HOS, for sending up your ID specialists!
Also there today was Dr. Beverly S. Gerdeman who has been studying the Spotted Wing Drosophilia. She noted that there is indeed some strange behaviors.....it is too early to tell but the fears of this fly having 8 or 9 generations here in the Pacific northwest appear to be unfounded.....it is much less than that but we can not tell from just this season because this past summer and spring was unusually wet....maybe only 3 or 4 generations and not all of those generations are very lethal.
What she also noted were:
1. SWDs were caught in traps near May 25 but not actually doing damage until July 25.
2. The raspberry, particularly the red raspberry was hard hit by SWDs in the Mt. Vernon Washington area.
3. Plums....some saw damage and some did not.
4. Blueberries....some saw damage late in the season but not early in the season.
5. Strawberries were not hard hit in many sections (although some people saw damage).
6. The bug appears to "make decisons" (anthropomorphic) about which crop in close proximity will be attacked and which will be left alone.
I am sure I misquoted her, but I also think I am in the ballpark.... more to come on the WSU NWREC website in the future....where more exact info will be forthcoming.
I am a long-time reader of posts at this forum but I thought it was time to relate my experience this summer with SWD. I have a small backyard in SE Portland. At the end of June, I picked a raspberry which practically fell apart in my fingers and I suspected SWD. As I inspected the interior of the berry, I could see a mushy interior and a white larva. Over the next few days, i found more evidence (mushy interiors and white larvae) in more berries. I was concerned that the population could get out of hand very quickly. I looked at the OSU website and various links and decided to sacrifice the summer bearing canes in the hopes of reducing subsequent generations. I froze any berries with color to kill any larvae and eggs and disposed of the berries in the garbage disposal. Since the compost pile attracted fruit flies, I stopped composting fruit and vegetable waste and turned the compost pile to bury the recent items. I will outline what I did to protect the remainder of my fruit.
1) I removed white alpine strawberry plants which had gotten a bit rampant in my yard. I saw a couple of fruit flies hovering around one berry so they were attracted to the berries.
2) Small blueberry plants (Duke, Bluecrop, Elliot): I constructed tents over each one using no-see-um fiberglass window screen and Agribon (AG-19). To seal the "seams", I used clothespins along the vertical ones and bricks at the bottom. Going under the tent to pick blueberries was definitely a disadvantage but I did not any signs of SWD in the fruit.
3) Young Q1-3 peach tree: earlier in the season, I had already covered the fruit with footies + Surround to protect against other "bugs" so I hoped they would be protected from SWD as well. By the time they were ripening, I don't know how many fruit flies were in the vicinity but I picked undamaged fruit.
4) Sweetheart cherry tree: This young tree only had 15-20 cherries so I tried both footies and plastic baggies. I did not detect any damage though there may not have been enough cherries to attract the flies. Footies are not practical for cherries, though!
5) Thornless Blackberry: One young plant with 2 canes. I had communicated with Dr. Vaughn Walton at OSU who suggested that paint strainer bags might be useful to protect cane berries. Based on two bags I had purchased, I designed smaller bags from no-see-um netting material to use over berries. However, due to time constraints, I was not able to make bags fast enough to cover all berries. After finding evidence of some "bad berries", I cut off the ones that were unprotected. I harvested some "good berries" from the bagged ones, so I was encouraged by my mini-experiment. Protecting a huge bush would be daunting, though. Ironically, the only time I saw a male SWD (the spots on the wings were very evident) was after it landed on a freshly harvested berry.
6) Apples (GoldRush and Rubinette) and multi-grafted Asian Pear tree: At thinning time, I had already covered the young fruit using either footie + Surround or plastic baggies. I had seen mixed reports about whether SWD would be attracted to this fruit. In the end, I ended up worrying more about a larger creature that managed to pull off and consume some fruit.
7) Fall raspberries (Heritage and Amity): The berries were ripening by early September and I used my homemade bags to protect berries after they were pollinated. Admittedly, it was somewhat of a challenge to keep up with the bagging. Berries are difficult b/c they are not all pollinated at the same time and the bunches of berries are different sizes. My canes are not particularily dense but I had a hard time keeping up with the bagging and I was still trying to make bags as fast as I needed them. The beginning of the fall season started out with no signs of damage by the fly. However, as time went on, I began to see evidence of SWD. As before, as I found berries with larvae, I froze them before disposal. However, I was able to harvest a larger number of undamaged berries than damaged berries so I think the bags can help. However, this fall, I will cut the Heritage canes to the ground to avoid the canes next summer. I will test the bags on the Amity summer canes. From what I have read, I think the commercial growers were able to protect their crops with more frequent sprayings though I don't know what is available to the homeowner. It used to be that raspberries were my easiest crop to grow!
I will add that I saw evidence of SWD in other raspberry patches within 5 blocks of my home. I wonder how many people had damage from SWD but did not notice it.
I tried to keep this brief but there was a lot of information I wanted to convey. Feel free to ask for more clarifications.
OK we all need to be careful when posting information, SWD is a very specific drosophilia. From larvae how was this pest identified? most drosophilia need to be in adult form for accurate identification, this is why the extension offices released information on how to ID this fly.
there are 1,000 s of fruit flies out there and this is how misinformation is spread. One pest gets on the alert list and then gets all of the blame, causing roomers and misinformation.
All of the above creates fear which intern leads to inappropriate pesticide use.
thank you for listening to me and my 2 cents worth
Randy ac7nj@arrl.net
Yamhill County Master Gardener
Let's keep sharing information and strategies and see what seems to work best. I am aiming for organic strategies and it seems to work well so far, but creativity seems to come from our innovations off of others' strategies. Good work guys, let's figure out good ways to get good fruit and keep the bugs out.
John S
PDX OR
thanks "redberry: for your feedback....I will print off your comments and read them to consider.
Now, as to the point made by "ac7nj" let me respond: It is definitely possible there was some mis-identification from my part as I not only was NOT checking the more easily identifiable adult form but I wasn't even checking with anyone or anything on the larvae I observed......so there IS a possibility that I mis-identified SWD on my property for the wild Himalayan blackberries and in my neighborhood for the salmonberries....this is quite possible......and just because I have never noticed larvae in blackberries or salmonberries before this year does NOT mean they have not been there before......all I can say is that this is the first time I noticed them....and it is only an ASSUMPTION on my part that this was the SWD....I could be wrong.....but I have never even heard of larvaes swimming in these wild blackberries before and I at one time used to pick them and sell them in Eugene, Oregon. I would like to know if there is new knowledge about this out there.
The other observations that I made with regards to compost piles, sour cherries, plums, and especially the red raspberries (and strawberries) are, however, more in the realm of prove-able science as these come from the observations of people in the Seattle area like the Tilburys, Lori B., and most importantly, Dr. Bev Gerdeman........and these people were indeed going to the trouble of fly identification.
No doubt, the fears of this pest have already been classically overblown and it is not as bad as feared.....sometimes the fears of pesticide use are also overblown (I believe).....but the more knowledge we can share the more intelligently we can solve the problem and not just blast the environment with pesticides....so we agree completely on that and thanks for letting me clarify as I don't wish to mis-represent my knowledge.....often I write to be interesting and not to be technically correct and this can be a problem. Sorry.
Hopefully, everyone here will post again as we work these things out.
Don, et. al.:
This damn things were an horrible problem for me this year.
