| a lus. be OF AGRICULTURE | 
August 1962 SERIAL RECORDS | ARS-33-75 

United States Department of Agriculture 
Agricultural Research Service 
SEX DETERMINATION OF LEPIDOPTEROUS PUPAEL/ 
By B. A. Butt and Eliud Cantu 
Entomology Research. Division 
Sexual characteristics differentiating male from female lepidopterous 
pupae were noted by Jackson (1) and Poulton (2) in the latter half of the 
19th century. This knowledge, however, has only recently been utilized 
in the field of applied entomology. Flaschentrager, Jarczyk, and Hafez 
(3) sexed pupae of Prodenia litura F. in sex attractant studies. Solomon 
(4) sexed pupae of the elm spanworm Ennomos subsignarius (Hubner) in 
investigations on this hardwood forest defoliator. 
Because of currently expanding research on insect sex attractants and 
chemosterilants and the sterilization of insects by irradiation, there is 
an increasing need for the rapid sexing of large numbers of insects. 
Comparative drawings indicating sexual differences found on the ter- 
minal abdominal segments of the pupae of eight important lepidopterous 
pests of field crops are shown in figures 1 to 8. In each species the 8th 
1/ In cooperation with the Texas Agricultural Experiment Station. 
