04 June 2009

adding insult to injury in the insect world

from here:

There are numerous parasites and predators of cockroaches, but few of them have proven to be highly effective for biological control. Wasps in the family Evaniidae are perhaps the most effective insect predators, as they attack the egg cases, and wasps in the family Ampulicidae are predators on adult and nymphal cockroaches (e.g., Ampulex compressa).


Ampullex wasps sting the roach more than once and in a specific way. The first sting is directed at nerve ganglions in the cockroach's thorax; temporarily paralyzing the victim for 2–5 minutes, more than enough time for the wasp to deliver a second sting. The second sting is directed into a region of the cockroach's brain that controls the escape reflex among other things.[28] When the cockroach has recovered from the first sting it makes no attempt to flee. The wasp clips the antenna with its mandibles and drinks some of the haemolymph before walking backwards and dragging the roach by its clipped antenna to a burrow, where an egg will be laid upon it. The wasp larva feeds on the subdued, living cockroach.

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