[3.0011] FURTHER OBSERVATIONS ON "FALSE BROODS" OF COLIAS EURYTHEME IN CENTRAL NEW YORK (LEPIDOPTERA: PIERIDAE) 1 ARTHUR M.SHAPIRO 2 . 3 The alfalfa caterpillar or orange sulphur butterfly, Colias eury theme Bois-duval, invaded the northeastern United States from the south and west in the late 1920's, establishing itself within a few years (Clark and Clark, 195 1 ; Gerould 1946). In this part of its range it regularly produces "false broods" of fresh butterflies in November and December (Shapiro 1962, 1968). In 1961 alone, such flights were reported from Toronto, Ont. (Nov. 11); Frankfort, Ky. and and Chicago, 111. (last week of November); Knoxville, Tenn., Baltimore, Md., and Philadelphia, Pa. (first week of December) (Lepidopterists' Society, 1962, and various authors in lift.). They probably originate from pupae whose develop-ment had been arrested by cold; in the laboratory, such pupae may resume development and eclose rapidly under improved thermal conditions, at least for up lo four weeks (Shapiro, 1968). This hypothesis is supported by an emergence at Ithaca, New York, reported below. November 23, 1968 Record. Central New York records indicate that Colias flight activity usually ends at the beginning of November, roughly four weeks after the first frost. This cutoff probably results from worsening weath-er which prevents eclosion and gradually kills off the uneclosed pupae. Collect-ing at Ithaca, J. Keji took or saw his last C. eury theme on the following dates: Nov. 15, 1949; Nov. 7, 1950; Oct. 26, 1951; Oct. 22, 1952. My last dates for 1966-1969 are Oct. 27; Nov. 12; Nov. 23, and Nov. 13 respectively. The 1968 1 Accepted for publication February 7, 1970. 2 Department of Entomology and Limnology, Cornell University, Ithaca, New York 14850. 3 This research was supported in part by National Science Foundation grant GB 7757 (Environmental Biology). En t. News, 81 : 73-77, 1970 73
BioStor
