Re: [CH] Good bugs or bad bugs?
Brent Thompson (brent@hplbct.hpl.hp.com)
Wed, 09 Sep 1998 09:15:52 -0700
> They are flying (beatles mayhaps?) kinda similar to ladybugs in shape,
> but yellow with black spots.
These are almost certainly Diabrotica, a bad bug -- a very bad bug. I
believe the main damage caused by adults is concentrated on flowers and/or
fruits, causing deformation or abortion. So we don't want them around our
gardens. From what I read, the larvae are perhaps a bigger pest, but
attack roots hence cause damage indirectly through decreased plant vigor.
Anyway, it's the adults which commercial fruit growers in California are
concerned about (maybe the larvae don't dig deep enough to affect tree
roots much, just deep enough to eat vegetable roots :-) ).
Diabrotica is the genus name, which is the name commonly used in the
agricultural community in California -- though it seems it is sometimes
also called by "common names" including Spotted Cucumber Beetle and
Southern Corn Rootworm (the larvae, in this latter case of course).
Diabrotica is usually described as yellowish-green with black spots, and as
mentioned is about the size and shape of a ladybug (though head maybe
sticks out a bit further than a ladybug's).
Ladybugs are red, or some related color (red, red-orange, orange,
brownish-maroon nearing black, etc.), and have varying numbers of spots,
from only 2 (or even zero?) to at least 11 or 12. Ladybugs are never green
or yellow.
Leave the red/orange/brown/black ones alone. Get rid of the yellow-green
ones.
--- Brent