If you happen to see insects that look very much like lady bugs except they are yellow…and they happen to be eating away at your bean plants, you have just met the Mexican Bean Beetle. These little buggers are one the the most destructive bean plant eating beetles out there.
If you did not spot the yellow eggs on the underside of your bean plants then you may see something that looks like this on your bean leaves:
If left alone, they will turn into something that looks like this:
And then they grow up to look like this… and they multiply:
I inspect the underside of the leaves on my bean plants once the leaves really start to form and I try to pick off the eggs before they hatch. If I miss them – I pick off the larvae… and if I miss those, I pick off the adults before they destroy the whole bean plant.
Here is a link to more information on th Mexican Bean Beetle as well as some tips on how to get rid of them: