Winter Moth Control
Winter moth are a non-native pest that has been detected in the Northeast since the early 2000s. The winter moth larvae (caterpillars) feed on the leaves of deciduous trees and shrubs in the spring and can severely defoliate them (eat all the leaves). Some common trees they attack are maple, oak, ash, elm and fruit trees. Multiple years of this heavy defoliation by winter Moth will reduce the health of the trees and can lead to mortality in severe cases. Winter moth larvae are light green with white stripes along both of their sides and about half an inch long when mature. Adult male moths are light brown, and the wingless females are grey.
Winter Moth Pest Control Treatments
The most heavily infested trees may be completely defoliated, and while healthy trees are capable of putting out a second set of leaves, the process puts severe stress on the tree. Research has shown that complete defoliation can reduce the annual growth rate of some oak species by as much as 47%, and successive defoliations can kill branches or entire trees.
The impact of the caterpillars may also be exacerbated by secondary effects such as prolonged, cool springs, which allow the caterpillars to feed longer in the buds; dry years which put trees under additional stress; and infestations of other insects such as bark beetles, fungal parasites, or other moth species.
Here at Hawkes Tree Service we offer several chemical control methods that work exceptionally well against Winter moth caterpillars. Foliar sprays are applied directly to the surface of leaves using a high powered pump and tank system. When the caterpillars ingest the treated leaves, they will be fatally exposed to the product. We have several organic and synthetic products that we recommend for our clients.
Life cycle better explained
Winter moth larvae (caterpillars) emerge from eggs early in the spring when the buds of deciduous trees are beginning to flush, usually in early April. The larvae feed on the buds and the leaves until they reach maturity in early summer when they drop down from the trees and burrow into the soil to pupate (cocoon phase). In November, adult moths emerge from the soil and begin searching for a mate. Batches of eggs are laid on the crevices of tree bark where they are protected for the winter until they hatch the following spring.
Winter Moth Treatment Options
There are two treatment options and timeframes for winter moth. When the adults emerge in November a manual practice of wrapping the trunk of susceptible trees with tape or a sticky substance can catch adult moths looking to mate before they are able to do so. Female winter moths have reduced wings and cannot fly so they crawl up the trunk of trees into the canopy and use pheromones to attract a mate. The sticky surface on trunk can trap the female moths before they can mate, thus reducing the population.
The second treatment option Hawkes Tree Service performs is a chemical treatment in spring when the larvae are feeding on the foliage of trees and shrubs. Systemic trunk and soil injections can be used to protect the tree by injecting a product that works systemically, meaning it is absorbed by the tree and the product is carried up to the leaf tissue where the winter moth are feeding. The larvae ingest the product and die, reducing the damage and threat to your trees. Additionally, foliage sprays using specialized pump and tank equipment can be used to coat the exterior of leaves with products that are fatal when ingested by the larvae. Hawkes Tree Service can spray trees up to 90 feet tall with this system.
Maine Pest Control Guidelines
The State of Maine has strict guidelines for which products and treatment methods may be used for Winter Moth within 250 feet of the mean high water mark. These laws are designed to protect the integrity of marine ecosystems and habitats. Inside this setback zone we recommend individual tree injections. Soil injections use a small volume of product inserted near the base of the tree’s root flares where the fibrous root hairs can absorb it. The systemic product is translocated throughout the tree with other nutrients and delivered to the new tissue in growing leaves.
Trunk injections work in a similar way and use a systemic product as well. In this case, we actually drill a small hole into the root flares of the tree and insert a needle that is connected to a system containing our product. The tree will pull the product in as it does with water and other nutrients and when we are done the tree will compartmentalize the small wounds and quickly heal over.
Every property is a bit different when it comes to treatment methods for Winter Moth. If you would like more information or a free consultation for your property, please contact us or call today at (207) 442-7444.
