PREDATORY AND SEXUAL BEHAVIOR OF 
THE SPIDER 
SICARIUS (ARANEAE: SICARIIDAE)* 
By Herbert W. Levi 
Museum of Comparative Zoology, Harvard University 
For a period of over 20 years, from 1911 to 1933 (Bonnet, 1945), 
Gerhardt published observations on the sexual behavior of spiders, 
describing sperm induction, charging the pedipalps with sperm, as 
well as mating. The observations (Gerhardt, 1924, 1927, 1930, 
1933) concerned representatives of all available families with the 
hope of obtaining comparative data. Different groups of spiders have 
different methods of sperm induction and different mating positions. 
Gerhardt was more interested in the mechanical aspects of mating 
than in courtship behavior. A helpful summary (in English) of the 
observations of Gerhardt, Bristowe and others is provided by Kaston 
( 1948) . Only in the last few years have there been some experimental 
studies, including observations on the copulatory behavior of spiders 
after removal of their palpi (Rovner, 1966, 1967). Surprisingly, 
courtship continued normally although both pedipalps had been am- 
putated in the penultimate instar and neither sperm induction nor 
copulation was possible. 
During sperm induction, the spider makes a web with silk from the 
posterior spinnerets. A small area, in the web, a substrate, is prepared 
with silk from spinning glands in the epigastric area (Melchers, 1963 ; 
Marples, 1967). On this substrate a drop of sperm is deposited. The 
sperm is drawn into a duct within the pedipalp of the spider, perhaps 
by resorption of a fluid previously secreted by the surrounding glands 
(Cooke, 1966). In some haplogyne spiders (which lack an epigynum, 
a plate with copulatory pores separate from gonopores), both pedi- 
palps are inserted into the drop simultaneously; in Orthognatha (the 
“tarantulas” of American parlance) and most other spiders, alter- 
nately. Some spiders attach the drop below the web and stand above 
while charging the pedipalps; others deposit the drop on the upper 
surface and reach around the edge to charge the pedipalps through 
the web. The pedipalps are recharged after mating. 
*1 would like to thank Dr. J. A. L. Cooke, Oxford University, and Mr. 
W. Eberhard for suggestions, L. R. Levi and Mrs. R. Matthews for editing. 
The observations were supported in part by Public Health Service Research 
Grant AI-01944 from the National Institute of Allergy and Infectious Dis- 
eases. 
Manuscript received by the editor December 15, 1967 
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