I am just starting fruit trees so this invasive Asian Fruit fly did not present any sort of problem for the fruit trees I am starting. I live on rural property in southern Marion County. I was able to get some early salmon berry and because of the problems I have attempting to get rid of invasive blackberry, I no longer consider blackberries an enjoyable edible food so I cannot comment about these fruits.
My problems were two-fold. The first related to storing/accumulating fruits (some of which I purchased) prior to processing. If I did not IMMEDIATELY get to work on whatever was at hand, the flies seemingly attacked the produce en masse. The concept of keeping a bowl of fresh fruit on the counter for snacking or to slice with breakfast granola became fundamentally impossible. In the past, I would keep boxes of peaches and plums unrefrigerated for 7-10 days as long as the box was covered with an excluding towel. This was no longer possible -- whether because the fruits were already infested or because of the severity of the in situ attack.
Secondly, if any fruit growing in the garden was in any way damaged, the flies would attack it. Last year, I enjoyed some twenty canteloupe -- this year I ate TWO. Any melon approaching ripeness was infested with both flies and worms (as well as slugs and god knows what else). If a tomato split (as with the rains of mid-September), the flies would get into the rupture; and while I found no maggots present, it seemed that the flies somehow innoculated these damaged fruits such that they became almost instantly moldy. Ditto for all but the most piquant peppers. Some grapes were wormy but mostly those clusters were more seriously moldy. If there were any break in the skin of the butternut squash I grew, the flies would be at it, and again no worms were present, but mold and severe rot destroyed these items within a couple of days. Additionally, they got into my pickle crock (God only knows how) and ruined everything therein.
My compost pile became a swarming mess -- turning it seemed to make little or no difference. This compost pile may be a perpetual problem as I killed a male fly this evening while I was preparing supper (and this subsequent to the sub-freezing temperatures of the last several days). At this point in time, I do not see how I will be able to continue to compost process waste (making disposal a real and serious problem as I really do not want all of this additional stuff going into my septic tank).
I have set out multiple traps of yeast and sugared water that traps tens and tens of flies without any serious dimunation of these pests. And I really wonder what type of realistic control might be possible next year. Beyond the ubiquitous invasive blackberry that can serve as host, I have numerous native wild cherry (P. emarginata), Oso plum, Oregon grape and salal -- the latter species which I am attempting to encourage for the benefit of native wildlife but seemingly are likely hosts. If these are, in fact, host plants, how will wildlife be impacted???
I have planted approximately 30 fruit trees, a dozen blueberry bushes and have 140 feet of established grape arbor. I was planning to put in 40 feet of kiwi arbor. Footies are a fundamental impossiblity for fifteen apple trees and wholly unrealistic for plums. The undisputable reality is that no-spray or an organic garden/orchard is likely to become impossible as I see no means to either control or get rid of this menace. Whether I attempt to grow items myself or purchase from area growers, it is almost a 100% certainty that these foods that I will eat will have increased residuals of more bio-toxic agricultural pesticides.
And this SWD acronym is bull$%*#, likely to become as meaningless as the similar acronym 'WMD'. I think we ought to be calling them what they actually are -- an invasive Asian Fruit fly (as with the Med Fly) even though, in actuality they are a WMD and quite realistically a purposeful bio-terrorism weapon. Maybe somebody from the right-wing lunatic fringe can mouth platitudes vis a vis this plague to convince me it is one of the positive benefits of "free trade". It is likely to be as meaningless as any solution eminating from academics or government officials when these types finally get around to proposing some control method after several decades of study.
Suffice it to say, I am really upset because these damn things were a real problem for me this year and I expect that next year will be much worse.
Hey Lee,
I'm sorry to hear about the affect of the fly on your plants this year. This is the nightmare scenario people have been talking about. I think it will be really interesting to see how people can adapt to this pest and avoid things getting worse.
I am optimistic, however. I think that we are probably going to see a large increase in the types of insects that would eat these tiny flies. I also think that people will observe things and make experiments that combine to be quite effective. I don't think we know what all of them are yet. Some that have shown promise so far are the tulle (wedding veil cloth) and clay kaolin spray. I think it is crucial for us to share ideas that have worked so far. Another that I have experimented with and shows some promise is the micro-perforated bread bags for hot bread.
I am not willing to give up on organic solutions. The taste, nutrition and health of the soil is just too different. I haven't had many problems yet. I do think that over time, we will find ways to manage this problem, but it may be a rough time until we adjust to it.
John S
PDX OR
I am uncertain how we will adapt. Stuart Olson was the individual quoted in a recent Oregonian front page article regarding the effect of this invasive Asian Fruit Fly on his peach orchard (Olson’s Orchard – Hwy 22 east of Salem at the Joseph Exit [#5]). He lost his entire late crop of peaches in ‘09; his approach this year was a significant increase in the application of pesticides over a shorter interval. The tech info I have seen, in some instances, recommends the use of Malthion (YIKES ! ! !) This is obviously not an organic approach. His orchard is about six miles west (upwind) of me as the fly flies.
I don’t see how this invasive pest will be controlled (let alone eradicated). If native bitter cherry is a host/vector, the flies will have a huge launch pad from which to attack all later ripening crops and fruits. Depending on the site on my property, these emarginata cherries ripen before sweet cherries come to market. If the flies then subsequently use the invasive blackberries as their next host/vector, by the time plums, peaches, nectarines, grapes and figs begin to ripen, their numbers could be at truly horrific proportions.
And just to add another note of absurdity, governmental agencies (as Marion County Weed Control) no longer even attempts to eradicate invasive blackberry anymore. At a presentation I attended several years ago, the department head indicated that blackberry was becoming resistant to single herbicide applications so that Round-up was no longer effective alone and it was necessary to be used in conjunction with Crossbow.
You are optimistic that natural preditors will increase – if the first response is increased use of herbicides (eg Stuart Olson) then other insect preditor numbers are likely to be reduced as well. The following information downloaded from a BC website (http://www.agf.gov.bc.ca/cropprot/swd.htm) is not positive:
Spotted wing drosophila overwinters as adult flies. In spring flies become active, mate and lay eggs in suitable fruit. Based on climate model predictions, there could be up to 5 generations per year in B.C. Generations will likely be overlapping as flies are relatively long-lived particularly at temperatures 20oC and cooler. Based on a Japanese publication (Kanzawa 1939), oviposition lasts 10-59 days, with 7-16 eggs laid per day, and averaging 384 eggs per female. Eggs hatch in 2-72 hours, larvae mature in 3-13 days, and pupae reside in fruit or outside of fruit for 3-15 days. In the lab at constant temperature, one generation takes 21-25 days at 15oC, 50 days at 12oC, 19 days at 18oC, 8.5 days at 25oC, and 7 days at 28oC. Adults are attracted to dropped and decaying fruit and will feed on it.
None of the publications I have perused even mention potential natural preditors.
You do raise an issue that is of particular interest to me and that relates to sharing information. It is my hope that HOS will take it a step further and proactively initiate planned and controlled research and then subsequentlypublish these results. For example a contributor to a past thread indicated that he was going to loose chickens in his orchard as a means of controlling either coddling moth or apple maggot (sorry I forgot which one). If poultry feed on larva in windfall or with their scratching/foraging techniques, they might be a very effective means of control. If HOS could coordinate a group of participating members in a controlled study (comparing over time trap numbers and fruit damage with or without poultry) I think that the information would be both valid and useful. There was also a previous discussion concerning the use of pear extracts/esters as a potential bait for coddling moth but at a cost of $150 per ounce, was beyond the price range of most HOS members. However, if that ounce was slightly diluted and divided-up and distribured to ten or more participants (each paying a proportional amount for the extract they receive) and then filling out some standardized reporting form, important information could be generated. The key however is standardizing the process and having someone capable of planning; and then doing the statistical analysis and write-up.
