Hobo spiders_central and western Montana (Horticulture/Urban IPM)

During late summer and early fall, it is normal for spiders to enter buildings and homes. This includes hobo spiders which have long been prevalent in Montana. Common misconceptions about the hobo spider often cause unnecessary concern.

See this link for more information https://ipm.montana.edu/entomology/resources/hobo_spiders.html

See this link for a printable fact sheet (ADA compliant)


Alert Period: 08/05/2021 - 11/30/2021
Submitted By: Lauren Kerzicnik
Herbicide Injury in Home Gardens (Horticulture/Urban IPM)

The Schutter Diagnostic Lab is receiving garden vegetable samples showing symptoms consistent with synthetic auxin, also known as plant growth regulator, herbicide injury. In many of these cases, we suspect carryover of persistent herbicides in newly applied topsoil or garden amendments such as compost and manure. Symptoms include extreme cupping and twisting of leaves, twisting and/or cracking of stems, and general distortion of plant parts. Leaves may feel thicker than normal, and may have veins that look more parallel than usual. Commonly these symptoms are most pronounced on newer growth. These symptoms can come from other sources, including herbicide drift, or insect or disease issues if symptoms are not widespread. Many different broadleaf plants may be affected, but usually most pronounced injury is to tomatoes and potatoes, with peppers, beans, peas, squash, and other vegetables also showing some symptoms. Another clue is a recent application of manure or compost, or a recent load of topsoil being brought in to fill raised bed. There are several MSU Extension publications that cover this issue, including the new brochure called Understanding Herbicide Contaminated Soil Amendments for Greenhouses, Nurseries, and Home Gardens

Alert Period: 07/23/2021 - 10/01/2021
Submitted By: Lesley Orloff
Asian Giant Hornet (a.k.a. Murder Hornet) and Its Look-Alikes (Horticulture/Urban IPM)

Several questions are coming in about the Asian giant hornet (a.k.a. “murder hornet). To date, it has not been detected in Montana. See pictures of the Asian giant hornet and common look-alikes here Asian Giant Hornet and Look-Alikes - MSU Extension IPM Program | Montana State University

A printable pdf is available here Asian Giant Hornet and Look-Alikes (montana.edu)

Alert Period: 07/20/2021 - 09/30/2021
Submitted By: Lauren Kerzicnik
Grasshoppers in the Yard and Garden_Statewide (Horticulture/Urban IPM)

Grasshoppers are becoming an issue around the state. Once grasshoppers are adults and have entered the yard and garden, management is extremely challenging.

See this link for more information and for a printable pdf (ADA compliant). 

Grasshoppers in the Yard and Garden (montana.edu)

Alert Period: 06/10/2021 - 11/01/2021
Submitted By: Lauren Kerzicnik
Social Wasps in Montana_time to put western yellowjacket traps out (Horticulture/Urban IPM)

We have several social wasps in Montana. Except for the Western yellowjacket, social wasps are typically not aggressive unless their nest is disturbed. Most are beneficial and feed on a lot of our garden pests. Our most common wasps are bald-faced hornets, aerial yellowjackets, Western yellowjackets, and paper wasps. It is time to put out traps for western yellowjackets to trap queens.

See this fact sheet for more information.



Alert Period: 05/25/2021 - 10/01/2021
Submitted By: Lauren Kerzicnik
Brown marmorated stink bug_confirmed in Kalispell (Horticulture/Urban IPM)

The invasive brown marmorated stink bug, Halyomorpha halys, was found flying within a car in Kalispell (Flathead Co.) on May 4, 2021. The stink bug was confirmed for the first time in Montana on January 26, 2021 (from inside a home in Billings).

We currently don’t know what impact it might have on our crops, specialty crops, and as a nuisance home invader across the state.

See this link for more information on the stink bug

Brown Marmorated Stink Bug - MSU Extension IPM Program | Montana State University

Alert Period: 05/20/2021 - 11/30/2021
Submitted By: Lauren Kerzicnik
It's Tick Season_Statewide_revised (Horticulture/Urban IPM)

It’s tick season and time to look out for ticks. The Forest Service also released a report about an increase in Colorado tick fever cases (vectored by the Rocky Mountain wood tick) last summer (2020) in the Lolo, Bitterroot, Beaverhead-Deerlodge, and Salmon-Challis National Forests.

See the attached fact sheets for more information on ticks in Montana and the report from the Forest Service.

(revised to include Forest Service report)

Alert Period: 04/07/2021 - 09/30/2021
Submitted By: Lauren Kerzicnik
Alert Documents: