VARIATIONS IN CLEANING BETWEEN THE SEXES OF 
SINELLA COECA (COLLEMBOLA: ENTOMOBRYIDAE)* 
By Elizabeth S. Waldorf 
Department of Zoology 
Louisiana State University 
Baton Rouge, Louisiana 70803 
With the widespread and frequent occurrence of pheromones 
among insects, it is easy to appreciate the significance of cleaning 
and grooming behaviors. However these behaviors are as yet poorly 
known. Among springtails two papers by Simon (1961, 1963) present 
the most thorough reports. These describe the types of cleaning in 
representatives of several families, noting the widespread, though 
infrequent, use of cleaning droplets released from the mouth. 
My work examines Sinella coeca (Schott) (Family Entomobryidae) 
for behavioral differences between the sexes. In particular, I have 
determined the frequency of cleaning and the duration of bouts of 
cleaning behavior. The initial expectation is that the sexes will spend 
about equal time cleaning. However, since males are more active, 
moving about most of the time, their bouts of cleaning are probably 
shorter. To compensate, I expected males to have more frequent 
cleaning sessions. An experiment was carried out to test these 
expectations. 
Methods 
Sinella coeca was reared in mass culture as described previously 
for Sinella curviseta (Waldorf, 1971). Cultures were maintained 
at room temperature (23 0 ± i°C) and supplied commercial yeast 
as food. Males and females were isolated in individual glass vials 
with plastic caps. The vials, measuring 18.1 mm in inner diameter, 
contained a moist plaster of paris-charcoal substrate (to maintain 
high humidity) and food. After 24-26 hours of isolation, each animal 
was observed for five minutes, and the number of bouts of cleaning 
and the total time (out of 5 minutes) engaged in cleaning recorded. 
This procedure was followed for 50 males and 50 females. To 
prevent bias the vials were mixed so that during the observation 
periods the sex of test animals was usually unknown. 
* Manuscript received by the editor May 20, 1974. 
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