GEN-ERIC News

Fortunately, the boll weevil (Anthonomus grandis), which devastated U.S. cotton crops for much of the 20th century, is now found only in parts of the mid-South and South Texas, thanks to eradication efforts. But monitoring weevils to keep track of where they are coming from—and where they’re going—is vital for protecting cotton crops in the United States. Agricultural Research Service (ARS) entomologist Tom Sappington works in the ARS Corn Insects and Crop Genetics Research Unit at Ames, Iowa. He has tracked local weevil movements by marking the insects with enamel paint or fluorescent powders and recapturing them later. Now he uses “microsatellites”—short, repetitive DNA sequences—and population assignment tests to find out where weevils in different populations have come from. These tests help pinpoint the migratory patterns and origins of boll weevils over long distances.