Crop & Pest Report


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Good Bug Corner - Giant Black Parasitic Wasp (07/09/15)

This week’s Good Bug Corner featured insect is Megarhyssa atrata, in the family Ichneumonidae.

Good Bug Corner

This week’s Good Bug Cornerent.knodel.4.good bug corner featured insect is Megarhyssa atrata, in the family Ichneumonidae. This giant black parasitic wasp is a beneficial insect that attacks wood borers. It uses its long ovipositor (egg laying apparatus) of 12-15 cm to lay eggs on or near wood boring insect larvae inside tree trunks. Its favorite host is the pigeon horntail, which attacks weakened and damaged trees. Larvae hatch from the eggs and begin feeding on the host larva from which they obtain all of their nutrition. They overwinter as larvae inside the horntail larva burrow and then pupate the following spring. Adult wasps emerge from their burrows and live for up to 27 days. Megarhyssa atrata are active from June through September.

Janet J. Knodel

Extension Entomologist


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