Proposed Btk Bacillus thuringeniensis kurstaki (Btk) is a bacterium that is toxic only to caterpillars. Btk does not adversely affect adult moths and butterflies, nor does it adversely affect other application insects or any organisms that consume the caterpillars. Species January February March April May June July August September October November December
Asian Gypsy Moth eggs young larvae older larvae pupae adult eggs Lymantria dispar asiatica
Western Tiger Swallowtail pupae adults and larvae (multiple broods) pupae Papilio rutulus
White-Lined Sphinx pupae adult eggs larvae adult eggs larvae pupae Hyles lineata
Polyphemus Moth pupae adult eggs larvae pupae Antheraea polyphemus
Monarch Butterfly adult adults and larvae (one or two broods) adult Danaus plexippus
Red Admiral pupae adults and larvae (multiple broods) pupae Vanessa atalanta
Western Skipper young larvae older larvae pupae adult eggs young larvae Ochlodes sylvanoides
Gray Hairstreak pupae adults and larvae (multiple broods) pupae Strymon melinus
Mourningcloak Nymphalis antiopa adult eggs larvae pupae adult
Pepper Moth pupae adult eggs larvae pupae Biston betularia
Garden Tiger Moth larvae pupae adult eggs larvae Arctia caja
Oblique-Banded Leafroller pupae adult eggs larvae adult eggs larvae pupae Choristoneura rosaceana
Thallophaga taylorata pupae adult eggs larvae pupae
Photo credits: Thomas Shahan, Brocken Inaglory, Didier Descouens, Fir0002, HaarFager, Phenology of Butterflies and Moths in Oregon John Flannery, Joseph Berger, Andy Reago, Chrissy McClarren, Chris Hedstrom in relation to Asian Gypsy Moth eradication efforts
Created by Chris Hedstrom, February 2016