RALEIGH – The N.C. Department of Agriculture and Consumer Services is hosting a public discussion of proposed treatments of the destructive spongy moth in Dare and Currituck counties after seeing an increase in reproducing populations from 2021 to 2022. Spongy moth, (Lymantria dispar) formerly known as gypsy moth, is an invasive insect that can cause tree defoliation and tree mortality.
The meeting will be held Friday, Feb. 24, from 5:30 to 7 p.m. at the Kitty Hawk Town Hall, 101 Veterans Memorial Drive, Kitty Hawk. Staff with the NCDA&CS Plant Industry Division will be available to answer questions, take comments and provide information about the spongy moth lifecycle, problems associated with infestations, available management methods, and proposed treatment options.
Treatments are proposed for the following areas within Currituck and Dare counties:
• Kitty Hawk
• Kill Devil Hills
• Nags Head
• Oregon Inlet
The proposed treatment blocks can be found online at: www.ncagr.gov/plantindustry/plant/entomology/ProposedGypsyMothTreatments.htm, which features additional information and an option to submit a public comment or request email/text notifications about treatment dates. Interested parties can type their addresses into the search bar of a map on this page to see if they reside in one of the proposed treatment blocks.
While open to anyone, the discussion will be focused toward residents of and near the areas listed above, which have been identified as having spongy moth infestations and have proposed treatment areas.
Spongy moth control has been an ongoing effort in the United States since 1869. NCDA&CS is working with other states with infestations through the Slow the Spread Foundation and with other state and federal partners to slow the spread of spongy moth into uninfested areas of the country and has addressed spot introductions of the spongy moth across North Carolina since the 1970s.
The impact of spongy moth infestation varies from year to year. The visible signs of leaf loss, tree death and spongy moth caterpillar swarms can range from barely noticeable to devastating depending on how many spongy moths are in the immediate area, how healthy the trees in the area were to begin with, and other factors.
“Spongy moths begin life each spring as spongy moth caterpillars, and like the book the ‘Hungry Hungry Caterpillar,’ they cause the most damage to our forests through their enormous appetite,” said Sara Lalk, NCDA&CS Forest Health Research Operations Manager. “These caterpillars feed on many tree species but prefer hardwoods like oaks. If a swarm of spongy moth caterpillars eat all the leaves off hardwood trees for more than two years in a row, the ones in poor health may die. Healthy trees will regrow their leaves later in the summer, but that takes away from energy reserves they use for growing leaves in the following spring. When healthy trees use these energy reserves it reduces their ability to defend against future feeding or other stress.”
In the Corolla area, 60 male moths were trapped in 2022, up from 25 in 2021. In the Kitty Hawk area that includes Kills Devil Hills and Nags Head, 161 male moths were trapped in 2022, up significantly from 35 in 2021. In the Oregon Inlet area, 63 male moths were trapped in 2022, up from 12. And in the Roanoke Island area, 38 male moths were trapped in 2022, up from 13 the previous year.
Chronic stress on trees is the most damaging result of spongy moth caterpillar feeding. Chronically stressed trees are more susceptible to be attacked by other pests such as wood-boring beetles and decay fungi. Older spongy moth caterpillars may attack conifer species such as pines, which can be killed within a single year. The economic burden of a severe spongy moth outbreak can be great when property owners are faced with large, dead trees that must be removed.
Spongy moth caterpillars can also be a general nuisance. In heavily infested areas, spongy moth caterpillars may swarm on driveways, sidewalks, outdoor furniture, or in pools or homes. Summer leaf canopy loss due to their feeding can affect parks and otherwise scenic areas. Some people are allergic to the tiny hairs shed by spongy moth caterpillars, which can cause an itchy red rash or respiratory symptoms.
Options for dealing with spongy moth infestations include aerial spraying of a spongy moth mating disruptor or a naturally occurring bacteria. All proposed treatments in 2023 use the mating disruptor Splat GM-O, which is an organic product containing the naturally occurring female spongy moth pheromone. The presence of this pheromone makes it harder for male spongy moths to follow the natural pheromone scent trails released by female spongy moths in the area. This decreases mating success and reduces the spongy moth population for the following year. The pheromone is not harmful to humans, animals or plants, and it will not affect other insect species.
To submit comments or request future notifications, residents will need the name of the proposed treatment area found in the block descriptions at www.ncagr.gov/plantindustry/plant/entomology/ProposedGypsyMothTreatments.htm. For more information or questions, contact Lalk at 919-707-3730 or 984-867-6127.
–Sara Lalk, NCDA&CS