Winter Moth Adult is found in Late Fall, Early Winter - Image by umassgreeninfo.org

Winter Moth, an introduced pest causes severe defoliation in hardwood trees.  Winter Moth is appropriately named since adult moths can be active from November through January. Larvae feed early on developing leaves and severe infestations will defoliate trees. In June they drop to the ground to pupate in the soil until fall.  Research has shown 4 consecutive years of defoliation can lead to tree mortality.

Winter Moth Caterpillar is found in the Spring - Image from www.capecodextension.org

Treating Winter Moth

ACE-jet is systemic insecticide used for systemic tree injection

Arborjet recommends a well timed trunk injection using ACE-jet.  Applications can be done with the Tree I.V. or QUIK-jet system.  ACE-jet can be combined with the micro-elements MIN-jet IRON, MIN-jet Calcium and MIN-jet Manganese for a 2 in 1 application.  Micro-nutrients will increase tree health.

Best Time for Treatment

Winter Moth Distribution Map

Generally, the best seasons for trunk injection are fall and spring. Uptake occurs when trees are transpiring. The environmental conditions that favor uptake are moderate temperatures, adequate soil moisture, and high humidity.  Soil temperature should be above 40 degrees for trunk injection.  Tree health will influence uptake time.  A dying tree is a poor candidate for treatment. Use ACE-jet in the spring, when caterpillars or damage first appears.  Timing is critical as ACE-jet will only remain active in the tree for approximately 2-4 weeks.

Treatment Results

Tree I.V. device micro-infuses ACE-jet into the vascular system of trees.

ACE-jet trunk injection in the spring will uptake very quickly and caterpillars will die rapidly. Monitor trees annually to determine the need for a repeat treatment.  Contact any of our service providers for more information.

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