76 
Psyche 
[March 
Table 4. Distribution of sex/ age classes of M. trivittatus within web complexes. 
Based on occupied web units. No. of spiders: means ± S.D. Females, Immatures, 
Males: percentages of the total found for each that were in each part of the web 
complex. Total: Number of spiders — mean ± S.D. for spiders — per web unit 
(spiders in interstitial web included with nearest web unit); Females, Immatures, 
Males — percentage of total number of spiders belonging to each sex/ age class. 
Number of 
Spiders 
Females 
Males 
Immatures 
Inside Nest 
1.5 ± 1.88 
93.33 
50.00 
52.49 
Inside Mesh 
Less than 2 cm from Nest 
0.1 ± 0.47 
6.67 
30.00 
4.32 
More than 7 cm from Nest 
0.1 ± 0.38 
0.00 
20.00 
5.98 
Inside Interstitial Web 
0.9 ± 2.19 
0.00 
0.00 
37.21 
Total 
3.1 ± 4.83 
12.64 
2.81 
84.55 
see Buskirk (1975) and Lubin (1974). With the dictynids, we need to 
compare the varied species with respect to the importance of each 
potential advantage and disadvantage, given the nature of the 
resources each species exploits. 
PHENOLOGY 
Most Dictyna and Mallos probably have an annual life cycle in 
nature, with adult females and males present during spring, summer 
and/or fall (Chamberlin and Gertsch, 1958). The mating season for 
Mallos species generally seems to be later than that of Dictyna 
species, although the season for some species may last many 
months. Since both adult males and adult females were found, 
evidently each census was carried out during the mating season of 
the species involved, although not necessarily during the peak of the 
season for all species. No doubt, if censuses had been undertaken at 
different times of the year, different ratios of each sex/ age class 
would have been found for each species. 
Seasonal changes in the ratios of the different sex/ age classes in 
laboratory populations of M. gregalis apparently occur, although 
data have not been collected. Each sex/age class was found 
throughout the year, but males were less numerous in winter than in 
other seasons. The differences in adult sex ratios in the two types of 
censuses of M. gregalis may be a reflection of the tendency, noted 
during casual observation, for females to predominate in the 
interior of webs, with males predominating on the exterior. How- 
