Intrepid (methoxyfenozide) endangered species restrictions for Michigan

Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.

The EPA recently issued an endangered species bulletin for Intrepid insecticide to protect Karner blue butterfly in several Michigan counties. Here are the details pertinent to Michigan.

Karner blue butterfly

This butterfly, listed in 1992 as endangered, is found around the Great Lakes region in Indiana, Michigan, Minnesota, New York, Ohio and especially Wisconsin. Karner blue butterfly larvae (caterpillars) feed exclusively on wild lupine, which grows in specific habitats, oak and oak-pine barrens and sand prairie. Much of this habitat has been lost, so Karner blue butterfly populations are very low.

Intrepid (methoxyfenozide)

Intrepid is a relatively new product from Dow Agrosciences with a unique chemistry. It is an insect growth regulator that selectively kills caterpillars such as armyworm and loopers. This explains why there is a concern with spraying near Karner blue butterfly habitat.

Intrepid is registered on many crops

Field crops include corn (field, seed), soybean, sugarbeet, spearmint and peppermint.

Vegetable/ fruit crops important to Michigan include: Cole crops such as broccoli, Brussel sprouts, cabbage, cauliflower, collards, mustard greens. Leafy vegetables such as celery, lettuce, rhubarb, spinach, chard. Fruiting vegetables such as eggplant, pepper, tomato. Cucurbit vegetables such as cucumber, honeydew, squash, watermelon, zucchini. Legume vegetables such as various kinds of peas and succulent beans. Root and tuber vegetables such as carrots, beets, radish, rutabaga, turnip. Artichoke. Sweet corn. Grapes, strawberry, apple, cherry, peaches, pear, plums.

Counties affected

Allegan, Monroe, Montcalm, Muskegon, Newaygo, Oceana: If you are using Intrepid and farm in one of these six counties, this bulletin applies to you. These counties are also listed on the Intrepid label.

What does the bulletin say?

In the counties listed above, do not apply Intrepid “within one mile of sandy habitats that support wild lupine plants.”

The key question…

How do you know you are within a mile of lupine habitat? I don’t know! I guess you just have to know where the oak barrens are in your neighborhood. For some endangered animals, EPA or the Fisheries and Wildlife Service provide maps so you can determine if you are near critical habitat. Maps are usually not provided for endangered insects because unfortunately people collect and sell them for lots of cash (especially butterflies). Revealing the location of habitat simply opens the site up to be over-collected by these destructive goofballs.

Dr. DiFonzo’s work is funded in part by MSU‘s AgBioResearch.

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