Almost Paradise

I learned something new the other day. For years I have seen these little insects flying around, and never knew what they were:

They’re quite distinctive-looking when they land on a wall, because their abdomens bob up and down rapidly and almost continuously. What the hell were they? And those little bobbing backsides look rather ominous; do they sting? Should I be worried?

It turns out that these critters are ensign wasps. They’re parasitic wasps who are harmless to people. They lay their eggs in the egg cases of cockroaches.

When they hatch, the wasp larvae then eat the cockroach eggs, thereby ridding the world of a few dozen more roaches. In other words, these wasps are one of the Good Guys.

So if you see one in your house, don’t bother her. Just like the geckos, she’s on your side in the war against roaches. Sweet! On the other hand, if these wasps are in your house, then that means that they think there is a good chance they can find cockroaches there. Not so sweet.

And since I’m speaking of parasites, I simply must to link to Carl Zimmer’s very cool article on a different parasitic wasp that turns its cockroach victims into zombie cockroaches.

(URL to Zimmer’s article updated to reflect his address change.)

This entry was posted on Saturday, February 11th, 2006 at 11:25 am and is filed under Sci/Tech, Animals, General. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.