1977] 
Jackson — Dictyna and Mallos 
269 
Table 1. Number of instances of dictynids feeding on different types of prey 
listed according to their estimated relative sizes (prey size/ spider size). When more 
than one individual fed on the same prey item (M. trivittatus), relative prey size 
based on largest spider. 
Species 
Type of Prey 
Smaller 
than 
Spider 
Number of Prey 
Same Larger 
size as than 
Spider Spider 
Total 
Dictyna calcarata 
Diptera 
0 
1 
2 
3 
Dictyna completa 
Diptera 
0 
2 
1 
3 
Dictyna phylax 
Diptera 
2 
0 
0 
2 
Dictyna tridentata 
Diptera 
1 
1 
0 
2 
Mallos dugesi 
Diptera 
0 
1 
0 
1 
Mallos niveus 
Diptera 
2 
0 
0 
2 
Mallos trivittatus 
Diptera 3 
25 
12 
15 
52 
Lepidoptera b 
0 
0 
4 
4 
Conspecific Spider 
0 
2 
0 
2 
a Tipulidae: 14 
Other Diptera: 38 
b Moths 
My approach to the web may have disturbed the spider, causing it 
to depart from the prey. A living tipulid caught in a M. trivittatus 
web will be discussed later. All other carcasses in Table 2 were dry, 
hollow, and almost entirely intact, which is the usual condition of 
prey of these spiders after feeding has occurred. Spiders inject en- 
zymes into their prey, and digestion takes place primarily outside 
the spider’s body. The spiders ingest the prey’s tissues in fluid form. 
Unlike some other spiders, no noticeable mastication of the prey 
occurs with dictynids. Since other species of spiders (salticids, tetrag- 
nathids, etc.) frequently were found inside or near webs containing 
dictynids, possibly some of the arthropod carcasses in Table 2 were 
prey of these species, but most were probably prey of the dictynids. 
Predation on conspecifics (cannibalism) is discussed elsewhere 
(Jackson, 1979b). 
Circadian Pattern of Feeding and Other Activities 
Many more data are available concerning M. trivittatus than for 
the other species. Most of the observations of feeding (88%) for 
