Not happy to see this incredibly destructive pest clinging to a window pane!!!
Gypsy moth caterpillars defoliate trees, shrubs and hardwood forests thereby weakening their hosts and leaving them susceptible to disease and other pests. Apparently, Gypsy Moth outbreaks come in 7-10 year cycles and last for 2-3 years. The last outbreak here was about 5 years ago and in spite of aggressive multiple pest control measures at that time it looks like a new outbreak is on the horizon far earlier than expected. According to the city's urban forestry website, plans are currently being made for aerial spraying and other pest control measures to occur next year.