However of immediate concern to me is an effective compost pile management approach so that it will not be an overwintering site for this damned invasive Asian Fruit Fly.
Lee, I’ve not had the time as of late to pay near as close of attention to my orchard and fruit as years past… Thanks for letting me know what’s up with this Asian Fruit Fly – its best we’re aware of both the good and bad as we to plan to build and maintain our dream orchards. I also appreciate your straightforward descriptions and find them a refreshing departure from the typical BS of our commercial society. I’m also sickly disappointed to hear such a devastating report from your orchard and garden, especially after all you’ve put out. So, is it better to have loved and lost than never loved and never lost..?
Maybe we’ll simply scale back our ventures to ‘what works,’ keeping in mind last year was a very …crappy season. Glad I’ve enough going on fruit wise that I can see what survives and what doesn’t, but I’ve often wondered if it would be appropriate among this organization to list and describe all the ‘stuff’ I’ve given up on..? I’m now to the point of wondering if ‘replacing’ is worthwhile. I did expand my garden plot/s in a big way this year; with a 25 year old trellis of seedless grapes the losers. And I can very much relate to your war on and hatred of Himalayan Blackberries. I was once scolded around here for attempting to spread the rust (around home) that was supposedly going to devastate them three or four years ago … as I spent days fighting them on a neighbors place last summer.
-- If nothing else, let me know what the little …flies don’t destroy – fortunately, along with all the fruit I could eat, I was trained from youth to 'clean my plate,' eventually learning to ‘like’ about anything – so there must be something left 
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Thanks LeeN for posting your experience which was far worse than my experience. Did you report your experience to anyone at OSU?
When I found the first berry with the larvae, I did not want to jump to the conclusion that it was SWD. I thought they'd be more of a problem in areas with more crops. However, based on information at the OSU website, it appears that homeowner sites were "hotspots" for SWD. In my case, I saw small clusters of fruit flies around ripening berries and I have never seen fruit flies around the plants. I also saw a male SWD fly (obvious with its spotted wings) so they were definitely in the vicinity. I have two dead female fruit flies which I tried to ID using a microscope but I was unable to find the ovipositor to make a positive ID. The larvae and mushy fruit was also consistent with descriptions for SWD damage.
I think LeeN's second post brought up additional valid points. In my communication with Dr. V. Walton, he stated that "eradication will be difficult, suppression/management is best...". As LeeN mentioned, compost piles are a big attractant for fruit flies and I am rethinking how/what I will be composting in the future. Dr. Walton said that larvae can be killed in compost at high enough temperatures though he did not indicate the temperature needed. (Other sources said that composting was not effective.) Since I did not want to put banana peels down the disposal, I buried them in my mostly finished compost. This seemed to prevent attracting fruit flies of any kind but it definitely meant I could not just throw stuff on the pile. The OSU website recommends burying vegetable/fruit waste but that is not always practical if you don't have the space. I, too, have wondered about native plants like Oregon grape or salal that can act as hosts. I have them in my front yard and they are common plants for landscaping around businesses. At my place of employment, they have blueberry bushes and I noticed larvae in the berries late in the season. When I informed one grounds crew member of the larvae, he was unaware of SWD. Basically, my point is that it will be impossible to protect or eliminate all hosts and people will unknowingly provide hosts for the fly.
As for control, I, too, wondered about natural predators. I did my best not to disturb spider webs but I can't say I ever saw any flies in the webs. I am aiming for a no spray approach but bagging/netting fruit is definitely a trade-off between time/effort/cost vs. harvest. Certainly, a large grower will not be able to bag everything especially something like berries. Ideally, someone can figure out a trap that will attract the flies before they lay eggs since it is the egg-laying and larvae development of the life cycle that destroys the fruit or another possibility is something that repels the fly.
(Viron: Before I say anything else, I want to express my very personal thank you for your many, many contributions to this website and to the HOS. You are very obviously dedicated, intelligent, informative and honest; and the information you convey is very helpful.)
I am truly at a loss as to how to deal with this Asian Fruit Fly invasive menace. Yes it was an absolute crappy year for gardening (in my view the early/first symptoms/manifestations of global climate changes). Given what I have been reading on-line regarding Drosophila suzukii, the problems I experienced this year are minor compared to what we are likely to experience in the very near future. The observations of Redberry and Redberry’s suggestions are excellent; but they also are indicative of the already endemic spread of this menace.
Fundamentally, the more I research and read regarding this invading peril, the greater are my concerns that we have an absolutely uncontrollable problem that will endanger (and quite possibly undermine) home gardening and all orchards in our area. Both Redberry and John S are hopeful of natural predators. I have found nothing discussing this subject. And to this end, I have sent a message to Portland Audubon asking for their suggestions vis a vis bird species such that I could build and install suitable nesting boxes. When I receive a response I will post it.
I am less than hopeful that our feathered friends will provide a realistic solution. I also like and value spiders but even Shelob herself would be overwhelmed. This is because of what I have read at the following website entitled “Use of Pesticides to Control Spotted Wing Drosophila - Strawberries and Caneberries - ANR Blogs ( [url:133ya55g]http://ucanr.org/blogs/blogcore/postdetail.cfm?postnum=1704&[/url:133ya55g] ). Following is a quote from that site:
“Resistance: With such outstanding results as those above, it is easy to decide that one will go with one of the cheaper chemistries and continue until the flies are all gone. While this sentiment is understandable, it is imperative that pesticide users rotate the chemicals they are applying. Since one is pitting the chemical against what is quite likely several million flies per acre and the subsequent genetic diversity such a large number offers, the likelihood of the pest population becoming resistant and not controllable after continued use of the same chemical application after application is very high. History with other pests tells us that it can take only a few years to reach complete resistance. Rotate."
The chemicals being ‘recommended are the organophospate Malthion and the synthetic pyrethroid Mustang. Both are apparently broad spectrum (thereby affecting bees and other good bugs, while the latter is nasty to fish and aquatic organisms). Despite the warning, I fully expect the misuse of these and cheaper chemistries. While use of these pesticides are worrisome, two other issues raised in this above paragraph are terrifying (to me).
The first is “. . . quite likely several million flies per acre . . .â€. I did a little math. From a single fertile female that is capable of producing 300 eggs with an assumed 50% survival rate, her second generation could produce 75 fertile females (300 divided in half to remove male numbers divided again by two to account for a 50% survival rate) which if they reproduce at the same rate will produce a third generation of 1406 fertile females (75 times 75 divided by 4 [removal of males and 50% survival]. The fourth generation of uncontrolled reproduction is 1406 times 1406 which equals 1,976,836 flies. Since nobody is mentioning natural predators, a 50% survival rate may be either entirely realistic or maybe too low.
Secondly, there is the remainder of the sentence and the next: “. . . the subsequent genetic diversity such a large number offers, the likelihood of the pest population becoming resistant and not controllable after continued use of the same chemical application is very high. History with other pests tells us that it can take only a few years to reach complete resistance.â€. Given those reproductive numbers, I sincerely doubt that the rotation of only two chemicals will circumvent the issue of genetic diversity vis a vis resistance.
