14 
Psyche 
[March 
(1976) concluded that colonial species of Anelosimus were more 
harmful than beneficial in Venezuelan orchards, where they are 
actively treated with pesticides. 
Most web spinning and repair occurred at night. Webbing was 
spun as several spiders reinforced draglines from which they 
dispersed to spin subsequent peripheral silk or dense platform silk. 
This behavior was qualitatively the same as that found in A. eximius 
(Brach, 1975). Unlike A. eximius (Brach, 1975), A. lorenzo did not 
always found colonies at the extremities of leaves or branches. 3 of 
the 5 large colonies, and 7 of the 12 smaller colonies were located at 
positions intermediate between the twig or branch junction and its 
tip. This behavior is much like other species of Anelosimus (Stejskal, 
1976). 
Small colonies were always found in trees adjacent to large 
colonies, hinting that colony foundation is carried out by small 
groups of spiders, or sociotomy (Jackson and Joseph, 1973). All the 
small colonies observed appeared before the onset of cooler winter 
weather. The large size of colonies, both in populations and webbing, 
and conversations with local farmers, suggest that colonies are 
perennial. Stejskal (1976) observed repeated colony relocation over a 
3 yr period, and attributed this activity to the dry microenvironment 
produced when the spiders’ activities killed leaves. 
Social interactions. In a rigorous analysis of social behavior in 
the Theridiidae, Kullmann (1968, 1972) ranked A. eximius {=Theh- 
dion eximius) at the pinacle of social evolution within this family. 
Wilson (1971) considered A. eximius to be quasisocial, due to the 
presence of members of the same generation in communally con¬ 
structed and maintained webs, the existence of communal coopera¬ 
tion in prey capture, and the indiscriminate feeding of the juveniles. 
Brach (1977) emphasized the importance of cooperation between 
adults, or parasociality (Shear, 1970), in the evolution of social 
behavior in Anelosimus. That A. lorenzo parallels A. eximius at 
every level of behavior observed (Table 1), suggests that quasisocial¬ 
ity is probably quite widespread within Anelosimus. A. rupunum, 
with extensive communal webs and populations in excess of 1,000, is 
also probably quasisocial, and as more observations are made on 
other species, this list will undoubtedly have to be increased. It is 
tempting to speculate that some reports on the social behavior of A: 
eximius may have inadvertently been of other species, especially due 
to the high degree of morphological similarity found within species 
groups. 
