Idaho Targets Japanese Beetle in Caldwell to Protect Agriculture

POCATELLO, Idaho — Idaho agriculture officials are taking aggressive action after five Japanese beetles, a highly destructive invasive pest, were detected in Acequia near Rupert, according to information provided by the Idaho Farm Bureau Foundation.

The Idaho Farm Bureau Federation reports the Japanese beetle, a non-native insect that feeds on more than 300 species of agricultural and ornamental plants, poses a significant threat to Idaho agriculture. In response to the discovery, the Idaho State Department of Agriculture (ISDA) has deployed about 800 traps in the Rupert area to determine the extent of the infestation.

“We take an aggressive approach to make sure we don’t see those numbers boom before we can actually handle the situation,” said Vene Stewart, an ISDA pest survey and detection specialist helping lead eradication efforts.

Stewart said Japanese beetles are not selective feeders.

“They eat about 300 different types of flowering plants. Pretty much anything that flowers, they would love to demolish,” Stewart said.

The ISDA is also conducting eradication efforts in Caldwell and Pocatello. Last year, the department detected 160 Japanese beetles in Caldwell and 12 in Pocatello. Residents in those areas, as well as Acequia, may notice the yellow traps used to monitor the pest’s presence.

“We will be treating all three of those areas this year,” Stewart said.

Caldwell, like Acequia, is located in a major agricultural region. About 700 traps have been placed throughout the Caldwell area.

“The Caldwell infestation isn’t moving at all,” Stewart said. “In fact, where we are finding the beetles is getting to be a smaller and smaller area. You like to see that.”

The department has also placed approximately 550 traps in the Pocatello area.

Stewart said eradication efforts require ongoing monitoring and treatment.

“It’s unfortunately not something that we can just treat one time and assume everything’s going to be (OK) the following year,” she said. “It’s something we’re going to have to keep up on.”

According to a recent University of Idaho study, agriculture accounts for one in every nine jobs in Idaho, 17% of total sales and 12% of the state’s gross domestic product.

ISDA officials have worked to eliminate Japanese beetles wherever they appear in Idaho. About 15 years ago, large numbers of the beetles were detected in the Boise area. Officials say the state’s eradication campaign there resulted in no detections in Boise for several years. According to ISDA officials, the effort became the largest documented Japanese beetle eradication in U.S. history.

“We definitely want to protect our agriculture, especially in Caldwell where it is such an agriculture-(rich) area,” Stewart said. “It’s definitely important to the residents and the farmers out there to make sure that we keep our eye on it and make some progress.”

Stewart said the department’s eradication efforts have received support from farmers, local residents and city officials.

Adult Japanese beetles are about a half-inch long with metallic green bodies and copper-colored wing covers. The insects can skeletonize leaves and leave holes in plants while feeding.

Officials warn that if the beetle were to establish a permanent presence in Idaho, it could lead to reduced crop production, increased pesticide use and potential market restrictions through quarantine measures.

Native to Japan, the beetle was first detected in the United States in 1916 and is now found throughout most states east of the Mississippi River.

Although Idaho has preventative measures in place to reduce the risk of introduction from infested states, ISDA officials believe the beetles still arrive by hitchhiking with people moving from affected areas.