It may be that “based on information at the OSU website, it appears that homeowner sites were "hotspots" for SWD†(which sounds to me like ‘blaming the victim’). The academics must also include as “hotspots†every “wild†fruit tree on some abandoned site, all the native species (Bitter cherry, Oso plum, etc), and the thousands and thousands of acres overrun with invasive blackberry. I would like to point out that every dumpster behind every grocery store and restaurant are also equally problematic “hotspotsâ€; as well as the garbage cans of anyone disposing of fruit and vegetable wastes. And to all of these “hotspots†one can add landfills and refuse transfer sites. I consider it extremely significant that Olson’s Orchard is about one mile downwind from the Marion County Transfer Station located east of Salem off Hwy 22.
I have zero faith that OSU Extension Service or any other governmental entity will present ANY realistic answer; and the solutions they will recommend will be just that – poisonous chemical solutions with adverse consequences to anyone and anything that comes in contact with them as they are spread into the air, onto the soils of our watersheds, into our rivers and streams, and into our ground waters (and thus further disrupting the overall natural ecological balance). I have studied the Extension Service “Insect Management Handbook†enough to know that the control recommendations therein are not “organic†. An ounce of prevention may be better than a pound of cure; but selling the tons and tons of “cure†is a hell of a lot more profitable than selling an ounce of prevention. Besides, for multi-national corporations, their short-term profits are increased when they avoid the costs of the ounce of prevention.
This invasive Asian Fruit Fly (Spotted Wing Drosophila [Drosophila suzukii]) is not just a problem, it is an ecological catastrophe. I fully expect that next year will be worse than this year.
Well, everyone comes to the forum with a different perspective.....personally, one of the "hats" I have worn in my life was once having been a Health Inspector and I do not share the fear of pesticides that many here in Seattle and Portland have......would it be good to protect the fruit with as few insecticides as possible and as organically as possible?....sure, but I lose zero sleep worrying about what is on the fruit in the supermarket.....I have also picked tons and tons of fruit in Eastern Washington and ate directly off the tree while I did.
My concerns with SWD is that it is a bug that can effectively "symbolize" what it is that we worry about......how the bugs are getting smarter and smarter and the restrictions for pesticides are getting tougher and tougher and the result is indeed that it is becoming next to impossible for the backyard grower to do anything but maybe reconcile himself to eating the larvae in the fruit......and, frankly, maybe we should be doing that.
Some silver linings behind these clouds of smart bugs "bugging" us are these, though:
1. GF 120 Naturalyte Cherry Fruit Fly Bait will apparently work for SWD, apple maggot, and cherry fruit flies. Will the flies "adapt" at some point and make this specialized Spinosad organic eventually ineffective? Sure, but at least something appears to work right now (from what I have heard...because I have not bought this product but can tell people where they can....it is expensive and requires a minimum 1 gallon purchase.....am relatively confidant on this one).
2. I believe, that given time, genetically resistant strains will be developed for fruit and things like mating disruptors will develope.....the bugs get smarter and so does science.....it would not surprise me if some tricky new thing comes up for the Drosophilia fly......some time in the future if we had the patience.
3. However, I have become convinced that urban dwellers need to think about mosquito netting over potted fruit trees. This will work.....it's not 100% natural, but at least something works....and who wants to see all the pesticide-using big farms in California and Eastern Washington supply all the fruit? Small fruit trees and bushes, completely protected after pollination by a mosquito net, can work.....I suggest this as as a solution because I see it getting harder and harder for the urban dweller to protect his fruit.
4. Bags and foot sox also work for big trees and individual fruit.....we know this works for apple maggot fly and I suspect it works for drosophilia (but all the data is not in).
5. At the Piper Orchard in Seattle we have very few codling moths and we apply ZERO pesticides......so, it seems believeable that the City Forest surrounding it is indeed supplying birds and what not that are reducing the codling moth population. This, too, is a silver lining.
http://www.piperorchard.org
6. At a farm I worked on at Vashon Island, they had ZERO apple maggot problem.....Why? Well, the deer come in every night and eat every single apple that has dropped to the ground. That kind of sanitation may have had something to do with it......apple maggots don't exit the apple until the apple has dropped. In certain situations, chickens will work, but not where the neighbors don't have chickens and are not protecting their fruit trees as well.
7. Personally I am curious to see what a harsh winter would do....these larvae are right below the surface of the ground right now......no, I don't expect them to die.....all I am saying is that a "wait and see" approach has something to be said for it. I am almost hoping for some unusually cold weather, like we had a week ago this winter.
There are answers.....there are even organic answers....and I hope I don't sound "Pollyanish" because realistically I also see where it is just becoming a little more work all the time every year......in my opinion and all.....and we can all confess to some frustration.
DonRicks (aka Pollyanna):
Somehow, we are living in two separate and distinct realities.
RE: "I do not share the fear of pesticides that many here in Seattle and Portland have......"
I surmise from your statement that your primary concern vis a vis pesticides relates to the food you yourself consume. Beyond that personal concern I have for myself relative to the foods I ingest, my fears of pesticides also considers the occupational expossure of these chemicals to agricultural workers. I also consider the impact of these toxic chemicals on all the other non-target species (including bees, ladybugs, birds, fish, amphibians, reptiles and mammals). These chemicals do not magically disappear but persist in the environment for often extended periods of time. How these persistant chemicals interact with other chemicals (both natural and artificial [thousands and thousands of residential, agricultural and industrial]) and their intermediated breakdown constituents is completely unknown and worrisome. Before the BP mess in the Gulf of Mexico, there was a "dead-zone" off the Mississippi delta the size of the state of Connecticut attributed to agricultural run-off and industrial pollutants. Another "dead-zone" is now regularly occurring off the Oregon coast.
RE: "......how the bugs are getting smarter and smarter"
Genetic adaptability (EVOLUTION) is a fact despite the rantings of the Biblical literalists. The bugs aren't getting smarter; we (or at least a significant part of humanity) are simply becoming dumber (DE-evolution quite likely to the point of our own extinction). People are willing to delude themselves that global free trade is some great and wonderful idea without any negative consequences. Thus we introduce yet another extremely destructive species into a new enviroment where none of its natural predators exist. As a wood technologist, I am all to aware of the virtual extinction of the American chestnut (Castanea dentata); and grew up during and witnessed the cataclysm of the demise of the American elm (Ulmus americana). Both attributable to the ignorance and arrogance of humanity's willingness to introduce apparently anything and everything into local ecosystems.
RE: I believe, that given time, genetically resistant strains will be developed for fruit and things like mating disruptors will develope .....the bugs get smarter and so does science ...... some time in the future if we had the patience.
The wholly disheartening implication is that we can chuck-out all the existing genetic diversity of heirloom varieties (for all of the multiple species this damned invasive pest will affect) and substitute (in the future if we wait long enough) some singular "miracle" of modern science. Assuming, of course, that the genetic adaptability of the pest co-incidently ceases to exist. And in the interim period, what are those individuals who depend on the crops of existing species for food (consumers and home gardeners) and livelihood (farmers and distrubutors) to do? I find your suggestion to eat worms insulting and offensive. It seems that all of us have an infinite supply of money such that the newly imposed additional costs for dealing with menace are of no consequence; and that the additional work and time requirements therein associated are likewise inconsequential.
RE: At a farm I worked on at Vashon Island, they had ZERO apple maggot problem.....Why? Well, the deer come in every night and eat every single apple that has dropped to the ground.
