Subject: It can’t be a gypsy moth caterpillar!
Location: Long Island, NY, USA
May 28, 2017 5:08 am
Hi. I live on Long Island, in NY. I have scrub oak trees in the front and back of my small yard. Every year we get caterpillars that come down on silk strings and then crawl up my trees and munch on the leaves and poop on the ground. Every single person here is saying that they are gypsy moth caterpillars, and that certainly fits the description, yet nobody bothers to look at them. They do not have double dots going down their backs and none of them are blue. They have single red dots going down their backs and some tiny yellow dots in pairs and on their heads and tails.
Please, can you help me to correctly identify these caterpillars? Thank you!!!
Our first reaction was that they act like Gypsy Moth Caterpillars and they resemble Gypsy Moth Caterpillars, but they are different. We then did a web search of Caterpillars and Long Island and found the Alternative Earth Care Tree & Lawn Systems site and the pictured Gypsy Moth Caterpillar looks exactly like the image you submitted. This brings up several possibilities in our mind, and demands additional research. First is that there is a Long Island variation on the Gypsy Moth Caterpillar and second is that perhaps this is an earlier instar than that typically shown. Caterpillars molt five times and their appearance often changes startlingly, so different instars might appear to be different species. The site states: “The caterpillar larvae are about ¼” long and are black in color. As they grow they develop black hairs and colored spots and can eventually grow to 2 ½” long.” Since it is just the end of May, the early instar possibility seems most valid as the caterpillars feed into mid-summer. This BugGuide image appears to be a transitional phase between your individual and the more typically pictured Gypsy Moth Caterpillar. This BugGuide image from mid May also has coloration similar to your individual, so we are convinced that your individual is indeed a Gypsy Moth Caterpillar. Perhaps you will entertain the thought of sending us an additional image later in the summer when your caterpillars should be maturing and more closely resembling the red and blue spotted appearance generally pictured for Gypsy Moth Caterpillars? BugGuide does state: “‘The larval stage (caterpillar) is hairy, and a mature larva is 50-65 mm long with a yellow and black head. Behind the head on the thorax and abdomen are five pairs of blue spots (tubercles) followed by six pairs of brick red spots.'(from Penn State website) Please note: earlier instars (under about 12mm) do not exhibit the characteristic blue and brick red pairs of tubercles, nor the yellow and black head. Look instead for ‘first thoracic segment with prominent subdorsal warts bearing numerous long setae that makes face look “eared.” ‘(Caterpillars of Eastern Forests). ”