Taking on a Tough Pest

The Russian wheat aphid impacts wheat growers across the country. A new tool can help track this bug.

Published on: May 9, 2012

What do you do about a pest that can cost an industry up to $200 million in annual losses? You start finding new ways to track it down. The Russian wheat aphid started dining on U.S. wheat back in 1986 when the first bugs appeared in Texas. Now USDA scientists have come up with a way to track the bug that is a worldwide threat to wheat and barley and by tracking the bug researchers can learn new control strategies.

The researchers actually developed a kind of DNA barcode to identify changing biotypes of the wheat aphid pest. With the barcode, scientists sequence a designated part of an organism's genome. From that they build a kind of barcode that allows systematic comparison with the sequenced DNA of other closely related species. Sounds complicated, but it can act as a faster early warning system to changes in aphids than simple observation.

The Russian wheat aphid impacts wheat growers across the country. A new tool can help track this bug.
The Russian wheat aphid impacts wheat growers across the country. A new tool can help track this bug.

The way to battle aphids is to use resistant wheat varieties, but a new biotype overcame resistance back in 2003, which forced reliance on pesticides while breeders develop new resistant varieties. Monitoring that population for emerging new biotypes is important. USDA points out that knowing if new biotypes are developing will help breeders enhance development of new wheat lines.

How can they tell a new biotype has arrived? They are comparing found DNA with information from 10 previously identified species of aphids, including several Russian wheat aphid relatives. With the 10 DNA patterns - or barcodes - available, should a new biotype arrive the researchers should be able to identify it quickly. Their research was published in a recent edition of the Annals of the Entomological Society of America.