So I went out to harvest beans yesterday and guess what I found?
You know what those fat, yellow, fuzzy suckers are? Mexican Bean Beetle larva. And they seem to have prodigious appetites.
While harvesting beans from my bush plants (barely any nibbles on those plants) I noticed that the leaves of the bean tee pee were looking much more chewed than they had previously. Previously I found only two adult beetles on the tee pee. It seemed almost immune. Not so, obviously.
The Mexican Bean Beetle is the black sheep of the ladybug family. Ladybugs eat other damaging bugs in our gardens, but the Mexican Bean Beetle likes to chomp on bean leaves (and the beans, too!) RJ, my nine-year-old, was most upset when he thought I was drowning ladybugs. Here is what the adults look like. (Most of mine have been bright red, but some were paler yellow-orange).
I know my picture of the larva is rather hard to see, so here's a much better picture I found on the 'net:
My shoulders are actually sore from picking these suckers off my bean leaves and drowning them. There were SO MANY of them! I know there are more, but my soreness turned into a pinched nerve and ended my bug harvest. Hubby's out picking them now. I don't know why the beetles decided to go and lay their eggs on my tee pee plants since those were not the plants with the most beetles on them. I guess they figured there wasn't much eating left on the other bean plants.
Relatively few of the beans were damaged. I picked about 4 quarts and tossed only a handful, so at least they're not overly damaging the harvest. I understand later in the season they will go after the beans more.
I had sprinkled the leaves with diatomaceous earth, but it seemed to do nothing to deter the nasty bugs. Next year (it's too late this year) I could order the spined soldier bug from Natural Insect Control, a local company. They're rather expensive for the small number of plants in my home garden, though. I can also erect finch feeders near my bean plants, which is what I will most likely do. Finches will happily snack on Mexican Bean Beetles. I will continue to handpick and drown (in soapy water) the adults and larva I find. I could also try to find a supplier for the parisitic wasp Pediobius foveolatus. Price is a factor. I truly cannot afford to spend $100 on bugs to kill bugs in my garden, nor would I need as many as $100 would buy. That kind of expenditure completely negates the frugality of home gardening.