DALLAS MORNING NEWS
12:00 AM CDT on Thursday, October 15, 2009By HOWARD GARRETT / Special Contributor to The Dallas Morning News
Howard Garrett's Organic Answers column appears every Thursday in The Dallas Morning News.A reader in Krum reports a severe outbreak of a potentially dangerous caterpillar. Called asps or puss caterpillars, the fuzzy, innocuous-looking insects are the larvae of flannel moths.
The 1-inch caterpillars (Megalopyge opercularis) pack a wallop of a sting. Hidden in the ridge of the larva's silky covering are hollow spines that secrete venom. Accidental encounters, such as walking barefoot in the yard or having one drop from overhead branches into the neckline of your clothing, are the common ways people get stung.
"My husband, Tom, claims to have done in about a thousand with a hammer over the past several weeks," Penelope Richards of Krum writes in an e-mail. "I scoured the foliage around the house and killed more than I could imagine." "When we have fairly wet summers, we tend to have higher caterpillar populations," says Michael Merchant, an urban entomologist with Texas AgriLife Extension. "This is the time of year when asps finish their feeding and crawl down the trunks of trees to pupate."
If you get stung, apply a piece of adhesive tape over the sting and then pull it off to remove the irritating spines; wash the area well to remove any remaining venom.
"It's very painful," says Merchant. "Some people have allergic reactions to the stings. If you get hives or have trouble breathing, you should go to the emergency room."
If you have an outbreak like the one in Krum, you should thoroughly spray the affected trees and shrubs with spinosad and the asps with Bt (Bacillus thuringiensis). Follow the label directions, but add 1 ounce of liquid molasses to both products per gallon of spray.
Neither product will harm trees or shrubs, whereas orange oil, which also will kill the caterpillars, will burn plants' leaves if the solution is stronger than 2 tablespoons per gallon of water.
Next spring, release beneficial trichogramma wasps just as the new leaves of trees begin to emerge. The tiny, predatory wasps destroy the flannel moths' eggs before they hatch.
Howard Garrett's Organic Answers column appears every Thursday in The Dallas Morning News.Read more on this interesting creature on the website www.DirtDoctor.com
click this link: http://www.dirtdoctor.com/organic/garde ... n/id/2936/