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Psyche 
[Vol. 91 
a spermatophore that is formed within the bursa during copulation 
and contains sperm and secretions. 
Methods and Materials 
All observations were made at the Arizona State University Farm 
Laboratory from March to July in 1983. Here the butterflies use 
cultivated alfalfa as a nectar source and feral and cultivated 
crucifers as oviposition sites and larval foodplants.All hand-reared 
adults were grown from eggs collected in the laboratory or from 
young larvae collected in the field. In the laboratory larvae were 
reared either on broccoli ( Brassica spp.) leaves or on cuttings of 
Sisymbrium irio L. in plastic shoe boxes under variable and 
uncontrolled conditions of light and humidity. The temperature in 
the laboratory was about 24° C. 
Production of secretions during copulation 
To examine the patterns of production of secretions by males, 
virgin females were released next to free-flying males and permitted 
to copulate with them. If the copulation lasted 60 min or less, both 
members of the pair were freeze-killed after the pair separated. 
Longer copulations were thought to indicate dysfunction or recent 
mating by the male. Males in the mated pairs were assessed with 
respect to wing wear (age), forewing length, and body weight (to the 
nearest 0.1 mg) (for techniques, see Rutowski et al., 1983). Females 
were assessed with respect to forewing length and the volume and 
wet mass of material received from the male during copulation (for 
technique see Rutowski et al. 1983). In some cases males were 
weighed and measured without killing so that they could be held 
overnight (without food and water) and returned to the field the 
following day to observe their performance in second matings. Male 
precopulatory body mass was estimated by adding the mass of the 
secretions imparted to his postcopulatory mass. 
To examine the rate of use of the material received during 
copulation virgin females were mated to free-flying males as above 
and then held in cylindrical screen cages (9 cm diameter, 12 cm 
deep) in the laboratory under flourescent illumination. At various 
times after mating females were freeze killed and dissected to 
examine the material remaining in the bursa copulatrix. Sprigs of S. 
irio for oviposition and sugar water for food were available in these 
cages. 
