Ask A Scientist Zoology Archive

name         Martha H.
status       other
age          60s

Question -  I have a question about Yellow Jackets. Are they more abundant this year? If so, 
why? Also, how does a homeowner control them inside the house and out?  I am in Greenville, 
Michigan.              (September 2003)
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Yellow jackets are typically abundant in late summer and early fall. I have not seen any thing 
in NE Illinois to indicate they are more numerous this year than others, but it may be 
different in your area. Only the queen overwinters and the hive numbers build up over the 
warm months until they peak in early fall. There are two common species, a native American 
one that nests in the ground, and a European ("German") species that typically nests in 
crevices or other openings in buildings. You can spray into the opening that they go in and 
out, with an over-the-counter commercial wasp and hornet spray. Spray after dark when the 
insects are all inside - they do not fly at night. It may take several sprays to kill them, 
as the nest may actually be some distance from the opening. A powdered insecticide called 
"sevin" can be placed at the opening so that when the insects land they pick it up on their
feet and carry it into the nest, which can be very effective if the situation allows proper 
placement. If they get inside the house its probably best to use a good old fly swatter or 
the like, or open a window and shoo them out if that is possible. If they can get inside the 
house from the nest, they may well try to escape that way if you spray so be careful.
    Yellow jackets, while very annoying to people, do serve a useful ecological function - 
	they are primarily scavengers, one of the host of creatures that help "clean up" the 
	outside world.
	
J. Elliott
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