Gypsy Moth Infestation

This summer, the campus grounds have been impacted by a heavy infestation of Gypsy Moths. The moths are currently in their adult stage and can be readily observed fluttering around the main entrance to Dempsey Hall, and other campus facilities.

Efforts will be taken to address this infestation. In the fall, the campus grounds department in conjunction with the Oshkosh City Forester will be spraying the gypsy moth egg masses with an oil that is designed to suffocate the eggs.  Next spring, burlap bags will be tied around the bases of many affected trees, in an effort to disrupt the travel of some of the larvae.  Although not yet confirmed, the Winnebago County may also spray the campus and surrounding community with a widely used and safe biological pesticide such as Bacillus thuringiensis (Bt).   It is our hope that the combination of these efforts will significantly reduce the impact of this pest next summer.

I would encourage anyone who hasn't seen the gypsy moths to talk a walk by the front entrance of Dempsey (on Algoma Blvd.).   It is a great example of an invasive species, and may help you understand why the campus, city, county and state are reacting so strongly.

And it all started a century ago with a scheme for the US to break into the Chinese silk trade by breeding an alternative to the silkworm moth that could eat a more varied diet of tree leaves ... in an age that couldn't predict the invention of nylon ...

BT is a spray of bacteria that has a toxin that primarily acts on moths and butterflies, attacking their stomach lining.  It has been approved for decades as the preferred method to stop/slow gypsy moth infestations.  The harmful effects are mostly to other butterflies and moths, and some insects on land and water.  Human exposure is not considered a problem (our stomach lining is very different from a caterpillar's), but they usually send out warnings and try to spray when there are few people around, mostly to avoid the panic some people may feel when a plane flies low overhead and a white rain falls.

The same toxin is now genetically engineered into about 2/3rds of the corn grown in the US (to discourage the corn-borer moth caterpillars).  Even though that corn is only approved for  non-human uses (animal feed, ethanol), the gene and (therefore, probably the toxin) can be found in practically all food corn products sold in the US, except for some labeled "no GMO".   So there is a very large, non-voluntary experiment going on today on the effects of low, sustained, oral doses of Bt toxin.  Results are due in a few decades.

Mike Lizotte

Further reading:

Gypsy Moth (USDA Forest Service FIDL#162)

Gypsy Moth (Wikipedia)

Controlling the Gypsy Moth with BT (Ohio State Univ.)