MSU Urban IPM Alerts

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. 

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)

Blister beetles have been aggregating and causing defoliation on trees and shrubs in yards and gardens.

See this link for more information 

Blister Beetles in the Yard and Garden - MSU Extension IPM Program | Montana State University

See this link for a printable pdf

Blister Beetles in the Yard and Garden - MSU Extension IPM Program | Montana State University

With our hot and dry weather, thrips populations are increasing on many of our vegetables and flowers. Thrips are small, yellowish insects that reside on the undersides of the leaves, and the pest thrips that we have puncture the cells on the leaf surface to drink or suck plant juices.

See this link for more information and for a printable pdf Thrips on Vegetables and Flowers - MSU Extension IPM Program | Montana State University

The MSU Extension Urban Integrated Pest Management Program is hosting it’s 2021 Turf to Trees workshop in Bozeman, Montana, on August 25th, 2021. In this one-day workshop (8:30 am to 4:00 pm) we will focus on topics that are essential and beneficial for green industry professionals, MSU Extension agents, and other horticulture professionals. Topics include, but are not limited to, pollinator health, the challenges of nutrient management for turf and trees, turf alternatives, diseases of woody ornamentals, sustainable landscapes, and tree trends for Montana. We will offer a combination of hands-on training, presentations, and time for questions and discussions. Continuing education credits will be available. Enrollment is limited to 25 participants. A registration fee of $65 will be charged per person and includes lunch, snacks, and refreshments. Please register by August 20, 2021.

Please open the following link to register for this workshop: https://payment.msuextension.org/product/EB27B8BD-155D-011A-017DC98565FC0FA5

For questions, please contact Eva Grimme at eva.grimme@montana.edu or 406-994-5150.

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)

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.

https://ipm.montana.edu/entomology/resources/social_wasps_in_montana_final.pdf

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

Commonly referred to as “the worm in my apple,” codling moths are the primary insect pest of apple and pear in Montana. The adult codling moth typically emerges during apple bloom across the state, which can help growers and homeowners time chemical controls.

There are several options for managing codling moth in backyard plantings. Chemical controls are applied after petal fall and should never be applied during bloom when risk to harming pollinators is high.

See the link to this printable fact sheet for more information (ADA Compliant):

https://ipm.montana.edu/documents/entomology/ent-fact-sheets-2020-2021/2021_insect_fact_sheet_codling_moth_final.pdf

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)