The spongy moth (lymantria dispar) is a non-native, foliage eating insect that threatens deciduous trees and impacts humans. It is considered one of the 100 most destructive invasive species worldwide. Originally from Europe and Asia, spongy moths made their debut in the Massachusetts in 1869 in an unsuccessful attempt to introduce silk production to the US. They complete one generation in a full year with a life cycle that consists of four stages:

• Egg: Females lay eggs in masses of 500-1000 in August. The egg masses are beige with velvety texture and spongy consistency.
• Larva (caterpillar): The larval stage typically lasts about 7 weeks. Larvae are most active during May and June. The caterpillars partially or entirely strip trees of their leaves. They prefer oaks, especially white and chestnut. But they’ll also eat alder, aspen, basswood, birch, hawthorn and willow trees.
• Pupa (Cocoon): After feeding and accumulating far, the larvae pupate.
• Adult (moth): The adult emerges from the pupa and reproduces

If you have damaged, compromised, or beloved trees in your landscape, be prepared to treat those trees early if spongy moth injury is expected. Talk to an arborist about applying a well-timed insecticide treatment. Also, consider adding a tree band in late May. These trap spongy moth caterpillars as they hike up and down a tree. Don’t forget to fertilize the tree to improve its ability to recover from spongy moth damage. And make sure to water your tree on dry days to prevent any added stress from drought.

Dr. Clive Jones is a terrestrial ecologist with expertise in biodiversity and environmental management. Working with the Cary Institute of Ecosystem Studies in Millbrook, NY, he joined the Nature Calls: Conversations from the Hudson Valley to talk about the recent outbreaks of spongy moths in the area. Clive has spent much of his career studying how organisms physically modify the non-living environment and the consequences for those species, other species and ecological processes. He has also contributed to understanding complex interaction webs in oak forests that connect oaks and acorns with insect outbreaks like spongy moth. He joins Dr. Charles Canham, another senior scientist at the Cary Institute who specializes in forest ecology and management.

We hope you find this conversation and interesting as we did.

Hosts: Jean Thomas and Teresa Golden

Guests: Clive Jones and Charles Canham

Photo by: Teresa Golden

Production Support: Linda Aydlett, Deven Connelly, Teresa Golden, Xandra Powers, Annie Scibienski, Robin Smith

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