1977] 
Jackson — Dictyna and Mallos 
273 
With the exception of the evening observations in the culvert, 
the amount of time spent observing webs was recorded only ap- 
proximately. These estimates were used for the calculations in 
Table 3. Based on these data, it seems that feeding and general 
activity of the dictynids in this study occur predominantly in the 
evening. 
Initial Contact of Spider with Prey 
Certain spiders, such as some araneids and theridiids, wrap their 
prey either before and/or after biting; however, this does not occur 
in the Dictynidae. These spiders seem to simply rush out and bite 
the prey. If the prey is violently struggling, the spider may walk 
or stand in the vicinity until activity subsides. 
Bristowe (1958) reported that dictynids invariably grasp their 
prey initially by a leg. The initiation of feeding was seen for one 
M. niveus and five M. trivittatus. In each case, the spider initially 
grasped a leg or antenna of the prey. Of the spiders already feeding 
when found, some were feeding on the head, thorax, or abdomen 
of the prey (Fig. 1), although data were not recorded. M. gregalis, 
M. trivittatus, M. niveus, and D. calcarata were maintained and 
fed in the laboratory, and it was noted that the spiders sometimes 
initially grasped the prey by its head or body rather than by an 
appendage. For M. gregalis in the laboratory, the location at 
which the spider first grasped the prey was recorded for 66 indi- 
viduals: leg, 44%; head, 15%; abdomen, 14%; thorax, 11%; wing, 
9%; antenna, 7%. All of these flies were active when contacted. 
Once I saw an opilionid walk onto a web unit containing an 
adult female M. trivittatus. The spider rushed out of its nest and 
grasped a leg of the opilionid with its chelicerae. Immediately, the 
spider released the opilionid and returned to its nest, suggestive of 
opilionids being distasteful to dictynids (see Bristowe, 1941). Sev- 
eral minutes later, the opilionid escaped from the web. 
Extension Lines 
Webs of M. trivittatus frequently contain long, heavy lines of 
silk (extension lines) that extend to objects some distance from the 
mesh (Jackson, 1978). Once in Utah I found an extension line 
fastened at one end to a mesh, with a female M. trivittatus inside 
the nest. On the other end, a tipulid fly was tethered by its thorax. 
