Subject: Large wasp
Location: Gaithersburg MD
August 5, 2012 1:42 pm
I live in MD and have a lilac bush that is now covered with what appear to be giant wasps. There is ”saw” dust at the base of the tree, there is a sweet odor, and there seems to be several dead limbs now on my bush. The wasps seem to be eating into the tree and are about 2 inches long. They are congregated at the base and several limb joints.
These are Cicada Killers and though they are feeding on the sap produced by the lilac bush, we do not believe they are responsible for the poor health of the plant. The sawdust and dead limbs are most likely due to some other cause. Perhaps some other insect is compromising the health of the lilac shrub, and the result is the sweet smelling sap that the Cicada Killers are feeding upon. Cicada Killer females prey on Cicadas to feed their broods which are found in subterranean nests. Cicada Killers are solitary wasps, and despite their large size, and their habit of defending territory, Cicada Killers are not prone to stinging humans.