Troup County Extension agent: Interesting insects: Cicada killer wasp

Published 12:00 am Friday, August 21, 2015

Brian Maddy

Contributing columnist

Every week we have folks that bring in some interesting specimens of insects and plant material. We’ve also get calls that get or attention as well.

A gentleman brought in an intriguing wasp specimen. The cicada killer wasp is a giant killer.

You may hear all that singing each evening at about dusk. Those are the male cicadas trying to attract a mate. They emerge from the soil and climb trees as they shed their skins.

The cicada killer is the largest wasp in Georgia. The female may get as large as two inches but she needs all the bulk she can garner to haul in a cicada.

She has no preferences between male and female cicadas. The male cicadas hatch out about two weeks before the females.

They are solitary ground wasps that buzz around until the female hatches and are ready to breed. Both are non-aggressive and will avoid humans unless you step on them. The female can sting but according to the experts it’s rare and nothing like the sting of a yellow jacket.

The male wasp, after much competition from other male wasps, fertilize the female. She determines the sex of the offspring by keeping the sperm separate from the eggs. If she wants a female baby, she lays an unfertilized egg and if a male is desired, she allows the egg to be fertilized.

The female cicada killer is much larger than the male. Size is determined by sex and feeding. If she lays a female egg, she provides two to three cicadas that have been stung and immobilized.

The venom that she uses keeps the cicada alive and mold free until the egg hatches under a tender arm of the cicada and the wasp larva starts to feed. She only provides one cicada for the male, hence the size difference.

She has special appendages on her legs that allow her to be an excavator machine that can tunnel up to three feet underground and dig multiple galleries.

She lands on a cicada, stings it, straddles it and tries to fly carrying the cicada to the nesting area. This may be a big struggle since the cicada may be four times her size. She may be doing a lot of hops and jumps until she finally drags it to the nest.

The nesting sites may vary from bare spots in the lawn to cracks in pavement or in stonewalls. You can usually spot the excavated soil at the point of entry. The females can lay approximately three to four female eggs per 10 hours and around six males per 10-hour day.

The male cicadas meanwhile act as protectors by dive bombing predators and distracting the cicadas so the female wasps can have successful hunts.

Cicadas damage deciduous trees, hardwoods, by drilling into the tender branches to lay eggs. A gaggle of cicada killers can kill over 11,000 cicadas. The females live approximately 34 days. They are very industrious and are beneficial insects.

What’s going on in Extension?

Market on Main begins Saturday mornings from 8 to 10. Come by and enjoy the pick of the day. Carmike Cinemas LaGrange 10 movie theater parking lot.

Sept. 15: Troup County Cattleman: Forages and Nutrition; Dr. Lawton Stewart, guest speaker; 7 p.m. Tuesday; program will start at 7:30 p.m. The $6 meal will be served at 7 p.m. Ag Center.

Sept. 21: Troup County Association of Beekeepers; 7 p.m. at the Ag Center.

Sept. 24: OSHA Chainsaw Class, 8 a.m. to 4 p.m. Call the office for details.

If you have any questions or concerns, stop by or call the office.

Brian Maddy is the ANR Agent for Troup County Extension. The Troup County Extension office is located at 114 Church St. in LaGrange and may be reached at 706-883-1675, Monday–Friday 8 a.m.–noon and 15 p.m.