Saturday, October 18, 2008

Who Invited this Bug to Dinner?


A recent trip to the kitchen garden to harvest some veggies resulted in a quest to identify this bug. Quick little rascals they are, I squished one before I even wondered what kind of bug it was. I could see these devils were sucking the life out of my broccoli raab so a quick search and destroy mission seemed an appropriate response from a farmer’s daughter.

Annie the garden dog was pleased with my instinctive action and soon joined in the fun hunting down and pinching them in half (that was me, Annie just chewed them up and spit them out) When we stopped long enough to admire our bug carnage the thought occurred to me to take a picture of one of these pretty insects to share with you all.

When I came back to the garden with my camera I had a hard time finding another bug on the broccoli raab. After a detailed search I did find this baby or youth bug (a nymph). He or she is really quite lovely to look at. So colorful that Annie and I just starred and took pictures and wondered why God made this pest so loud. He sure didn’t blend with his surroundings of green.

Maybe that is why every time we tried to catch one they would seem to roll to the underside of the leaf…like that would do a better job of camouflaging. Annie and I are a couple of old garden gals and we were not fooled with their hide and seek method of survival.

Turns out this cute menace is a baby harlequin. It will take 4 to 9 weeks to reach maturity (old enough to mate and lay eggs). Northerners will be happy to know this is a Southern insect. Seems they snuck in from Mexico sometime after the civil war (seemed safe then) and have since spread from sea to shining sea.

Unchecked these guys (and gals) will destroy whole crops of vegetables in the crucifer family such as horseradish, broccoli raab, cabbage, cauliflower, collards, kale, mustard, Brussels sprouts, turnip, kohlrabi and radish. In the absence of these favorite hosts, tomato, potato, eggplant, okra, bean, asparagus, beet, weeds, fruit trees and field crops may be eaten. I’m not so opposed to them eating weeds, perhaps I can now claim any weeds in my garden were allowed to grow as a trap for harlequin bugs (every gardener needs some kind of alibi).

The adult harlequin, Murgantia histrionica (I just try to remember margarita), which Annie and I have already “hand picked” so to speak are a yellow and black combination with red added in. They are basically a flat and shield shaped stink bug. When the wings are lying down it appears they have an “X” on their backs (Annie likes this easy to spot target).

The cycle of life (egg, nymph, adult) for the Harlequin is 50 to 80 days. During the winter they will hibernate in the garden and come back out ready to suck sap first thing in the spring.

Since I like to do things organically, ‘hand picking’ is an easy way to get rid of them. A great job for the kids or you can enlist a Jack Russell terror like Annie if you have one available (shoot, I will give you one on loan!) You will have to keep re-checking to get them all as they are good little hiders. Look for eggs on the underside and destroy those as well. Check too in the spring for those harlequins who dared to spend the winter sleeping in your garden.

Next step according to David Cook, entomologist working for Davidson County, TN is Pyrethrum and insecticidal soap. Mr. Cook also made the final ID on this beautiful bug (yes, I was perplexed at first). I sent the picture onto Mike Smith of Williamson County, he and I both thought it was the harlequin but David was kind enough to confirm.

David Cook also gave me to bug sites to share -
http://www.insectidentification.org/ http://bugguide.net/node/view/15740
He also recommends this book and says, “This is one of the best reference books on insects”:Garden Insects of North America, Whitney Cranshaw Princeton University Press, ISBN 0-691-09561-2
Thanks David and Mike for your help!

1 comment:

jo jo said...

surprise, surprise! Ask R if I'm still hopeless, this was really fun to read!