Friday, October 11, 2013

Bean Weevil Dance

Honey locust bean weevil - Amblycerus robiniae
In January of this year, Bob Korpella sent me a picture of a pile of seeds with a weevil crawling out of them.  They had come from the Nixa Early Learning Center.  We identified them as honey locust bean weevils (Amblycerus robiniae) and we described them in this blog.  I made a note to myself to check out some beans this fall.

I expected at best to find one with a larva, but was surprised to find larva in every bean in the first pod I checked out.  They were little bright yellow critters, knobby on the surface and full of life, apparently annoyed by the premature un-roofing of their hard shelled bean home.


This is the time of year that the ground under a honey locust tree will be littered with their ten inch long flat bean pods.  They appear brittle but actually are quite tough like the thorns that protect the mother tree.  Looking at them you would never guess that there was animal life inside, let alone the squirming larva you can watch in this Youtube video I posted last week.

Obviously an infested bean isn't going to be fertile but that doesn't seem to affect the honey locust population.  These trees are early colonizers of neglected fields, filling the open grass land at Jones Farm upstream from our place.  Any tree that survived the munching of giant tree sloths and mastodons had to be one tough dude/dudess.