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thorntorn

Rose Midge Fly....question on control?

Thorntorn
11 years ago

If you live in an area where severe infestation by rose midge fly is a perennial issue, as mine is, and you have a successful control, please share it.

Starting in May I used Bayer Complete Insect Control (1 tbl./1 gal. water), as a spray every two weeks. I sprayed, concentrating on the growing tips until developing buds were about 3/8" across for an average hybrid tea. For floribunda and polyantha types spraying was discontinued earlier in bud formation since the blooms are smaller. My premise is that if a bud develops to this point, thereafter the midge usually leaves it alone, and it develops normally to complete its blooming cycle showing no midge damage.

Immediately after deadheading a rose, the dormant buds that start to awaken below the cut are given careful attention during the spraying sessions because I noticed midge fly damage starting on them shortly after they started to elongate, at about 2-3 inches length, long before an even vestigal bud started to show.

The above method was not 100% successful, but about 85% control. Otherwise I will have NO ROSES at all, all summer, after about a 50% damaged first spring flush, if not sprayed. That's how bad the Midge is here.

I am essentially a no spray rose person. The only exception I make is for Midge.

In July I decided to do a soil drench as prescribed on the Bayer insecticide bottle. Using a watering can I applied the drench directly on the two inch layer of cedar mulch that covers my rose bed. With this method I was pleasantly surprised with about 90% buds making it to blooming. By the end of September, three months after the drench, midge started to show up with a vengeance, indicating a return to tip spraying or a second drench was in order. I tip sprayed since I believed a drench that late was a waste of product, more from the premise I do not like any chemical use if possible, not from being too cheap to waste it.

I am not sure what route I will pursue. I am leaning toward drenching the soil every three months starting in spring, but it is not easy to satisfactorily drench a large rose bed during the summer, dense with foliage.

Any comments, observations, advice, is most welcome.

Throntorn

Comments (6)

  • dan_keil_cr Keil
    11 years ago

    I think that an application of Merit granules will do a better job. There are several cycles a year and the only way to control them is kill the larvae in the soil before they come back out as an adult to lay another egg!
    I sure wish we had diazinon again!!!

  • harryshoe zone6 eastern Pennsylvania
    11 years ago

    I have found that only repeated soil drench applications make a difference. I think it is necessary to apply 3 or 4 times about five days apart in order to break the mating/larva growth cycle. I use Bayer Complete Insect Killer For Soil and Turf.

  • marcindy
    11 years ago

    Harryshoe, have you seen subsequent outbreaks after your rounds of treatment, once you got the initial outbreak under control? I wonder if one can truly eradicate midge from ones garden, which would make subsequent outbreaks a result of midge from the "outside" brought to ones garden? Or do you think the 4 to 5 rounds of treatment are sufficient for a season, or 'for ever" (unless new midge brought in with new roses)? Very interested in people's experiences.

  • Thorntorn
    Original Author
    11 years ago

    My initial drench gave what I consider acceptable control for about three months.

    That is, on any one mature, established bush like Quietness (although classed as a shrub rose, it is undeniably, essentially a grandiflora), for example, of the five bushs in my rose bed, there were only one or two 'midged' growing tips per bush during the initial three months after drenching.

    Without chemical intervention the Quietness bushes would be flowerless all summer well into fall.

    I believe Harryshoe method bears very serious consideration if by its implementation a permanent eradication of midge would be the result.

    My initial concern is what would prevent reinfestation of midge fly by newcomers flying into my garden from my neighbor(s) gardens who if they even have a rose or two, do not even know what a midge fly is.

    Also, several drenches in such close succession would definitely make the soil super toxic. The soil drench rate being several times heavier than the foliar spray rate.

  • harryshoe zone6 eastern Pennsylvania
    11 years ago

    I have tried drenching with a one or two shot application. In these cases, the midge numbers were greatly reduced, but returned in force by the end of the season. I think I drenched three times within 3 weeks in 2011 and didn't see them last year.

    Remember, just because you don't notice them, doesn't mean they are gone. They are really small. Occasionally I would see them flying in the evening when the sun was low.

    I don't think spraying the growing tips gives much relief. It also doesn't seem that the systemic effect within the plant nor the long-term effect in the soil does much good. Even though the package label seems to say otherwise.

    Midge don't appear to have the power required for long flights. The wind is likely to carry them some distance, but they would then need to find a mate and a rose plant to keep the cycle going.

    I do not like to spray insecticides. The soil drench process just plain disgusts me. To go to so much trouble building up my soil with organic amendments and attracting earthworms and other good guys ....only to drown them in toxic chemicals is so sad. However, my conclusion is that if I don't spray these little devils, I will just have to dig up my roses and plant something else.

  • marcindy
    11 years ago

    Thorntorn and Harryshoe, thank you very much for your detailed explanations. I agree that soil drenches are only a last resort for many, and it is physically painful to do that to your own yard after years of careful cultivation. However, the other undeniable truth is that without a drastic step one is forced to remove all roses or live with green thorny flowerless shrubs. I have done that for a few years until this fall when I dug up all remaining bushes and plan to have an "off" year without any rose bushes in my yard. I hope this drastic step will eradicate the little monsters from my yard. I kept two rose bushes which are away from others. These two I will cover the ground with newspaper while the ground is still frozen and give several treatments of soil drench later in the season. Spring of 2014 should see a return of a few rose bushes to carefully monitor any potential midge return. 2015... planning to go all out...lol

    Thanks again for sharing your experiences.