Some new developments to report after a conversation with Joseph Zoltowski, Director of the New Jersey Department of Agriculture’s Division of Plant Industry:
- the aerial survey of gypsy moth defoliation will be completed within a week or so;
- Vernon Township has filed a letter with the Division requesting a fall ground survey of gypsy moth egg masses;
- this ground survey is the first step in determining/predicting gypsy moth problems in 2016. The number of egg masses found per acre determines whether aerial spraying would be recommended;
- it is likely that the dry spring prevented the emergence of Entomophaga maimaiga (gypsy moth fungus), and that the recent rains have permitted the fungus to expand, causing the deaths of the caterpillars (many are visible on the trunks of trees);
- the fungus spreads by spores passed from caterpillar to caterpillar and deposited on tree bark, limbs and in soils;the emergence of the fungus is likely to reduce the number of detectable gypsy moth egg masses in the fall, thereby undermining plans for aerial spraying;
The Shelton, CT Herald published a report June 25th on the emergence there of Entomophaga maimaiga after a dry spring and the observed mortality of the caterpillars. Like our area, Shelton was not expected to have a gypsy moth problem this year based on the aerial surveys last fall. And like our area, it seems the hot, dry spring suppressed the gypsy moth fungus allowing the caterpillars to take hold.
Need more information about gypsy moths? Try this publication from the University of Maryland’s Cooperation Extension (thanks to Bob Reffelt for the link).
The bottom line? Widespread emergence of the fungus will kill the caterpillars before they have a chance to become moths and reproduce, tree defoliation will be reduced, trees already damaged will have a chance to refoliate, the number of egg masses found in the fall will be lower, and aerial spraying next spring may not be necessary.
Jack McLaughlin
General Manager
