750 Journal of Agricultural Research voi.xx.No.io 



pupa 



Little is known of the pupa stage, but without doubt it is of short 

 duration, since pupae are rarely found when cocoons are cut open, 

 either shortly after being spun or up to the time they are a year old and 

 have practically all produced adults. 



The following descriptions are prepared from a female pupa. 



Structural characters. — The pupa is similar to, though some- 

 what larger and less hardened than the unemerged adults. The flagel- 

 lum of the antenna varies from 19 to 20 in the number of joints in the 

 specimens counted. The appendages are folded in or toward the venter 

 with the second pair of wings under the first pair which extend caudad- 

 ventrad. The shed prepupal skin is attached loosely to the apex of 

 the pupa's abdomen. 



Color. — The pupa is entirely yellowish, the eyes, apices of the man- 

 dibles, and antennas being the first parts to darken with the develop- 

 ment of the adult. 



UNEMERGED ADULT 



The approach of the pupa toward the mature adult is accompanied 

 by a darkening, or coloration, and hardening of the body wall, which 

 before issuance becomes almost complete, and by the shedding or removal 

 of the pupal membrane or skin, by a reduction in size, and by an in- 

 crease in activity. 



The following descriptions are prepared from an unemerged female 

 adult. 



Structural characters. — The unemerged adult is similar to the 

 mature adult, and the shed pupal skin is attached loosely to the apex of 

 the abdomen. 



Color. — The head is yellowish brown, with the eyes leaden, the anten- 

 nas brownish, the apices of the mandibles brown, and the labium and 

 maxillae yellowish white. The greater part of the thorax is yellow to 

 yellowish white, but some of the posterior sclerites (mesothorax in part 

 and all of the metathorax) are brownish. The wings are nearly com- 

 pletely developed with their veins brownish, and the legs, excepting 

 small portions, are yellowish white. The abdomen has the tergites (ex- 

 cept intersegmental skin) blackish with a broad, white, longitudinal 

 band along the spiracles; the pleural line white; the sternites white 

 medially, brownish near pleural line; and the reproductive parts mostly 

 yellowish. 



LIFE AND SEASONAL HISTORY 



The length of life of a colony, or the time between the depositing of 

 the first egg and emergence of the last adult, may be approximately 

 either 12 or 14 months — 12 months when the eggs are laid in the late 

 summer or early fall and 14 months when the eggs are laid in the later 

 spring or early summer. The length of life of a single colony has been 

 given the name "colony period." 



