Wednesday, May 9, 2012

Fall Cankerworm

Fall Cankerworm, Alsophila pometaria (family Geometridae, the loopers, inchworms, and spanworms).  The name is a bit confusing since this caterpillar is active in the spring.  The "fall" part of the name refers to the time of the year when the adult moth is active.  There is another caterpillar called the Spring Cankerworm, with both the caterpillar and adult moth active in the spring.
The Fall Caterpillar is highly variable in coloration.  One way to tell it's an Fall Cankerworm is to look for the extra half of a proleg (not very visible in my pictures).  Caterpillars in the Geometridae usually only have two prolegs, as opposed to the typical five found in other caterpillars