Posted 25 June 2012. PMN Crop News.
Big, Black Grasshoppers Arrive, but Cause Little Trouble
Source: Louisiana State University Press Release. www.lsuagcenter.com
Baton Rouge, Lousiana (June 7, 2012)--The big, black eastern lubber grasshopper has started making its appearance in southern Louisiana. But its frightful look should be no cause for alarm, said Tim Schowalter, LSU AgCenter entomologist and head of the Department of Entomology.
These grasshoppers, also known as Devil’s horses, can reach 4 inches in length and are the largest grasshoppers in the United States. Adults, which are solitary, typically are black with a red strip down the back and have short patterned front wings covering short red hind wings.
“They are unable to fly and jump clumsily,” Schowalter said.
The boldly colored nymphs are black with one or more distinctive yellow, orange or red stripes.
“The nymphs are gregarious and typically associated with wet sites, where they feed primarily on weedy vegetation such as nettles and pokeberry,” Schowalter said.
Though conspicuous, the grasshoppers cause little trouble. They can accumulate along weedy, wet drainage ditches or field margins and then feed on cultivated crops or ornamental plants, especially amaryllis and related flowers.
“Keeping vegetation mowed will discourage their presence,” Schowalter said.
Although harmless to people, the lubber can cause birds and mammals to vomit violently if they eat it. Lubbers also secrete a foamy spray, accompanied by loud hissing when handled. They will regurgitate recently-consumed plant material as a dark brown liquid, commonly called "tobacco spit," which can stain clothing, Schowalter said.
If lubbers are seen damaging crops or ornamental plants, they can be killed by hand-picking and throwing them into a bucket of soapy water or a trash bag, Schowalter said.
If there are too many to control by hand-picking, you can use an insecticide that contains carbaryl, bifenthrin, cyhalothrin, permethrin or esfenvalerate as the active ingredient, Schowalter said. It must be applied directly on the insects. Small amounts of insecticide residue on sprayed plants may not be adequate to kill these grasshoppers.
“For safety reasons, always follow the directions on the label when using insecticides,” Schowalter said.