Rose Midge Fly....question on control?
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.