Thursday, August 4, 2011

Sounds of Summer: Part 2 - The Cicada Killer

At the end of our last post I mentioned the Cicada Killer, a large predatory wasp. In the interest of giving both 'pest' and prey their due, here is some info on this BIG (but harmless) bug.

The cicada killer wasps attract attention due to their large size, the burrows that they dig in home lawns, and their buzzing flights over the lawn. These insects occur in all states east of the Rocky Mountains and prefer to dig their burrows in sandy, bare, well drained soil exposed to full sunlight. The wasps feed on flower nectar while the immature or larval stage feeds primarily upon cicadas that are brought to the burrow by the adult.



In spite of their large size, the wasps usually ignore people but they can give a painful sting if bothered. Mating males are aggressive and more easily disturbed. A mound of fine soil surrounds the burrow of each cicada killer. Since colonies of burrows are common, infested lawns usually contain several mounds that can smother the grass. However, they prefer to nest in areas of sparse vegetation, and rarely infest thick,vigorous turf.

Cicada killers over winter as larvae in the soil. Pupation occurs in the spring and the adult emerges in mid-June to early July. Emergence continues throughout the summer. Females feed, mate, and dig burrows for several weeks before preying on cicadas. Excess soil thrown out of the burrow forms a regular, U-shaped mound at the entrance.

The females search tree trunks and lower limbs for cicadas. The wasp stings its prey, turns the victim on its back, straddles It, and drags it or glides with it to the burrow. Each cell is furnished with at least one cicada (sometimes two or three) and a single egg before being sealed off. Two to 3 days later the egg hatches. Depending on the number of cicadas in its cell, the larva feeds for 4 to 10 days until only the cicada's outer shell remains. During the fall, the larva spins a silken case, shrinks, and prepares to overwinter. Only one generation occurs each year.

(Information courtesy of The University of Kentucky, image from Purdue University)

No comments:

Post a Comment