Spongy Moths Will be Hatching Soon!
Jingjing Yin, CAAHP Commercial Horticulture Educator
I still remember last year, when Spongy Moth (formerly called Gypsy Moth) caterpillars turned trees and bushes into brown skeletons, leaving an inundation of poop in their wake.
The “Growing Degree Days” (GDD) is a very useful tool for insect pest control of landscape plants, as a measure of accumulated heat calculated by subtracting 50 degrees from the average daily temperature. Egg hatch for Spongy Moth occurs roughly between 90 and 100 GDDs. Today’s GDD in Voorheesville is 82 and will reach 90-100 next week. That means it’s time to watch caterpillar development closely.
Once hatched, caterpillars begin dispersing to feed on trees. Be prepared to apply Bacillus thuringiensis kurstaki (Btk) while caterpillars are still young (when they are between ¼ – ¾ inch in length). Control is best when these moths are still small.
For more control information for Spongy Moth: http://idl.entomology.cornell.edu/wp-content/uploads/Gypsy-Moth.pdf