This sounds like a 'Disney'esque Bambi fantasy wholly at odds with my experience. Apparently you have never witnessed deer standing up on their hind legs and literally stripping a tree of its fruit and foliage (during summer drought periods) as high as they could thus stretch. On my rural property, growing smaller fruit trees is fundamentally impossible because of the destructive predation by deer. And I attempt to utilize windfall for sauce, drying, pies and, hopefully in the future when I build a press, cider, perry, etc.
RE: I am curious to see what a harsh winter would do....
In perusing the internet regarding Drosophila suzukii, I found information dealing with this menace in Michigan -- a place with considerably more severe winter weather than exists in our region.
In my above response, I have purposely attempted to be neither personal insulting nor demeaning to you . . . . I just cannot understand how you could be so blithely unaware or insensitive. Maybe you are correct -- that it is entirely related to "a different perspective". But in attempting to comprehend your statements, I am again reminded of/recollect Whitehead's Fallacy of Misplaced Concreteness.
If I have offended, I sincerely apologize.
Well, yes, Lee, there are different perspectives.....we could also go the rounds on what are the facts surrounding the current ideas about global warming....or global climate change being even more the current rage.....and in what context to put those facts......
This forum makes for interesting discussion as long as we can be civil about it.....but unfortunately, when we insult the intelligence of others we make it difficult for people to come up with the most cogent arguments or facts....the religious "flat earth" people are maligned but what of the religions of those who hate the religious and of the sciences that they subscribe to? Sometimes those who stand behind science are not really truly scientific.
One of the interesting things about such a seemingly harmless topic as gardening is that if you scratch below the surface you can find very stronly held beliefs on some of these topics and those feelings can come to the surface when we talk about genetic modification, pesticides, etc.
But let me get to something we both agree on. You mentioned that you thought it would be great if the Home Orchard Society did some experimenting on things like chickens reducing our apple maggot problem or some such.....and I agree with you. We know that chickens do scratch below the surface and eat the larvae. We know this can work. We also know that it is problematic to correct the problem as long as you live in an urban setting where the neighbor has trees that are infected with apple maggot. You might be clean from the bug, but it does no good if your neighbor is not.....(and I am not sure we should legislate against him)
I am well aware of the problem of deer in orchards. When I pruned this orchard on Vashon Island I lamented how the deer were destroying my work from about 5 feet on down...so, at first I did not like the deer.....but when I saw the apples did not have apple maggot at the end of the season, I began to re-love my "deer" friends again....realizing they were possibly a blessing.
I mentioned the deer as a confirmation of this idea of the chickens helping to sanitize the orchard and also suggested the deer as a confirmation of this.....no, as a general rule you do not want deer in the orchard.
I agree it would be GREAT to dialogue about ideas, to even have differences of opinion, and to see what others find.....and to admit that maybe some of our pre-conceived ideas are wrong....on both sides of the deer fence, so to speak. The experiments, findings, and arguments of HOS people could be helpful if we stay civil.
So, we do have some agreement.....and while I don't wish to always be politically correct, I will try to stir up the pot less with posts for a while.....something to think about.
Bambi's friend
My personal opinion on pesticides is they are a short term solution to a long term problem with unknown consequences to the applicator, the environment, and other non-pest insect species. Pesticide application tends to not only knock back the offending insect, but many of its predators as well. Top level predators reproduce at typically much lower levels, so the bad bugs that do survive come back in force, with no natural checks in place. We don't even know what natural checks exist for this insect, but it seems short sighted to spray them and any possible predators before figuring that out. Personally, I think we are nuts to keep dumping chemicals on our problems. If I can't grow it without chemicals, then I will grow something else. I think this insect will come back into balance with the environment, as the environment (and we humans) adjust to its presence. I don't think any amount of chemical application is going to make it go away, especially if it utilizes native plants and lord help us, blackberries, in its life cycle.
I am interested in the diversity argument of permaculture, how creating multiple niches for multiple creatures creates a balanced mini environment where good and bad, predator and prey, fruit and weed all coexist together, and all serving several purposes. So perhaps nurturing spiders and predatory wasps and insect eating birds in our edible landscapes is a good approach. Fruit fly resistant cultivars (if such are possible) or other approaches (does surround work for fruit flies?) as well as chickens underfoot all sound like a more balanced and healthy set of weapons than one-spray-fixes-all. More complicated, yes. But better for us all in the long run I will wager.
BTW, keeping honeybees has changed my opinion of blackberries, as they are a primary nectar source for fantastic honey. I also feed any unwanted volunteers to my meat rabbits. 
Goats do a great job on them as well.
Thanks Don and katydid for keeping the discussion in a positive vein.
I am glad that we're all passionate about fruit growing and I think it's fine to admit that we can be frustrated or even heartbroken by a problem such as SWD.
If we start attacking each other, we'll lose our best source of help with these problems, and it won't make the SWD go away. Quite the opposite.
In my opinion, arguing a point of view is a healthy thing as long as we're not attacking the person.
Thanks for all your ideas.
Just my two cents,
John S
PDX OR
I have reread all posting in this particular forum subject. Of all the postings, only Redberry and I have actually experienced the reality of this invasive menace. If you have not experienced the devastation/problems therein, I will catagorically state that 1) you are so far very lucky and 2) any solutions you have proposed (to date) are entirely speculative.
I added my comments to inform others (BEWARE) and hopefully to obtain credible and useable information to help me deal with this menace. By credible I mean scientific (that is based on controlled and replicable studies), and/or based on logical inference from individuals with expertise.
Because of the severity of the problems I experienced (and based on my research, I fully expect that next year's infestation will be even more severe and problematic) I am extremely frustrated. It pisses me off when misinformation is presented as a solution (e. g. " GF 120 Naturalyte Cherry Fruit Fly Bait will apparently work for SWD, apple maggot, and cherry fruit flies." vis a vis http://goodfruit.com/Good-Fruit-Grower/ ... rosophila/ ). Misinformation based on speculation misguides and therein wastes time, money, and labor; and quite realistically increases the severity of the overall problem.
Thus far, I have summized that I am going to have to somehow develop a bug-proof composting system (an absolute contradiction of terms) and a fool-proof method of disposing of infected materials (how deep will I have to actually bury this stuff is still unknown). I also am going to have to somehow thoroughly inspect, quarantine, and potentially sterilize any and all produce I purchase before I bring it home.
As a first step, I am going to have to devise and initiate a trapping system that will likely have to be an on-going, year-round responsibility (as if I don't have enough work to do already).
As yet I have no information concerning natural predators (if in fact any actually exist); and no information concerning the appropriate, useful methodology and effectiveness of various pesticides, the necessary application systems for these chemicals to actually treat the different trees and plants, their application rates, and exposure safety and hazards.
I have no idea how I will address the issue of native and invasive plants as vectors of infestation. Likewise, I have no idea how I can limit infestation from sources external to my property.
Suffice it to say, if this thread is indicative of the usefulness of information HOS forum participants can provide, I will need to go elsewhere to obtain the necessary knowledge so I can somehow adapt.
Lee, at this point, there is no useful knowledge, so you aren't going to find it elsewhere, either. Everyone is scrambling to learn exactly what we are up against. At this point, everybody is just guessing and experimenting.
Unfortunately, sometimes imported pests do not come into balance, and they can do a great deal of damage to the native flora and fauna.
OregonWoodSmoke:
The fact that little or no information is available is particularly scary considering the problems I experienced last year and recognizing that next year will likely be even worse. If the problems this next year were to be proportionally worse than this year (based on the reproductive potential of fruit flies), then it might be the last year I garden (or at least attempt to grow certain species including fruit trees).
