Without having researched this garden interloper, I can say that I have not really seen problems due to their presence. I have a lot of containerized plantings and I rarely see them in them there. (Maybe helped out by all the birds I have attracted to feeders.) I would say though, that I feel that their overabundance is probably a sign of excessive moisture (to the point of being detrimental to a lot of plants), and also possibly a sign of decaying wood (turn over any log and you'll find them). Increasing ventilation and increasing UV sunlight by doing judicious pruning of existing shrubs might be useful. Also maybe by not mulching too close to plant stems/trunks?) Like a lot of things in the natural world there seem to be cycles of population explosions and declines. Several years ago, we had an explosion of lightening bugs (fireflies) in my yard. It was like a show from Disney..., this year, not so much.

Pyrethrum based sprays and dusts are very broad spectrum poisons and should only be used as a last resort means of control, not among the first things to use. Maybe the Insecticidal Soap might be effective, but it usually is not if these are the Gypsy Moth larva. If these are leaf chewers something that is very effective is Bacillus thuringiensis - Kurstaki, a bacterium, a disease that will kill leaf eating insect pests and only leaf eating insect pests. The target pest must ingest, eat, this while eating the leaf and the spores grow in that insects gut and stops them from eating and they starve to death. A good means of control is to remove the egg cases from whereever they are in the fall and winter. The Gypsy Moth puts these egg cases every where, I find them on tree trunks, one my trailers, on the side walls of the sheds, and those I find I destroy. Here is a link that might be useful: Gypsy Moth egg cases

Well, There is good news and bad news... First of all, the good news is that honey bees and hornets are totally of a different nature. Honey bees survive winters by keeping each other warm while not leaving the nest. You can even move them from one place to another. They are beautiful and very beneficial to all plant life including human.... I would love to have these around for many useful purposes. As for your yellow jackets.... They too are beneficail to nature and they will die off if the nest is partialy exposed to those kind of winter temps kimmsr is talking about. BUT, the bad news is that, if their nest is to deep in your foundation, or you have no idea where it is, there could be a problem. They will survive the winter if to deep where they can stay a bit warmer than you expect, yet they will slow down quite drastically, be lethargic, almost asleep. But they WILL survive. The only way you can get rid of them if they are not going to die off, sadly, is by extermination. Now I am not a fan of this or of any kind of mass murder to insects beneficial to our enviroment, but that is the only way to rid them, SADLY. There a powder you can buy that you can place at their entry way, that gets on their fur and wings, which in turn they carry to the nest, rubbing it all over the others. Your local extermination office should have this stuff, or you can hire a professnonal to do it..To bad they have to loose their natural habitat to human developement..:-( Hope this helps....Goodluck.

You need to let us know where you are as well. Geographic location often dictates what sort of weedy plants are likely to be found. And photos of any with leaves still attached - or starting to emerge - are very helpful as well.