The Brown Marmorated Stink Bug

By Everett Brazil III

The stink bug family has long plagued agricultural producers across the state, attacking crops like soybeans and cotton and reducing yields as they feed on the plants. That family now has one more member in the state, the brown marmorated stink bug (BMSB), and Oklahoma State University (OSU) Extension researchers are now on guard to monitor the insect to prevent it from becoming a bigger problem.

There are an estimated 35 species of stink bugs in the United States, with about five already calling Oklahoma home. They range in color and have a pentagon, or shield appearance. They also have piercing and sucking mouth parts, which they use to feed on the plants’ flesh and seeds, leading to yield loss in some circumstances.

“In soybeans, they can cause greening – the plant stays green. If they feed on a sorghum seed, it can cause abortion of the seed on the head as they are feeding,” said Tom Royer, OSU Integrated Pest Management coordinator. “They can cause a lot of damage if numbers are large enough.”
The BMSB is new to the state. A native of Asia, it was first discovered in the United States in 1998 and has now been discovered in more than 40 states.

The BMSB has the same distinctive shield shape of other stink bug species, with distinctive marks and colorations. It features white and black bands on the antennae, as well as along the outer edges of the abdomen.

The female goes through several reproductive cycles each year, laying clusters of about 25 green-colored eggs on the undersides of leaves, which turn white just before hatching. The larva goes through five stages over about 538 days, with temperatures between 57-97 degrees, and 32-35 days above 86 degrees.

What sets the BMSB apart from other stink bugs is that it can feed on more than 100 agricultural and horticultural crops, including fruit such as grapes, apples and peaches, garden plants like peppers, tomatoes and eggplants and agricultural crops like corn, sorghum and soybeans.

It also has a tendency to overwinter in homes and businesses, making it a pest to humans, as well.

“This insect is particularly nasty, because it has a wild pallet for preferred host plants – fruits, vegetables, hemp,” said Eric Rebek, OSU Horticultural Entomology Extension specialist.

“On top of that, it is a home invader. It’ll invade people’s homes, looking for a place to spend the winter in a secluded spot.”

Although it has been a problem across the country for many years, it has only been found in  handful of locations in Oklahoma – near Edmond, in Oklahoma County, Guthrie, in Logan County and Stillwater, in Payne County.

Due to the risk presented by a large number of plant hosts, the OSU Cooperative Extension Service is teaming with the USDA-Animal and Plant Health Inspection Service and the Oklahoma Department of Agriculture, Food and Forestry to create a plan to monitor the pest in the state and find ways to control it and prevent it from becoming a problem. That will involve trapping to determine where it is and spraying if needed.

“We‘re just at the beginning stage of trying to determine where the BMSB is,” Rebek said. “We’re going to start setting up traps for monitoring the insect, and see where it is in the state.”

Producers unsure of what species they have in the field should contact their county extension office for verification. If it is determined to be a BMSB, the producer should begin scouting and monitoring it, and it can easily be controlled through insecticide.

“There is no need to spray unless they have a problem with BMSB. We need to get confirmation they have it,” Rebek said. “There are insecticides, and they are primarily the route we’ll have to go to manage them—anything that is labeled for stink bugs, in general, broad-spectrum control insecticide.”
The three agencies are working together on the long-term research and management project to help producers identify and control the insect to prevent widespread damage to crops and other ornamentals.

“We have to figure out where it is, how much of an impact it is going to  have in the state, and we have to make people aware that it is here, and it is a threat,” Rebek said.

Read more great stories in the March 2020 issue of Oklahoma Farm & Ranch.