Dr. A: Yellowmargined Leaf Beetle Likes Cool Weather

Clint Thompson Alabama, Pests, Top Posts

Ayanava Majumdar, Extension Professor in Entomology and Plant Pathology at Auburn University, cautions all vegetable producers one insect to be wary of right now is the yellowmargined leaf beetle.

Unlike some insects that thrive only during the summer, or warm conditions, the yellowmargined leaf beetle likes cooler weather and will impact brassica crops.

“It’s a small beetle that when you scout for it, it may drop off the plant. Farmers may miss it and think it’s a caterpillar but it’s actually this leaf beetle that likes the cool weather,” Majumdar said.

“It does a massive amount of damage, not only this time of year, but the population just gets worse in spring. Farmers who already have yellowmargined leaf beetles will probably get worse in spring. We need a timely intervention, chemically or organically speaking, to stop the yellow margined leaf beetle.”

Identification Important

Majumdar said the first step in yellowmargined leaf beetle management is to make sure farmers identify it correctly.

“The beetle and the larva, they feed together on the leaves. They especially love turnips, turnips and napa cabbage. They will tear up the turnips and cabbage at first before moving on to other brassicas,” Majumdar said. “The one thing to remember is BT products … they don’t work against the beetle. It will take care of the caterpillars but not the beetles. Diagnosis is very important before farmers take off with control.”

Another concern that producers need to be mindful is insecticide resistance. Majumdar stresses that growers not overspray, because it could lead to resistance issues.