September 27, 2006 Leave a comment
David and I just finished watching a great nature documentary, “Life in the Undergrowth.” This terrific documentary following the lives of insects, spiders, slugs, and other creepy-crawlies is the latest in a tremendous “Life of” series of documentaries by Sir David Attenborough (earlier efforts included Birds and Mammals). In quite a interesting coincidence, by favorite podcast, Quirks and Quarks, back from a summer hiatus had a feature this week about one of the insects featured in the series, the blister beetle.
In an amazingly complex and sophisticated feat for an insect, here's what they do… the tiny beetle larvae climb up the stem of a small desert plant, they group together into roughly the size of a female solitary bee and release pheromones that mimic those of the female. The duped male comes into mate (psueudo-copulation being the scientific term for this) and soon discovers he's covered in beetle lavae. He recovers, flies off, and when he finds a real female to mate with, the beetle larvae jump on her. She unwittingly takes them into her desert burrow where they feed off the food she brings for her own larvae, before devouring it, becoming adults, and starting the whole cycle over again. Pretty amazing.
As amazing as that is, I found the amazing adaptation of a particular ichneumon wasp even more fascinating. The caterpillars of the blue alcon butterfly mimic both the pheromone and smell of ant larvae so that they are taken into ant nests and fed and cared for along with the ant larvae. They are reasonably good uninvited guests, only taking the food and care before becoming butterflies, not eating the ant larvae. While the ants are completely fooled by this, the ichneumon wasp is not. Somehow it detects which nests have the caterpillars inside, flies in, and when attacked by the ants releases a pheromone that makes them attack each other instead (perhaps the military should be investigating this). Once the ants are busy attacking themselves, she lays her eggs in the caterpillar. A few months later the caterpillar goes into a cocoon and what emerges is not a butterfly, but an adult wasp.
“You're writing about the bugs?” Kim asks looking over my shoulder. But I just thought these were such amazing things in the insect world that more people should know about them. If you don't agree, you probably didn't make it to this point in the post anyway.