1977] 
Tietjen — Dragline- Following by Spiders 
173 
laboratory up to 4 days old will elicit following-behavior in male 
L. rabida and male L. punctulata; and a cage substratum with 
female silk elicits courtship behavior for over a month (Tietjen, 
unpub. data), indicating that the spider pheromone does not decay 
over a relatively long period of time. 
Female lycosid spiders exhibit low motility during the breeding 
season and adopt a “sit and wait” reproductive strategy; the highly 
active males seek out the females (Hallander, 1967a, 1967b; Hol- 
lander, 1972; Muma, 1973; Richter, et ah, 1971). Mathematical 
modeling of females laying no silk trails and silk trails of various 
lengths indicates that the presence of silk effectively increases the 
size of the female target as perceived by the searching male (Tietjen, 
unpub. data). Thus, the ability of male L. rabida and L . punctu- 
lata to follow conspecific female draglines to the source increases 
the reproductive success of these males over spiders that depend on 
chance encounters in a heterogeneous environment. Female silk 
also alerts the male to the presence of a female conspecific and, as 
shown in L. punctulata, decreases the courtship latency. The latter 
two functions effectively reduce the likelihood of intraspecific can- 
nibalism (Platnick, 1971). 
Contact sex pheromones associated with the female dragline are 
known to induce courtship in conspecific male spiders (Dijkstra, 
1970; Dondale and Hegdekar, 1973; Hegdekar and Dondale, 1969). 
Results from the present study support the hypothesis that a phe- 
romone associated with the female dragline elicits courtship in re- 
ceptive males, i.e., these behaviors are not dependent exclusively 
upon tactile information provided by the silk. Both L. rabida and 
L. punctulata are found with a variety of other spider species. 
Dependence on a pheromone to elicit sexual behavior in males 
would reduce the chances of males following draglines of other 
species and thereby adversely affecting the time budget allocated 
for reproductive purposes. 
The propensity of male L. rabida not to follow ground lines 
which cannot be plucked by the palps (thereby providing little tac- 
tile input) and their occasional following of imitation draglines, 
which provide no chemical cues, indicate that the pheromone is 
responsible only for initiating the following behavior in males. 
Once a male is following a dragline, tactile cues appear to be ade- 
quate. Males are expected, however, to occasionally sample the 
trail for female pheromone, as only 38% of male and imitation 
