Subject: Large wasp-like insect. Social.
Location: Cherokee County, Iowa
July 18, 2015 7:10 am
Hello. Last week on Thursday, I noticed a large, wasp-like insect flying around a storm drain at the place where I work. Normally, I wouldn’t pay much attention, but they were in an area of high traffic, and they seemed to “multiply” as the day went along. I first noticed just the one insect flying in and out of the drain Then there were two, and by the end of Thursday, there were four coming and going. Friday’s end brought with it six insects flying in and out.
Every time a truck would park near the storm drain, all of the insects would “swarm” the truck. No one was stung, however, the freight drivers did complain about the bugs. We were forced to eradicate the nest. Inside the drain was a softball-sized nest completely constructed of mud. I witnessed one of the wasps carrying a katydid, and a co-worker of mine noticed the same thing.
I live in northwest Iowa. I have included a picture of the wasp. I was unable to get a good picture of the nest as it was inside the storm drain. Thanks for your help
This is a Great Black Wasp, Sphex pensylvanicus, and most of the information you have provided seems consistent with the recorded behavior of the species except the social behavior you stated. Great Black Wasps are solitary wasps, not a social species, though we concede that if conditions for nesting are ideal, multiple females may nest in the same vicinity. Great Black Wasps do prey upon Katydids to provide food for the brood. In an effort to educate our readership, we are tagging this posting as Unnecessary Carnage.