I have done considerable research and reading since my last posting in an attempt to gain some understanding of the threat this damnable invasive pest represents. I have searched the web, contacted personnel at State of Oregon Departments of Fish & Wildlife, and Agriculture; as well as Environmental Services for Marion County. I have sent e-mail messages to OSU Crop and Soil Science as well as leaving several phone call-back requests with as yet no response. I have additionally talked to the Office of my US Representative to Congress and the Office of my State Legislative Representative. I additionally contacted and had an informative conversation with someone at OSU's Fish and Wildlife Department. I sent email messages to various staff at US EPA (as they have enforcement responsibilities for agricultural chemicals and something to do with Homeland Security).
The responses thus far have provided me with the following information:
1. There are NO KNOWN/IDENTIFIED NATURAL PREDATORS -- OSU Fish and Wildlife Dept. suggested/guessed that hummingbirds, swallows and wrens could be potential predators but with the recognition that no bird species will be effective with infestation numbers of one million flies per acre. I still could not find out if the insect is active during daylight, at night or during the entire day (thus I did not learn anything concerning bats). To promote hummingbirds provide a hummingbird feeder using one part pure white sugar to four parts water (sterlized) and replaced often to avoid a contamined food source. Nesting boxes for wrens and swallows were suggested. Other natural predators (commercially marketed types) will require TEN YEARS OF TESTING before they can be approved.
2. Trapping (both for monitoring and for potential control) -- The recommended liquid seems to have gone through several changes. GF 120 is not recommended for cherries or grapes as an effective trapping/control medium. HOS Pome News Spring '10 recommended brewer's yeast with sugar in water but that is the only source recommending that mixture. OSU's site recommends cider vinegar with several drops of unscented detergent but the contact at State of Oregon Ag Department seemed to think that OSU will change the recommended trapping liquid to be a mixture of cheap red wine with some added ethanol. I expect further changes/recommendations.
Mass trapping might be useful as a control method -- using 60 traps per acre. No data is available concerning the effectiveness of this approach for minimizing fruit damage.
I would like to get some feedback about the flies' method for locating ripening fruit on which to deposit eggs and/or feeding(?). Based on Harold McGee's book "On Food and Cooking" which I was coincidentally reading, I came across the following statement: "The aromatic summer melons . . . contain active enzymes that generate more than 200 different esters from amino acid precursors, and thus help create their characteristically rich aroma." Based on my experience with how these damned pests destroyed my canteloupes, I am really curious about esters as attractants. (Esters being the combination of an alcohol and an acid -- see trap mediums above re: alcohol, and cider vinegar).
3. Composting -- as mentioned in a previous post, compost piles were recognized as "hot spots". The damned invasive pests swarmed in, on and around my compost pile such that I realized it as a problem requiring immediate attention. Marion County Environmental Services were exceedingly helpful recognizing the essential importance of composting to reduce solid waste volumes going into landfills as well as the possibility that compost piles could be significant vectors regarding the spread of this menace. As such, I was suggested to research BOKASHI COMPOSTING technology. Bokashi composting is based on anaerobic lacto-bacterial fermentation for primary breakdown. It is a layering approach where innoculated sheets are interspersed between layers of organic waste, and then the layers weighed down (so as to be submerged in composting liquid) and covered to exclude insects. It seems household volumes can be "composted/fermented" in 5 gallon buckets and for monthly volumes between 400 lbs and 10 tons (180 to 9100 kgs) a 55 gallon (200+ liter) drum system can be used. I will be recommending the HOS demonstration Orchard at Clackamas Community College immediately install a large bokashi composter to effectively manage all damaged/diseased/infected or other processed fruit wastes so it will not be an uncontrolled vector as well as it being an essential part of a comprehensive research study.
4. Native species as transmission vectors -- I have tried to obtain information regarding Asian Fruit fly infestation of native species (eg P. emarginata, salmonberry, Oregon grape, hawthorn, Oso plum et. al.). Again no data is available but it was generally recognized that such species will be vectors. So too will invasive blackberries. No one considered pesticide application to these native plants a good idea or even as a realistic approach because of pesticide impact on non-target species. How this invasive pest will impact native species of both flora and fauna is wholly unknown at this time. State of Oregon Dept of Fish and Wildlife is already overwhelmed with too many other invasive species to even consider adding it to their responsibilies (if they even had adequate funding which they do not).
[As an aside, I strongly recommend you contact your state and federal legislative members and demand that invasive species monitoring and controls be given high budgetary prioritization and that funding in these areas be dramatically increased.]
5. Emergence -- a magazine (Oregon Agriculture) I perused at Salem Library indicated that this fly will begin to emerge in February. Remember post winter emerging females have eggs that have been previously fertilized. Thus for individuals in Oregon, YOU HAVE ONLY A LIMITED PERIOD BEFORE YOU WILL NEED TO PLACE AND MONITOR TRAPS; AND BE PREPARED TO ATTACK/ATTEMPT TO CONTROL (however you deem acceptable) THIS INVASIVE PEST WHEN IT FIRST APPEARS IN YOUR TRAPS. An OSU website dealing with degree-days showed the potential for 10 generations per year in the Corvallis area.
6. Pesticides -- I could find no data regarding the effectiveness of organic approaches/organic approved chemicals. There was general agreement among individuals I spoke with admitted that the because of the reproduction capacity of this invasive fruit fly and its mutagenic characteristics, existing chemical pesticides will only have a limited period of effectiveness before the insect begins breeding/producing pesticide resistant off-spring. Misuse/misapplication of pesticides is a high likelihood.
In conclusion, there is an incredible amount that I consider to be essential, necessary information that remains unknown, and in too many instances (in my opinion) are not being investigated because of the lack of monies to fund this research. Additionally, the distribution/dissemination of materials regarding both control approaches and more importantly informing the overall populace of the potential threat of this species is significantly underfunded and/or implemented. With another yearly breeding cycle soon to begin, I find it absolutely amazing that everyone is not somehow informed -- and thus creates a situation which could allow increased spread (range area) and increased insect numbers.
Given the very real threat to our food production capacity and the economic well-being of agricultural communities and this important contribution to the overall State's economy, I am greatly concerned.
Lee-
Thanks for tireless research in suggesting means of starting to make a dent in this damaging insect. I am interested in starting wren, swallow and hummingbird homes/habitat. Sounds like a fun project to do with the kids on a cold winter afternoon.
There is so much that we don't know, but efforts like yours will make a difference when we start to get a handle on SWD. It is scary, but all we can do is head into the right direction and listen to others' efforts, sharing information when we can.
John S
PDX OR
John:
Be aware that wrens can be VERY territorial. The individual from OSU Fish and Wildlife indicated wrens will attack and destroy the nesting sites and nestlings of other wrens and other species as well. On several occasions, wrens came after me so as to indicate that I was unwelcome on their turf. As such you may want to get some information from Portland Audubon about "best site-ing" (sp???) practices vis a vis wrens and other birds. Swallow (violet-green) are airborne feeders and fly pretty high so I don't know how effective they might be for controlling flies on already infested trees/plants.
Hummingbirds are amazing so even if they only pick-off a minimal number, I will appreciate their increased presence.
Just remember, the magazine indicated the flies begin emerging in February.
I have never experienced anything like this menace before (which is why I am desparately attempting to obtain good information -- HELP ! ! !). Their numbers are explosive and the damage they can cause is horrific.
