GROOMING THROUGH THE REPRODUCTIVE 
CYCLE IN MALE SINELLA COECA 
(COLLEMBOLA: ENTOMOBRYIDAE)* 
By Elizabeth Waldorf 
Department of Zoology and Physiology 
Louisiana State University 
Baton Rouge, Louisiana 70893 
Introduction 
Pheromones function in several roles important in insect repro- 
duction : location of associate, species recognition, sex recognition, 
and as aphrodisiacs. The receptors that detect most sex phero- 
mones are located on the antennae and mouth parts. Grooming 
behaviors free these sensory surfaces of foreign materials permiting 
their optimal functioning. 
Collembola are commonly very abundant in leaf litter and soil 
ranging up to 200,000 per m 2 (Hale, 1967). They contribute by 
their food processing and locomotion to soil genesis and the main- 
tenance of soil fertility. Their abundance is due not to a large 
diversity of species, but to a high reproductive potential (Kuhnelt, 
1961). 
Reproduction utilizes indirect sperm transfer via stalked sperm- 
atophores. In Sinella curviseta Brook (Family Entomobryidae) 
spermatophore deposition by males is stimulated by a female sex 
pheromone (Waldorf, 1974a). Under ideal conditions, Sinella 
curviseta females can deposit an average of 45 eggs every 8 days for 
3 months (Waldorf, 1971; Niijima, 1973). Both sexes in this 
species release gametes during specific intervals that alternate with 
nonreproductive periods (Waldorf, 1971). Males and females molt 
twice between successive reproductive intervals. 
Although reproduction has not been described in Sinella coeca 
(Schott), preliminary work suggested that the frequency of cleaning 
might vary with the reproductive condition of the individual (Wal- 
dorf, 1974b). These data demonstrate a difference between the 
sexes in the frequency of grooming, with males grooming more 
often. In addition, the frequency of grooming in females depends 
on the reproductive condition of the female. 
This study examined the frequency of grooming in Sinella coeca 
males in a sequence of reproductive conditions. Since females with 
* Manuscript received by the editor January 16, 1976 
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