Spring Cankerworm (Paleacrita vernata) - Adult moths are drab gray, delicate with green markings. Males have a wingspread of about 1 inch while the females are wingless. Cankerworms, like other members of this family, often are called “inchworms” because of the way they crawl. They arch their back into a loop, anchor the hind legs and extend the front to move ahead. The spring cankerworm, Paleacrata vernata (Peck), has two pairs of prolegs on the abdomen, while the fall cankerworm, Alsophila pometaria (Harris), has three pairs of abdominal prolegs. Larvae grow to 1 inch, are variable in color and marked predominantly with green, brown and pale yellow longitudinal stripes.