AUGUST
1988

 

 

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

 

 

 

 

8-11-88

Killer On The Loose

West Lafayette, Ind.
There's a killer on the loose! but neither the FBI nor the local police departments are concerned. You see, this killer is of the insect kind. It's a cicada killer.

Some people are frightened by these wasps, quite understandably. Cicada killers are one of the largest wasps in North America. These rusty-brown insects with yellow stripes range from 1 to 1 1/2 inches in length. That size wasp, one is to assume, has a good-sized stinger! Indeed, the female is said to have one o the most severe stings of any insect.

For the most part, people's fear of cicada killers is unfounded. These wasps reserve most of their stinging activity for - you guessed it - cicadas. The adult wasps catch cicadas. Often the catch is made while both are on the wing. The cicada killer then stings its victim, a process that paralyzes the cicada. Before the cicada is paralyuzed, it squeals loudly. It makes quite a sight - this B-52 of the wasp world headed toward home wtih a squealing cicada in its legs.

The cicada killer uses the cicada to feed its young. The wasp first digs a hole in the ground. At the end of the hole, 6 inches or more in depth, the mother-to-be places one or more cicadas. She then lays an egg, which hatches in two to three days.

The newly hatched larvae begin to feed. The adult wasp has guaranteed a fresh food supply for her young by paralyzing the cicada. Not just any cicada, mind you, but a particular species, the dog-day cicada. the cicada is immobilized, but remains alive. the larvae keep the cicada alive by selective feeding. They destroy nonessential parts of the host first, leaving the vital organs until the final stags of feeding.

By fall the larvae have completed development. They then pupate and hibernate until the following summer, when a new crop of cicada killers begin to ply their trade.

It is the wasp's behavior in the vicinity of the nesting sites that frightens people. The wasp buzzes around, hovering menacingly, as it checks out intruders. Fortunately, it seldom resorts to warefare as a means of protecting the nest.

When in the vicinity of the nesting grounds of cicada killers, the best approach is to keep your cool. And it might be prudent to minimize noises similar to those made by a cicada!

 

Writer: Tom Turpin
Editor: Olivia Maddox