Column
Cicada Killer Wasps Returning and Grub Season Approaches
By John Fulton

[July 21, 2014]  Cicada Killer Wasps Returning - The cicada killer wasps have returned! They are actually considered beneficial insects because they control cicadas. This wasp gets its common name due to the fact that it hunts and supplies its nest chambers with a cicada, which becomes a food source for the young cicada killer. Other food sources could include katydids and grasshoppers. We are getting cicada killers now because of the beginning emergence of the dogday cicada. Cicada killers are a nuisance pest, especially when nesting in large numbers in a play area or near the house. People get concerned because the cicada killers resemble giant yellowjackets.

Cicada killers are about 2 inches long and black to red, with yellow banded markings on the abdomen. The head and transparent wings are reddish brown. They are not dangerous, but they are intimidating. Cicada killers are solitary wasps, with the female digging a 6- to 10-inch burrow (1/2 inch in diameter) in the ground. A pile of soil typically surrounds the entrance. The female locates and stings a large insect such as a cicada or katydid and then brings it back to the burrow. She places the insect into a chamber and lays an egg on it; sometimes she puts two in a burrow but lays an egg on only one. She then covers the burrow, digs another, and repeats the process. The egg hatches into a grublike, legless larva that consumes the paralyzed insect. Full-grown larvae overwinter in the burrow, pupate in the spring, and emerge as an adult during the summer, usually in July and August.

Male cicada killers establish aerial territories and patrol for intruders. A male cicada killer drives off other males that enter his territory and attempts to mate with females. Anyone else walking into the territory is typically confronted by a very large wasp, which hovers in front of the face and zips to the side and back. However, after determining that the "intruder" is not a rival, the wasp ignores the individual.

Cicada killers are unlikely to sting a person. Wasp and bee stingers are modified egg-laying devices (ovipositors), so males are not able to sting. Females may sting if crushed, either by being stepped on with bare feet or grabbed with bare hands.

Cicada killers are more common in areas with bare soil, so mulching, planting ground covers, or putting down sod can reduce problems. Applying permethrin or Sevin (some suggest the Sevin dust gives better control) to the burrowed area should kill females in high traffic areas. Once females are gone, males leave. In home yards, sandboxes can be covered with a tarp when not in use, as this deters the wasps (and also keep cats out). Sand below swings, jungle gyms, or other playground equipment is a popular site for the cicada killer. Raking the sand may discourage the wasps, or you could use mulch instead of the sand.

 Grub Season Approaches

Grub applications for annual white grubs should be applied about fair time through early September. Why wait when there are grubs out there now? Simply to give all the eggs a chance to hatch, without having grubs get overly large. The Japanese beetles are still laying eggs, while the June bug grubs are mostly hatched out. In areas with few Japanese beetles, applications could be made at any time. Areas with the Japanese beetle should probably wait until late August or early September to allow application closer to the time of egg hatch. Based on numbers of beetles, grub numbers should be relatively low in most places. However, there are always hot spots, and these are traditionally along walks, driveway edges, and patios.

[By JOHN FULTON, COUNTY EXTENSION DIRECTOR SERVING LOGAN, MENARD, AND SANGAMON COUNTIES]