Aug. 5, 2003

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COLLEGE STATION – Summer's hot weather is stirring up two irritating insects -- cicada killers and their noisy prey, cicadas.

Dr. John Jackman, an entomologist with Texas Cooperative Extension, said cicada killers – wasps that can grow to 1.5 inches in length – paralyze cicadas with their stings, drag paralyzed prey to their sandy, burrowed nests, lay eggs upon them and allow their larvae to eat the captive cicadas.

Only cicada killers' larvae eat cicadas, he said. Adults feed on flower nectar.

"They're large enough that when you see them, you get concerned," he said. "They'll fly at you, but they're only bluffing, trying to chase you away from their nests. They almost never sting."

Jackman said he has never heard of cicada killers stinging people; they might sting if captured.

"It's not likely at all," he said. "It just bothers people when cicada killers fly at them."

Jackman said aerosol insecticides hardly knock down flying adult cicada killers, but changing the texture of sandy soil, planting groundcovers or covering sandy soil with plastic might help control them.

Controlling cicadas ought to help control cicada killers, but he said cicadas, insects with oversized eyes, transparent wings and musical membranes in their abdomens, cannot be controlled.

"There's not much you can do to control adult cicadas but to wait them out," he said. "You could spray insecticide, but that becomes a question of where to start and where to stop."

Jackman said spraying trees from top to bottom and killing each and every cicada seems useless because more would fly into those trees within days.

Adult cicadas spend their summer afternoons in treetops, he said, where adult males make music to attract females with two vibrating membranes in each side of their abdomens.

"They're the guys that make the big, loud buzzing sounds in the heat of the day," he said.

Jackman said adult cicadas use their beaks to suck nectar from twigs, and females lay their eggs in twigs, which causes some twigs to snap. Within weeks, cicada nymphs hatch, fall and burrow into soil, where they feed on tree roots and mature for three to 17 years. Overall, he said, cicadas cause little damage to trees.