Episode Details

The Emerald Jewel Wasp brings new meaning to the phrases “eating out” and “having someone over for dinner”.

The Emerald Jewel Wasp is an amazing example of “Extreme Evolution.”  They propagate their own species by stinging their prey — cockroaches — three times in a very carefully orchestrated dance.  

The first sting is directed at the mid-section of the cockroach to briefly stun and paralyze it for only a minute or two, while the wasp re-positions itself for the second sting.  The latter is directed at a soft spot underneath the “chin” of the cockroach, and with surgical precision aimed at a very specific brain region which controls the cockroach’s “escape reflex.”  This essentially lobotomizes the cockroach, making it completely compliant to the wasps commands while leaving other parts of the brain intact to activate the “walking reflexes”.  In this state, the wasp can lead the non-resistant zombified cockroach, like a dog on a leash, into an underground burrow, where it lays an egg in the “armpit” of one of the legs and then covers up the entrance of the burrow to trap the cockroach inside and keep other predators out.

In the meantime, the egg hatches and a jewel wasp larva crawls out and begins to eat its way through the entrapped cockroach.  But that baby dines in a very careful, strategic, pre-programmed way, eating certain internal organs and not others, in order to keep that lethargic cockroach alive for many days.  Eventually, though, enough of the cockroach is eaten that it finally dies.  A couple weeks later, a brand new Jewel Wasp chews its way out of the dead husk of that poor victim and flies away, to repeat the cycle.

The precision and orchestration of this reproduction strategy is simultaneously fascinating and horrifying.

As always, tell us your thoughts on this topic …

You can find more information about our guest  — Dr. Ryan Arvidson — at his faculty page at the university.

Episode image by Andrew …… Thanks Andrew!

If you enjoyed this episode, you may also enjoy several of our previous episodes collected thematically under “Human Evolution.”

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