MSU Urban IPM Alerts

Fall - we associate this time of year with an array of vibrant colors on our deciduous trees. However, the yellowing of evergreen trees might cause some concern. Every fall, the inner needles of evergreens start to turn yellow and are dropped over time. This is a natural process known as seasonal needle drop. Please see more information in the attached alert document.

Sincerely,

Eva Grimme

Grasshoppers continue to be an issue for yards and gardens for several areas in Montana, which will last into the fall. Management is very challenging, though some options are available. Consider focusing on the most vulnerable trees and plants for management (and those of importance). See the alert for more information.

After an early cold snap this past September in addition to a tough winter, seeing signs of stress and chlorosis in trees is prevalent in Montana landscapes this summer. Stress in trees can appear as premature fall coloration, branch/crown dieback, curling/wilting of leaves, etc. Chlorosis is a change in leaf coloration (yellowing, early fall coloration, dark green veins, eventual browning of leaf edges, etc.) that is often brought about by a nutrient deficiency. The most common nutrient deficiency in Montana landscapes is due to insufficient iron or nitrogen uptake. Stress and chlorosis can often compound on each other, further impacting tree vigor.

Please contact Abi Saeed (406-994-6523 or abiya.saeed@montana.edu) for questions and recommendations.

Montana has several home-invading weevils that come into our homes starting in April and
through November. They are harmless to humans and structures.

There has been a lot of press about the Asian giant hornet, Vespa mandarinia, aka the murder hornet. It is not known to be in Montana at this time. Two sightings have been confirmed in Whatcom County, Washington in Dec 2019 and in British Columbia in the fall of 2019. See this fact sheet/alert from Alyssa Piccolomini from the Montana Department of Agriculture.