Two added comments after thinking of them as I was drifting off to sleep last night:
1. If you attrach birds, then, in my opinion, have made a moral and ethical decision to not expose them to toxic chemicals at some later time -- which will limit your choices regarding pesticides.
2. If you (or others) are building bird houses, you might want to co-ordinate with Karen (or the new Arboretum manager) so as to volunteer to make and install bird houses there. I do not recall seeing bird houses on-site and for many reasons they would make a wonderful addition. Given the Arboretum is 1.75 acres, a large marten house might be appropriate, as well as wren, swallow et. al. (Are there any birders out there with suggestions?)
I'd like to say something about the compost issue:
Hot composting produces temperatures of 160 degrees, and kills 99.99% insects as well as 99.99% of weed seed. (nothing is 100% absolute) This is great in theory but how many of us actually hot compost? To do this well IMHO you need a thermometer, lots of water, and regular turning. This is not real hard to do but time consuming, and has to be done in batches of a cubic yard or more at a time.
The most common compost pile is the one we just let set and decompose over time. This type of composting attracts insects and other pest as they are part of the decomposition process.
It might be good advice not to compost at all.
One other option would be vermiculture composting with "red wigglers" they handle food scraps and some kitchen waste. The castings from the worms is very useful in our gardens and orchards.
I hope this helps,
Randy
One of my first thoughts was Hummingbirds, too. They’ll perch near cover then dart out to nab small insects; they don’t only consume nectar. Various Flycatchers arrive in the summer but most go after larger prey, as their energy would be inefficiently spent on fruit flies. I remain impressed by the array of Swallow houses at Bird Haven when the HOS toured there a good decade ago, but agree that their higher altitude feeding would preclude fruit flies…
With ‘Humming birds’ the best potential avian predators, how could we attract and maintain enough of them to make a difference? And talk about territorial! They can’t get along at a ‘never ending’ nectar station, let alone the close quarters necessary to cover a compost pile or raspberry trellis. The only way I’ve found to attract 'a bunch' is to allow them to reach critical mass, where no one bird can run off all comers, or hummers. But in my case, that’s taken generations of human effort.
They’re not attracted to nest boxes, and often ‘follow the bloom’ to Canada, Alaska or the higher elevations of our Cascades. If there’s a reliable source of nectar (1 part sugar to 4 parts water in feeders cleaned and filled regularly - with no red dye) you can begin to attract them. But though they consume protein, their primary concern appears to be ‘nectar,’ thus fruit flies may only be a side dish to their main course.
They do cause quite a bit of aerial commotion in the vicinity of their feeder/s and will often drive away other birds. With a feeder placed near a fruit fly infestation (though that sounds to be happening nearly everywhere a fruit skin is punctured or split..) their activity alone may lessen the flies ability to congregate. …and if those waiting in line to feed notice some easy pickins ..they might make the effort to devour some fruit flies.
…but I’m afraid the fruit flies would be of little interest to most birds, and herding hummers doesn’t work… I suspect the most successful predators will come from the insect world, if appropriately so.
Randy first and then Viron:
I think that not composting is not a viable option -- we truly must reduce the amount of materials we send to landfills. Additionally, sending contaminated materials to a landfill seems to me to transport this fly to other areas and thus increase its infestation range. I obtained some literature from Marion County Environmental Services concerning Worm Bin Composting entitled "Who's that living in my worm bin?!?. Following is the information on Fruit Flies (Diptera) -- "While generally considered a nuisance, fruit fly larva are voracious decomposers of fruit and vegetable wastes and, as such, are beneficial residents of the worm bin. . . . Most fruit flies enter the system as eggs and larva on the peels of the fruits and vegetables we feed the bin. Freezing or microwaving the food scraps before adding them to the system will kill the eggs and larva preventing the flies from becoming established."
The article was written by Kelly Slocum of Bon Terra Vermi-Science (Vancouver WA) in 2001 which is pre-plague. Another article I found at a BC Ministry of Agriculture and Lands suggests tying-up/sealing the waste in plastic bags and placing these bags in the sun for three days or freezing for at least two days before disposal.
With D. suzukii, flies in the worm bin are not acceptable. My concern with both worm bins and freezing/nuking relates to the potential for reinfestation; and why now I am pursuing a bokashi approach. I think the common compost pile will still be useful for recycling yard waste, leaves and grass clippings but that for ANYTHING that might be used by D. suzukii, a bokashi system should be first employed. I will be starting a bokashi bucket in the next several days and will report my findings as soon as I am able. In the mean time, I obtained some bokashi innoculate from a company with a website (http://scdworld.net). I have yet to visit it. And yes Randy, your input is important and beneficial; Thank you.
Viron: Hummers are beautiful. I hope that there are enough around so that I can actually attract some. I hope that my attracting them will not create a risk for someone else -- I might benefit but it could be a zero-sum-gain or worse overall if bug numbers explode there and crop damage is extensive.
I am sometimes (many times) astounded by mankind's ignorance and arrogance -- such that we blithely ignore very real dangers (like the importation of dangerous plants, animals and pathogens in the name of 'free'-trade and profit maximization) and arrogantly expect the natural world and systems will be at our beck and call to clean up our mistakes and solve our problems.
With regard to natural predators, we have much to learn and we must accept that, at best, increasing natural predator populations will take many years. It is a slow process and I truly hope that the use and mis-use of pesticides does not kill so many non-target species that entire "natural systems" collapse. Pesticides to kill THE FLY will also kill the insect predators we desire -- and it seems that THE FLY has a greater mutagenic/evolutionary potential to develop a resistance to pesticides than do predatory insects. Thus the short term dependence of chemical control agents could truly create unmanageable long term problems.
I really think, that like the coddling moth, trapping will be our best "organic" option. Toward this end, I really would like to talk to some entomologists concerning THE FLY'S modality of attack specifically what attracts it to the fruits. Strawberries are red and blueberries blue so it doesn't seem likely it is some specific color. Some place mentioned sugar but sugars are odorless. Is it alcohol -- that these beasts are boozers but then how much alcohol is in a ripening blueberry? I am wondering about esters which can be very aromatic. The ultimate problem/limit however of trapping is that of mass -- compared to the overall ester production from a plum tree, how many traps would be necessary so that the traps would attract more than the tree?
Given a single female fly has 300 to 375 fertilized eggs and she lays two to three eggs on each fruit; a single female can pretty much decimate all the fruit on a good sized productive tree all by herself. If population numbers explode, there will be no way trapping could prevent damage and if population numbers become sufficiently large, the entire crop will almost certainly be destroyed. Going from one fertilized female to ten fertilized females to a hundred fertilized females (3 generations can occur in three weeks given the right temperatures) and a hundred fertilized females not only infers 3000 to 3750 eggs (worms) but also maybe a next generation of 1000 fertilized females each with 300 or more eggs. This expansion assumes that from 300 eggs only twenty will mature to fertilized adulthood which is a survival rate of 6.7%; from 375 eggs twenty mature adults is a 5.3% survival. Both values seem very low -- anticipating predation of 90% or more when no natural predators have been specifically identified. Maybe we should hope that the flies will die laughing at our species' collective stupidity and therein miraculously disappear.
Immediate and early control practices/methods are absolutely essential. This is the doom that is out there.
I as a master gardener have ties and communication with OSU and the research stations, and have had several opportunities to discuss the D. suzukii. The potential from this pest is that it can infest fruit before picking time, unlike the others that use over ripe fruit predominately.
