Prepare now for another grasshopper invasion


Believe it or not, volunteers are counting grasshoppers this spring in designated areas throughout Routt County. If we experience another dry spring such as last year, we can expect to be inundated with grasshoppers again this summer.

Therefore, the Routt County Cooperative Extension Office is proactively addressing the problem now while the little critters are immature and not yet consuming vegetation. The office has been collecting signed releases from property owners in designated areas that allows for treating infested areas with insecticide.

The plan is to use a strategy called RAATS (Reduced Area and Agent Treatments). Over large areas, a product called Dimilin will be sprayed from small airplanes. In smaller areas, alternate 20-foot strips of land will be sprayed using a tractor with spray tank.

Dimilin is not a true insecticide, but a growth regulator. It simply doesn't allow the shell of the grasshopper to harden, making it impossible for the insects to reach maturity. Dimilin is as effective as insecticides, provided it is applied when the grasshoppers are immature. One of the benefits of Dimilin is the very low risk to people, wildlife and other beneficial insects such as bees. It can be applied to areas with grazing livestock. Dimilin also costs less per affected acre.

During May and June, volunteers will continue to monitor and count grasshoppers in the area. If heavy infestations are found, those infestations will be treated with the insecticide malathion, provided funds are still available.

According to Extension Agent C.J. Mucklow, "this program has been successful in other grasshopper infestations. However, there is no guarantee that it will be effective here or that all landowners will see a reduction of grasshoppers on their property." It's worth trying, however, in light of the destruction that occurred last year.

Once grasshoppers move into our gardens, our options for controlling them are limited.

A microbial insecticide, known by the trade names Semaspore and NoLo Bait, is only effective against young grasshoppers. This product will take about two weeks to begin taking effect and must be purchased fresh and used right away. The young grasshoppers eat this bait and spread disease to other grasshoppers.

As grasshoppers come into your garden, insecticide treatments will have limited success since there is continual reinvasion by grasshoppers and the product wears off relatively quickly. Insecticides such as acephate (Orthene), carbaryl (Sevin), diazinon and malathion are available at local retailers.

Please read and follow the directions carefully as these products are toxic to beneficial insects such as bees, flies and butterflies. They also leave residue on edible plants that can be harmful to humans. It's best to spray these insecticides at night or early morning when bees, flies and butterflies are less active.

Be on the lookout for the young nymphs this spring so you get the jump on hoppers before they get the jump on you.

Deb Babcock is a Routt County resident and a master gardener through the Colorado State University Cooperative Extension office in Routt County.


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