Blackwelder column: Cicada killers don't usually sting

Published 12:00 am Thursday, August 18, 2011

SALISBURY — Cicada killers are giant hornet-like insects that are now actively terrorizing homeowners throughout Rowan County.
Many people have called concerned about these giant “hornets” buzzing them and digging up their lawns and shrub beds. Their formidable size would seem to pose an immediate threat, especially to those allergic to bee stings or with small children. But these large, slow flying wasps do not aggressively sting like yellow jackets, hornets or wasps. They tend to be very curious and protective, buzzing people as they walk around their lawns and gardens. No one has ever complained to me of being stung by cicada killer.
Late summer is when cicada killers in our area are most active. Cicada killer males live for about two weeks, patrolling their territory and fighting with other males. Females live about four weeks, working hard digging burrows and hunting food for their offspring. Researchers have shown that in a typical season 100 female cicada killers can eliminate more than 16,000 cicadas from the surrounding area.
Cicada killer females use their sting to paralyze cicadas to feed and rear their young. A cicada killer grub will hatch from the egg in a few days, feed on the cicada and over-winter underground in a hard cocoon. It will hatch in early to mid-July, dig its way to the surface and live above ground for two to six weeks; all adults die annually.
Cicada killers can be controlled with Sevin dust near each nest entrance. Be careful not to disturb the burrow, as the female must walk through the dust for control. You may need to repeat treatments for two to three weeks if new wasps move into the area. At close range, adults can be killed with a wasp aerosol as they light on foliage or enter the nest burrow.
If you do not feel comfortable treating the area, contact a licensed pest control operator. Before using any insecticide, always read the label directions to confirm current listing of pests and follow safety precautions.
Please note: Spraying the burrows only kills the female and not all her offspring since they are walled off in chambers underground.
Another way to prevent cicada killer nesting is to plant dense, tall vegetation or mow your lawn at the highest setting during the nesting period. In shrub and flower beds make sure you have a 3-inch layer of mulch.
The wasps don’t live very long, so at most they will be a pest about two months out of the year.
Contact Darrell Blackwelder at 704-216-8970 or deblackw@ncsu.edu
www.rowanmastergardener.com
rowan.ces.ncsu.edu
www.rowanextension.com