NMSU researchers studying new invasive pest
New Mexico State UniversityA new invasive pest – a stink bug called Bagrada hilaris. Brassica crops in New Mexico are in danger of attack from a new invasive pest – a stink bug called Bagrada hilaris, which is currently spreading through the Southern part of the United States.
Researchers from New Mexico State University have joined others from California and Arizona to determine ways to control this insect, which could devastate some of the niche-market crops raised by New Mexico’s small-scale and organic growers.
“The Bagrada bug was first found in New Mexico in 2010 in Las Cruces and has since migrated as far north as Santa Fe County,” said Tessa Grasswitz, NMSU Extension integrated pest management specialist and the U.S. Department of Agriculture’s state IPM coordinator. “This insect is native to southern Africa and has recently spread to parts of southern Europe and Asia, becoming a serious problem in India and elsewhere.”
It mainly attacks crops in the brassica family, which includes various Asian greens, such as bok choy, as well as mustard greens, cabbage, cauliflower and broccoli. Grasswitz’s research at the Agricultural Science Center at Los Lunas is among the first in the nation to address management tactics for this pest in organic growing systems.
“Until now, this has been a neglected area of research, because in California and Arizona, where the insect was first found, the main concern has been to protect large-scale conventionally grown brassica crops,” Grasswitz said.
“This insect has sucking mouth parts, which it uses to suck nutrients from the plant,” she said. “While feeding, it also injects a toxin that causes affected leaves to take on a scorched appearance, eventually turning brown and dying
In the main vegetable growing areas of California and Arizona, growers struggle with establishment of their plants because the pest can kill the emerging seedlings.
“Some of these commercial growers have been spraying with various conventional insecticides every three days for three weeks during the establishment phase of the crop to get a stand,” she said. “For organic growers, it’s much more problematic, because organic insecticides are not as potent as conventional products. So dealing with Bagrada bug is a real issue for organic producers.”
Grasswitz is trying to develop integrated pest management strategies for organic growers to use against the Bagrada bug. These tactics include determining the insect’s host plant preferences in order to develop a trap-cropping system, assessing the impact of native predators and parasites and testing various organic insecticides.