This well known species is frequently noticed by field naturalists other thar entomologists because of its conspicuous habit of covering bird cherry bushes with large webs of silk enclosing large sibling groups of caterpillars. In this part of the country, where Prunus padus is a common component of our woodlands, infestations become so numerous as to cause complete defoliation, bushes appearing as in winter except for the covering of silk. Fortunately trees do not seem to suffer any long term damage and begin to produce a second coating of leaves as soon as the caterpillars begin to pupate. The moth is always abundant wherever bird cherry grows.