20th International Congress of Arachnology

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Student - oral presentation
Behavioral responses to varying acoustic
stimuli in the wolf spider Gladicosa gulosa
*Alexander L. Sweger, George W. Uetz
Department of Biological Sciences University of Cin-
cinnati P.O. Box 210006 Cincinnati, OH 45221, USA
Vibration is an important part of the sensory world
of spiders, and many species use vibratory signals as a
major part of their conspecific communication. While
nearly all male wolf spiders produce vibrations during
courtship, the “purring” wolf spider, Gladicosa gulosa
(Walckenaer 1837), also produces an airborne acoustic
signal in conjunction with its vibratory display. However,
with limited previous research on this species, the
behavioral and evolutionary significance of this com-
ponent remains unknown. Given that spiders are not
known to possess sensory structures for direct perception
of airborne sound, this raises a key question - do males
or females of this species respond to conspecific acoustic
cues? We measured responses of male and female G.
gulosa to isolated acoustic signals under various condi-
tions. Individuals were placed in an anechoic chamber
on either a vibrating (paper) or non-vibrating (granite)
substrate. In one experiment, spiders were presented
with one of three stimuli- no stimulus, a neutral acous-
tic stimulus (white noise), or the airborne component
of a male conspecific signal. In a second experiment,
spiders were presented with a conspecific male signal at
one of three set amplitudes- the population mean, popu-
lation maximum, and beyond population maximum.
We then measured individual movement patterns and
relevant behaviors. We found significant differences in
phonotaxis, movement patterns, and association with
the stimulus based on the type of stimulus presented.
Responses also varied by sex and the vibration conduc-
tion capacity of the substrate. These results suggest that
while acoustic stimuli are likely perceived as substrate
vibrations, acoustic signaling may have a role in the
communication network of this species.
Keywords: wolf spider, behavior, communication, vibra-
tion, sound
Student - poster presentation
Behaviors associated with mating success
in the wolf spider Gladicosa gulosa
Alexander L. Sweger, Corey J. Vaughn, George W. Uetz
Department of Biological Sciences University of Cin-
cinnati P.O. Box 210006 Cincinnati, OH 45221, USA
Behaviors associated with courtship and mating- both for
courting males and choosy females- can be diverse. Conse-
quently, investigating ecological variables associated with
courtship and mating behaviors requires a baseline under-
standing of the behaviors themselves, and which behaviors
are most closely associated with successful mating. Estab-
lishing a significant association between certain behaviors
and mating success can elucidate which features may be
indicative of male quality and which behaviors females
might use to communicate acquiescence. Future studies
can then use behavioral responses in controlled condi-
tions as metrics for male quality and female choice. The
“purring” wolf spider, Gladicosa gulosa (Walckenaer
1837) raises interesting evolutionary questions due to an
airborne acoustic signal that males produce in conjunction
with their vibratory display. However, with limited previous
research on this species, there has been no quantitative
evaluation of which behaviors in either sex are indicative
of a higher probability of successful mating. We paired
male and female G. gulosa under controlled laboratory
conditions and recorded all visual and vibratory signals
from both sexes. We then provided operational definitions
of all observed male and female behaviors and quantified
said behaviors in association with mating success and
cannibalism events. We found behaviors in both male
and female behaviors that indicated a high probability of
mating success, as well as latency effects for male court-
ship. Females showed at least four visual behaviors that
indicated receptivity (i.e., were followed by acquiescence to
mate), several of which showed a significant positive corre-
lation with male vibratory amplitude. These results provide
a metric for future manipulations of ecological vari-
ables in association with sexual selection in this species.
Keywords: wolf spider, behavior, communication, court-
ship, sexual selection
188 DENVER MUSEUM OF NATURE & SCIENCE REPORTS | No. 3, July 2, 2016
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