I don't think there will ever be a one strategy fix all, I was disappointed with the post about the faith in OSU and other government agencies, We have been working had to change the chemical answer first image. IPM or integrated pest management is IMHO our best chance of acceptable results.
1.) Birds
2.) Bats also eat insects
3.) other insects
4.) companion planting of other plants, shrubs, or thees
5.) Traps and monitoring
6.) Educate ourselves and the public
7.) Cultural controls
8.) Sterile D. suzukii release
9.) pesticides
10.) Adopt a tolerance that lets some insect loss exist
11.) Organic compounds
I listed Organic last to add this note:
Organic is not necessarily, healthier, safer, less toxic
This is not a complete list but I hope it will get us started toward a useful IPM
I hope this helps
Randy
GF 120 NF Naturalyte Cherry Fruit fly bait has been used and touted by some.....but apparently, it works best where the population of SWD is low......in high populations of SWDs, it is not completely effective......and thus for anyone who wants to sell their fruit, it will not work.....because commercial growers need to be essentially 100% effective. As to what is an acceptable level for the backyard grower, I guess this becomes a debateable point.
Nevertheless, LeeN's research is more current. I did not realize that Tim Smith, the extension agent who helped to promote GF 120 NF in the first place expressed serious reservations in the Good Fruit Grower. This was not something I know and I have to rethink what I stated.
I plan to be talking with Tim in Wenatchee in about a month and I hope to approach this subject with him personally.....and could update this forum at that time.
If there are those who consider my comments/fears to be overblown and dispropotionate, and still doubt the potential threat to our nation's capacity to feed itself vis a vis Drosophila suzukii, I suggest you visit the following website:
[url:3e0jh1kn]http://entomology.oregonstate.edu/sites/default/files/DrosophilaSuzukiiInfestationModel.pdf[/url:3e0jh1kn]
Suffice it to say, on the fourth page of this report is the following statement:
" . . . remember that one female can give rise to 22,500 ovipositing daughters in only 2 generations assuming equal sex ratio, so even a few generations could mean significant damage.".
And to DonRicks, thank you for your continuing presence in this forum and your continuing desire to proactively contribute. In these times when so little credible information is available, inadvertent mistakes are likely to occur. I try to be as careful as possible but at some point in time, I will get something wrong or cite some data that has been subsequently superceded. What I consider essential is your continuing participation in this discussion and the transference of information to others.
LeeN, in some respects we differ fundamentally in our philosophical underpinnings.
However, in other respects we may be more similar than you realize.
For example, when I said something about the bugs are getting smarter and smarter I was not speaking with scientifically correct jargon. I was speaking with a "cutesy" sound bite where I thought most everyone understood what I was saying. Where I am misunderstood, then it is good to be corrected. Technically speaking, the bugs are not necessarily accruing intelligence but are adapting to become more destructive. I agree.
I could quibble with the math and the number of reproductive cycles but the essential point that you make, I believe, is a good one and it is this: When you have a fly that can reproduce in multiple generations in a single season then you have a pest that can, through genetic selection of the survival of the fittest, eventually produce a variation that is powerful. In the case of the SWD, it has now developed a serratted ovipositor that will now infect fruit EVEN BEFORE it is fully ripe and this is indeed a huge change in the picture here. (accompanying link of ovipositor.....if I did this right)
While I may have some quibbles with the context of Darwinianism, I do not at all deny the power of natural selection and this fly is demonstrating that perfectly to everyone's chagrin.
At one seminar I attended the comment was made by the speaker that this Spotted wing Drosophilia is an absolute nightmare to the organic fruit grower.
Even more importantly where we both agree is that to anyone who cares about fruit production and to anyone who would like to see our fruit production done in ways other than just using synthetic pesticides, then this SWD deserves considerable attention because it is looking like it is more potently destructive than anything we have seen......and what is additionally of concern is that with so much reproductive capacity, even to the inorganic farmer there can/may in the future very possibly if not probably be adaptations to whatever chemical is thrown at them. A very dangerous fly.
I only have container blueberries now but I want to experiment with container fruit trees......and with the use of mosquito netting over these container trees....because my suspicion is that this idea is the future for the urban grower in climates such as we have in Portland and Seattle......we grow EVERYTHING here (not literally, but figuratively)....So, in a sense, we are in paradise....but unfortunately, we also seem to grow every pest as well.....I have even heard the marmorated stink bug, to our horror, has been spotted in Seattle this past summer in isolated spots ....this is a bug that did devastation back East this past year and we have to monitor that as well in case it starts to grow in numbers here.....which it probably will.
I am not willing to throw in the towel just yet....but rather to adapt myself.....but it does seem as if the infestations keep getting more and more every year with some new bug to hit us.....and there are a whale of a lot of us that do find that discouraging.
Anyway, the passion you bring.....and your research.....and your conviction that this new drosophilia fly is not just a bug that can be easily dismissed but a serious problem .....are not only where I agree with you but support you...thanks.....and one reason to have kept this thread going for as long as it has.
I have been reading with interest the various responses in this thread. LeeN has certainly done a lot of research into the issues/concerns mentioned in this thread. When I recently checked the OSU website, the "Research Reports" section had a post/slide presentation entered on Nov. 2, 2010 titled "Drosophila suzuii, a new pest of stone fruits in Western North America" which was a collaborative effort between researchers from UC Berkeley (California), Oregon State University, and Canada. The information is directed towards commercial growers of stone fruits (eg cherry) and is not complete without hearing the verbal presentation, however. (http://swd.hort.oregonstate.edu/files/w ... 010_a6.pdf)
The slides present information that is already known from previous literature as well as the results of more recent experiments. However, they note that prior research is not written in stone when they state in one slide "General Point: presently contradictions in studies, literature, or conclusions from different regions". I thought it was interesting that even though the fly has been present in Hawaii since 1980, it has not been a pest there "under their conditions and IPM programs" though it is the most numerous Drosophila species in the traps. However, I don't know if they anticipated it to be a pest for their crops when they first discovered it. Growers in the NW may have different issues to face since the crops they grow may be more vulnerable. As it has been noted, the fly will lay its eggs before the fruit is completely ripe. In my (limited) experience, I could see the larvae damage on the inside of the raspberries with a brown discoloration. Eventually, I could tell by feel as I picked the berry which ones with larvae in them. In the worst cases, the berry would just fall apart in my hand. Unlike an apple with a worm hole in it, you can't just cut out the bad part. Anyway, back to the slide presentation...there was one slide which mentioned that they are looking for natural predators though the only (possible) one they listed was the cynipid wasp. Of course, the best predator would be one that eats the flies early in the season before they start reproducing! BTW, in Oct. 2010, it was announced that OSU had been granted $5.7 million to study the fruit fly so there is money in the pipeline.
As LeeN noted, it would be helpful to know what attracts the fly to the ripening fruit. I know some studies have looked at color preferences and red was a winner with black a second choice. However, in studies on raspberries, the flies will lay eggs to green-pink to pink-colored berries (though at a low percentage). I thought I had seen a similar study for other fruits, but I don't have it on hand.
I have not had a chance to look at references regarding the Bokashi composting method described by LeeN. However, educating the public could be another factor so that there aren't other compost areas which the flies could use for feeding. Another wrinkle is that the City of Portland is in the trial stages of getting people to put compostable materials into yard debris bins for weekly pick-ups. Will those bins attract flies with the trucks serving as a nice transport system?
As a final comment, I have pictures of my mosquito/Reemay tents that I constructed over my smallish blueberry plants which I can try and post if anyone is interested.
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