1974] 
Waldorf — Sinella coeca 
255 
Table 1. Characteristics of male and female bouts of cleaning behavior. 
Number of 
bouts/animal 
Length of 
bouts (in sec) 
X 
n 
SD 
X 
n 
SD 
Males 
1.88 
50 
1.33 
29.4 
94 
38.6 
Females 
1.38 
50 
1.23 
23.8 
69 
29.5 
Results 
The data in Table i present the overall characteristics of males 
and females. Comparison of the lengths of bouts using a t-test shows 
that these are not significantly different (t = 1.049). However the 
number of bouts is significantly larger in males than in females 
(t = 1.949; .05>P>.0i). Rather than the expected differences, 
it appears that male sessions of cleaning are of equal length and 
more frequent than those of females. 
At times of observations some individuals were pharate, some vials 
contained exuviae and others eggs. These allowed the animals to be 
subdivided into groups corresponding approximately to position in 
instar. Among the males only two ecdysed within the 24 hour isola- 
tion period, a sample too small to be meaningful. However among 
the females, the categories were sufficiently large to permit evaluation. 
Table 2 gives the data for females of different types. Of the 
four pharate females, none exhibited any cleaning behavior. Com- 
parison of recently ecdysed females and females with eggs to remain- 
ing females revealed no significant differences in bout length. In 
contrast, comparisons of cleaning frequency among these females 
showed that females with eggs clean significantly more often 
(t = 2.488; 25df; P .01) than other females. 
Discussion 
As Simon (1961) has noted, the antennae, the location of im- 
portant sensory receptors, are cleaned most often. There is possibly 
a positive correlation between frequency of cleaning and the required 
sensitivity of receptors. In pharate females the old receptors have 
presumably lost their nervous connections, so that there is no adaptive 
advantage in cleaning them. In contrast, females that have recently 
deposited eggs are sensitive to the required stalked spermatophores 
on the substrate. If this species has alternate reproductive and non- 
