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Holy cow was last summer interesting! All that dry weather contributed to some odd things in the insect world. Beginning in the spring, news of the first insect “plague” spread. Most of these insect “booms” are natural and pretty much harmless but they are a nuisance.

Remember those “inchworms” that descended from the tree tops on thin silken strands? They seemed to be everywhere. These cankerworms and spanworms eat a host of hardwood leaves. The eggs hatch in the tree tops, but after a few weeks of feeding, they drop to the soil to pupate.

To reduce the presence of these insects, you can try applying sticky material around your trees in the spring about a week before the first serious thaw, and again, after the first real killer frost in September. The female moths emerge around these times and crawl up the trees. They are wingless and cannot fly.

The large aspen tortrix also had a good year in 1998. The green larvae have dark heads. Their work was noticed as they ate the fresh leaves out of aspen. The larvae actually hatched in 1997 and spent the winter in spun hideouts. They emerged in the spring of 1998 and began rolling up leaves. Spring of 1998 was good to them and, as a result, many patches of defoliated aspen were reported.

Another real interesting bug was the pale green weevil, an iridescent beetle about 1/8 of an inch long. We see them almost every year but in 1998 there was a bumper crop. These guys feed on aspen, too. Aspen is a favorite food for many insects, as well as birds and mammals. The weevils were found almost everywhere across the Upper Peninsula, in every home, at every picnic, and just about everywhere else. As usual, they are pretty much harmless, but a real nuisance. I even heard a story about a convenience store being closed for a couple hours so the staff could get rid of a population explosion inside the store!

Once the fall came, we all noticed the presence of those delightful ladybugs with the orange body and black spots. Well, they turned into a nightmare as they crunched underfoot everywhere and dive-bombed you while you were watching TV or trying to sleep. These beetles are foreigners; probably stowaways from an Asian freighter on a Gulf of Mexico port around 1988. Over the decade, they have successfully spread north and in 1998 were literally all over the place in the U.P.

Ladybugs are usually known as a gardener’s friend. A single ladybug may eat as many as 300 aphids in its lifetime. This Asian ladybug has the same appetite for soft-bodied insects but its menu is much less selective than the native ladybugs. You’ve probably noticed that they have begun to pop out of the woodwork again. Don’t use insecticides in the house. The beetles will probably crawl back behind the walls to die and the carcasses may then attract even less welcome bugs.

And speaking of Asian invaders, a word about the Asian long-horned beetle is probably a good idea. This woodborer loves maple and has no natural enemies and no known treatments, at this time. And it kills trees, not just lives in them. The potential threat to the U.P. is considerable because our forest types are its favorite food. However, the only known outbreaks have occurred in New York and Chicago. Tree removal, chipping, and burning will probably eliminate this vanguard. The beetles have been found in crating at a number of other sites and were destroyed on site. So, while the threat is significant, there have been no reports in the U.P. and there probably won’t be. But if you’re curious about this gorgeous but nasty beetle, contact the County Extension office or try the Internet at www.aphis.usda.gov/oa/alb/alb.html. There’s also information on the website for the Michigan Society of American Foresters at http://forestry.msu.edu/msaf.

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Bill Cook is an MSU Extension forester providing educational programming for the entire Upper Peninsula. His office is located at the MSU Upper Peninsula Tree Improvement Center near Escanaba. The Center is the headquarters for three MSU Forestry properties in the U.P., with a combined area of about 8,000 acres. He can be reached at cookwi@msu.edu or 906-786-1575.

Prepared by Bill Cook, Forester/Biologist, Michigan State University Extension, 6005 J Road, Escanaba, MI 49829
906-786-1575 (voice), 906-786-9370 (fax), e-mail: cookwi@msu.edu

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By-line should read "Bill Cook, MSU Extension" Please use the article trailer whenever possible.

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Last update of this page was 5 November, 2018