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[June 
Table 2. Characteristics of cleaning bouts by females of various types. 
X 
Number of 
bouts/animal 
n 
SD 
X 
Length of 
bouts (in sec) 
n 
SD 
Pharate females 
0 
4 
0 
— 
— 
— 
Recently ecdysed 
females 
1.63 
19 
1.34 
22.4 
31 
29.0 
Females with eggs 
2.1 
9 
1.05 
20.8 
19 
28.9 
Other females 
1.05 
18 
1.00 
29.1 
19 
31.7 
reproductive instars with oviposition confined to early in the repro- 
ductive instar as Sinella curviseta (Waldorf, 1971), newly ecdysed 
females are possibly a mixture of two types: sensitive ones early in 
the reproductive interval and indifferent, or less sensitive ones, early 
in the nonreproductive instar. Although the distribution of numbers 
of cleaning bouts per female is not bimodal, the mean of this category 
is 1.63, approximately the average (1.57) of the sensitive group 
with eggs and the remaining females. Note also that the variance 
of the number of bouts of recently ecdysed females is 1.796 and 
that of females with eggs and remaining females are 1.102 and .998 
respectively. 
Considering males, Mayer (1957) has reported that males of 
Sminthurides aquaticus Bourlet clean more frequently when clasping 
the antennae of females than when alone. This is consistent with 
the hypothesis that these males are highly sensitive to olfactory 
stimuli. 
The data indicate that males engage in more total cleaning than 
females. My recent studies of Sinella curviseta (Waldorf, in manu- 
script) demonstrate that females of this species produce a sex 
pheromone. This stimulates spermatophore deposition by males in 
the reproductive instar. Of the males in the present study 48 of 50 
were in the reproductive instar at observation time. By frequent 
cleaning, these maintain their sensitivity to olfactory stimuli including 
possible pheromones. 
Literature Cited 
Mayer, H. 
1957. Zur Biologie und Ethologie einheimischer Collembolen. Zool. 
Jahrb. abt. Syst. Okol. Geogr. Tiere 85: 501-570. 
