Burlington County, NJ suffered less tree defoliation by gypsy moth caterpillars during 2008; 66,454 acres of trees were defoliated in 2008 vs. 90,574 acres in 2007. However, New Jersey overall suffered more damage with 339,240 acres defoliated, up from 320,610 acres in 2007. The worst damage seems to have shifted to the northwest, with Suffix County being the hardest hit in 2008. (See map below.)

In Shamong, NJ, the gypsy moth problem was not as bad as in 2007. The Central Record reported that 5,180 acres were defoliated in Shamong in 2008, vs. 9,968 acres in 2007.

Aerial spraying of BT (bacillus thuringiensis) by the township surely provided some benefit. However, the situation was clearly helped by the cold, wet weather in late April and early May. The wet weather allowed the caterpiller's natural enemy, the fungus Entomaphaga Mamaiga to multiply and thrive. It likely killed many, and maybe even most, of the gypsy moth larvae.

Also in 2008, Shamong homeowners did more to fight the gypsy moths. These measures included hiring local pest contractors to spray from the ground, banding trees with duct tape and Tanglefoot, and banding trees with burlap. Some homeowners wrapped trees with burlap sprayed with Eradicoat. Eradicoat contains a pesticide; probably Deltamethrin. Gypsy moths die shortly after coming in contact with the treated burlap.

This year, in addition to using the duct tape, Tanglefoot and burlap methods, we used Eradicoat sprayed on the burlap. What we observed was that once the caterpillers encountered the treated burlap, they became lethargic and sickly. They died shortly thereafter. Larger caterpillers coming down from the tops of trees stopped on the burlap, often crawled under it, and also died. We also observed dead caterpillers in the "inverted V" position, characteristic of their own highly contageous "nucleopolyhedrosis" virus. This years dead could have been the victims of residues of this virus left over from last year. Whether we can figure what to attribute this complete turn around of the war with the gypsy moths or not, the answer probably lies with the fact that whatever got through the first line of defense more than likely got killed by the next. The result for us was that we did not have to bother collecting and destroying gypsy moth caterpillers. Whatever worked, we are celebrating a victory this year as our trees are mostly intact. We also did not have gypsy moth feces raining down on us. And we did not have to wash our cars, porch and deck continually.

New Jersey 2008 Gypsy Moth Tree Defoliation Map

Map from the New Jersey Department of Agriculture