Question My new tenants want to use a tiny gas fireplace, but there is almost certainly a wasp nest inside the chimney. (Live solidly-colored dark-orange wasps have come out, together with about 40 dessicated carcasses when we opened the flue (a disc shaped buttefly valve)). This particular species is endemic to Georgia, though I'm unsure of the proper name. They sting fiercely and build paper nests in which the hexagonal brood cells are visible (at least at first). I can't light a roaring fire because the chimney is too small. I fear a large gas flame would be insufficient to deter them from flying down the chimney to repel my attack. Placing a wire screen over the bottom of the flue appears difficult to implement. I'm not sure about the top of the chimney. What do you suggest?
I think the safest approach would be to temporarily seal the bottom with rags then treat from the top with one of the botanical insecticides (see http://www.livingwithbugs.com/botanical_insecticide.html) such as EcoPCO Jet. Once the nest is destroyed have a chimney sweep clean out the entire chimney and remove the bottom seal.
I can answer questions about the control of pest insects, spiders, mites and related arthropods. These household pests include termites, carpenter ants, powderpost beetles, nuisance ants, bed bugs, cockroaches, fleas, wasps, and many others. I can also answer questions about using pesticides and other pest control tools such as baits and traps.
I am a retired university extension entomologist. I've taught and conducted research in urban and agricultural entomology. I've published over 70 extension publications, 20 research publications and several books about insects.