216 
Psyche 
[Vol. 87 
species died (Table 1). When maintained with insect prey, survival 
rates for all sex/age classes of M. trivittatus and D. calcurata were 
high. (No females of either species died during the 30-day period. 
Only 3 immatures of M. trivittatus and one of D. calcurata died. For 
the males, see Table 1.) 
Table 1. Adult males of three different species maintained for 30 days with either 
Musca domestica or Drosophila melanogasler provided as prey. G-tests of indepen¬ 
dence, with Yates Correction, carried out separately for survival rates of those 
provided with each of the two types of prey: P < 0.001. 
Prey 
Species 
Number of Males 
Survived Died Total 
G 
Mallos gregalis 
12 
8 
20 
Musca 
Mallos trivittatus 
20 
0 
20 
15.864 
Dictyna calcurata 
19 
1 
20 
Mallos gregalis 
21 
14 
35 
Drosophila 
Mallos trivittatus 
19 
1 
20 
20.008 
Dictyna calcurata 
20 
0 
20 
Since males of M. gregalis lack functional cribella (Jackson, 
1979a), their webs are not adhesive and evidently not very effective in 
prey capture; no males were observed feeding in their own webs. 
However, males of M. trivattatus and D. calcurata, which also lack 
functional cribella (unpub. obs.), were observed feeding in their own 
webs. Perhaps males of M. gregalis rarely move off the large 
communal webs containing females and immatures. In contrast, 
while searching for mates, males of M. trivittatus and D. calcurata 
may spend considerable time away from webs containing females and 
immatures; and capabilities of capturing prey without the use of, 
adhesive webs may be adaptations related to this. 
Within 30 days, all males died in the colonies kept without insect 
prey, but more than half survived in their own webs when insects were 
available. This suggests that males may have fed at times other than 
when observed, perhaps by scavenging on insects that died in their 
cages. 
