Question
We live near Washington DC in a cottage, in a tightly packed neighborhood, on a ridge overlooking several homes, a major road and across the road, the county's water treatment center. We have lived here for seven years. We have what we believe to be an infestation of midge flies which we think come from the water treatment center. They rise in swarms from everywhere in our yard when we walk by - the lower branches of our large old oak tree, the azaleas, cedar and other evergreen trees, juniper hedges, laurel hedge, winter jasmine, maple trees, the crepe myrtle, mums and rosemary.  Have not really noticed them in the monkey grass but that could be because the other bushes are knee high to very tall so the midges coming out are more in your face.  The land all over the white vinyl siding as well as the black cover to the gas grill. They are equally in the sun and shade, and get inside the house and in the cars. The swarm around the porch lights and in the windows - I guess attracted to the lights. The are out all day from ealry morning into the night. We have some impressive spiders in the windows and around the porch that feed on them. They do not bite, but are just very annoying. They seem to like intense heat and sun, as well as cool, rainy weather. They have started to slow down a bit with very cool nights, but we still see them now in November. It seems odd that the playground has none - not even around its lights at night. Like Jack in NJ with a different insect, we have sprayed which kills them for a few hours, but they are back and just as intense the next day. At one point an exterminator sprayed the siding next to the front porch, and we had an ongoing layer of dead midges at the base of the foundation for some time.  We have kids though, and did not like the idea of having a strong pesticide that close to the house. We had assumed after tons of research that these are from the water treatment center and just the plight of the neighborhood. We noticed that a block away, at the local playground which has a parking lot and tennis courts lit at night with white street lights- there are no midges. I cannot imagine that our "no spray ever" county treats that park chemically in any way. Other people in our neighborhood have mosquito problems, but not midges. We do have a lot of trees, shrubs and debris from the oak tree, but even when we clean that up the midges do not go away.  Many of our neighbors also have a lot of shrubs, trees, English Ivy, etc. Interestingly, we don't have a mosquito problem. I think that our immediate neighbors do have issues with the midges as well, but a block away - no problem. From what I have read about them, they should be all over the neighborhood if they are in fact coming from the water treatment center. So my questions: 1) why do they like our house and yard above others, and 2) how can we get rid of them. Maybe the white siding? Maybe they are breeding here and not in the water treatment center. It just seems odd that they hover here and don't move up the hill to the park at all.

Answer
Tam,

I think your analysis is correct. Midges (Chironomidae) develop in standing water and waste water ponds are a common source of these insects. Most waste water treatment facilities have programs that manage these flies so I would start by talking with whoever is running this facility. No amount of spraying of insecticide at your house will control the flies, they must be managed at the source.

I would talk with the water treatment folks first then the county commissioners and so forth until you get a promise that they will manage the flies. You may have to become a bit of a "pest" yourself.

Post a follow up if you have questions.

Jack DeAngelis