by Kate Shunney

Agriculture and forestry officials have said spongy moths – known previously as gypsy moths – are likely to show heavy impacts in parts of forested Morgan County and other areas of West Virginia this spring.

The West Virginia Department of Agriculture (WVDA), in cooperation with the United States Department of Agriculture- Forest Service (USDA-FS), is proposing to perform aerial treatment of more than 2,000 acres in Morgan County to impact young caterpillars this spring.

State officials said sprays will be used for the purpose of “reducing significant impacts to forested lands within West Virginia caused by the Lymantria dispar (gypsy moth).”

The WVDA proposes to treat these acres under the WVDA Cooperative State- County-Landowner (CSCL) Suppression Program.

They are seeking public comment from the areas that will see this aerial treatment take place.

Agriculture officials say without treatment, the moth infestations in the county “will reach high enough levels to cause defoliation and possible tree mortality.”

“Large numbers of caterpillars are expected in the 2023 treatment area. It is likely many already stressed trees will not be able to withstand an additional heavy defoliation and will die. Water quality, recreation experiences, wildlife habitat, and timber production could all be negatively affected. Excessive mortality will also reduce visual quality,” said WVDA officials in a public notice about the treatment plan.

“The WVDA anticipates the possibility of significant defoliation in 2023 because of an increase in the Lymantria dispar population in areas of Morgan County,” said agriculture officials.

Approximately 2,681 acres of forest land are proposed for treatment in Morgan County. The WVDA will treat approximately 2,681 acres with either Mimic 2LV or Foray 48B under the CSCL Program.

Areas will be treated during the month of May. Specific treatment dates will depend on weather conditions and the stage of development of the Lymantria dispar, said agriculture officials.

Landowners in the cooperative spongy moth program signed a contract with the West Virginia Department of Agriculture and paid a deposit confirming the requested treatment for their Lymantria dispar problem. Landowners select the spray material to be used on their property and verify their property boundaries as part of the program.

Areas with 500 egg masses per acre (em/ac) or higher were designated for possible treatment on properties considered wooded residential, wooded recreational, or non-residential forested land.

Treatment will consist of one application of a specific control agent. These agents are a bacterium known as Foray 48B (Btk), which affects young caterpillars with minimum effects on other insects and animals or Tebufenozide (Mimic), which has a very low toxicity to all mammals and aquatic species.

The WVDA has completed consultation with the WV Division of Natural Resources Wildlife Resources Biologist concerning the presence of any presence of rare, threatened, or endangered species (RTE) within the proposed treatment area. No impact to RTE species is anticipated. The WVDA is in the final stage of consultation with the United States Department of the Interior Fish and Wildlife Service and the United States Department of Agriculture Forest Service concerning RTE species.

Humans advance spread

The young Lymantria dispar caterpillars are spread by the wind, which blows the silken threads they exude, creating a parachute effect. Movement by this mechanism tends to be slow.

Man, however, has sped up the process considerably, by unwittingly transporting the pest as eggs or caterpillars on firewood, RVs, campers, and other vehicles.

The WVDA cautions against the transport of firewood into or out of the state because pests such as the Lymantria dispar, hemlock woolly adelgid, emerald ash borer, spotted lanternfly, and other invasive insects may be in or on the wood.

These non-native pests have potentially devastating economic effects. Owners of RVs and campers are asked to thoroughly inspect and wash their equipment before moving it. Even with all of these precautions, the Lymantria dispar has and will continue to spread, leaving site specific treatments as the only way to prevent population explosions and resulting tree mortality.

The Lymantria dispar fungus, Entomophaga maimaiga, though present, did not prevent the deposit of large, healthy, and viable egg masses in 2022.

Public comment sought

The WVDA will immediately begin solicitation of public comment on the areas proposed for treatment to reduce the devastating effect on West Virginia’s Forest by the Lymantria dispar. The WVDA will use this input to identify any significant issues related to the proposed project and to develop a range of alternatives.

Any comments, concerns, or interest in this proposed project should be submitted in writing to Quentin “Butch” Sayers, Assistant Director or G. Scott Hoffman, GMCS Coordinator, P.O. Box 9, New Creek, WV 26743 or via e-mail to ghoffman@wvda.us no later than April 1, 2023.