26 
Psyche 
[ March 
the other in Psychid rearings. In parthenogenetic species, 
females are either the only form known or greatly outnum- 
ber the males. In America, Dr. Jones has mentioned (Tr. 
Am. Ent. Soc., LIII, 310, 1927) a collection of thirty-odd 
cases of Eurukuttarus edwardsi Heyl. of which only one 
was female; the same author (Ent. News, XXXIII, 130. 
1922) bred some forty males without a single female from a 
collection of Psyche celibata Jones. Returning to Fumea 
casta , a similar numerical ration between the sexes was 
found in many of the Massachusetts collections, as shown 
in the following table based on adults bred from cases col- 
lected at time of pupation; where cases failed to yield 
adults, they were opened and the sex determined from the 
enclosed pupae; in those few cases where the larvae died, 
accurate sex determination was not considered possible, and 
such individuals are ignored in the tabulation : 
Table 1. — Sex ratio in certain collections of Fumea 
casta in Massachusetts. 
Date of 
collection 
Place of collection 
Number of 
individuals 
% £ S 
% $ $ 
May 6, ’33 
Arnold Arboretum ..... 
7 
100 
000 
May 6, ’33 
Stoney Brook 
70 
100 
000 
May 12, ’33 
Stoney Brook 
69 
100 
000 
May 13, ’33 
Arnold Arboretum 
100 
100 
000 
May 22, ’33 
Arnold Arboretum 
130 
100 
000 
May 22, ’33 
Fenway 
25 
100 
000 
May 22, ’33 
Jamaica Pond 
100 
93 
7 
June 5, ’33 
Jamaica Pond 
375 
34 
66 
Interpretation of the above table is complicated by the 
fact that the Jamaica Pond colony was some two weeks be- 
hind the other colonies in reaching maturity ; in fact, for a 
time the larvae of this colony were considered as possibly of 
another species because of their smaller size. Therefore, 
the high percentage of females in the latest collection does 
not necessarily mean that similar results would have ob- 
tained if later collections had been made at the other sites. 
It appears from the table that the earliest larvse to pupate 
are the males, which conforms with the condition in many 
other Lepidoptera. The striking preponderance of males 
