Winter Moth is an invasive pest that causes severe defoliation and mortality in hardwood trees. The larvae begin feeding in early Spring on developing leaves with severe infestations causing noticeable tree defoliation. In June, they drop to the ground to pupate in the soil until the fall. You will start to notice adult Winter moths soon as they are generally active from November through January.
Early detection is difficult, as the first instar larvae begin feeding while the pre-formed leaf is still in the bud. The first symptoms will be visible after buds break and leaves unfurl to reveal small feeding holes in the leaves. At this point, the larvae are still generally too small to be seen. In early spring, the feeding damage on the leaf will become more obvious and the caterpillars may grow to a visible size. Generally, the best seasons for injection are fall and spring, as uptake occurs when trees are transpiring. The environmental conditions that favor uptake are adequate soil moisture and relatively high humidity.
Treatment with ACE-jet
A well-timed injection of ACE-jet should be applied when the larvae are actively feeding. ACE-jet is compatible with MIN-jet Iron for a 2-in-1 application of insect control and nutrition. ACE-jet moves quickly and easily to the leaves, providing rapid treatment.
Use ACE-jet in early spring, before buds break, when leaf injury first appears, or when caterpillars are first observed. One application is sufficient to control Winter Moth. ACE-jet remains active to protect the tree canopy for approximately 3 to 5 weeks. Monitor trees to determine the need for a repeat treatment.
Treatment with TREE-äge®
Another option is to treat with an injection of TREE-äge or TREE-äge G4, which can control Winter Moth for up to two years. TREE-äge and G4 may work more slowly through the tree’s vascular system but will have a longer residual protection time than ACE-jet, making it ideal for multi-season protection. You will still want to monitor the tree’s overall health to see if reapplication is necessary. TREE-äge can be injected as long as the soil temperature is above 40 degrees F and below 90 degrees F.
The AzaSol® Option
OMRI listed AzaSol may be used as a soil drench, bark spray, or chemigation formula. AzaSol is not trunk-injected like ACE-jet and TREE-äge, meaning it may have to be applied more frequently to maintain control.
Tree health will also affect treatment efficacy, so assess tree health prior to treating. Do you have questions about treatment? Click here to find a service provider in your area.
©2017 Arborjet, Inc. Important: Always read and follow label instructions. Some crop protection products may not be registered for sale or use in all states or counties. Please check with your state or local extension service to ensure registration status. TREE-äge Insecticide is a Restricted Use Pesticide and must only be sold to and used by a state certified applicator or by persons under their direct supervision. TREE-äge is a registered trademark of Arborjet, Inc.