Transcript Poster from 2012

Mating Behavior of Cyphoderris Strepitans
Introduction: Cyphoderris Strepitans (sagebrush crickets) are unique in their
mating behaviors. The male calls by brushing his tegmina (anterior wings)
against each other which creates a sound in the same fashion as plucking a
comb with a toothpick. The call alerts females of a male’s presence and may
also indicate his sexual status (virgin vs. non-virgin) to females. The male’s
fleshy, white, hind wings provide a nuptial food gift to the female as she mounts
during mating. While the female is preoccupied with feeding on these hind
wings, the male attaches a spermatophore to the female. Post-copulation, the
male’s tattered hind wings darken and allow researchers to determine his sexual
status: virgin vs. non-virgin.
Purposes:
Virgin male – intact hind wings
Non-virgin male – damaged wings
(1) Determine if diet influences male willingness to call.
(2) Determine if diet influences female mount-time.
1. Diet vs. # of Periods with Mating Calls
2. Mount time vs. Diet in Females
Male sagebrush crickets were divided into two diet groups, with half being on a high
and the other half on low diet for two days. High diet crickets were given five pollen grains, a
slice of apple (water source), and a piece of cat chow every day. The low diet consisted of 2
grains of pollen and a slide of apple every day. The males were paired with females overnight in
a clear plastic box and their behaviors were video recorded. Male calling behaviors were scored
by dividing the night up into five-minute periods of time. During video analysis, periods were
marked based on whether or not a male called. Total marked periods were determined for each
male. As an extension, we decided to examine cricket mass data to determine if the two diets
affected mass. Pre and post-diet masses were used to determine the percent change in mass for
each individual.
Female crickets were divided into two
diets: low and high (same as the males). The
females were then placed in a clear plastic box
with a male cricket, as described in the previous
section. Through video analysis, total mount time
exhibited by each female was recorded.
Average Change in Mass vs. Diet
# Periods Calling vs. Diet
80
3.00%
70
2.00%
Mount Time vs. Diet
3000
1.00%
50
0.00%
40
High
Low
30
20
2000
Low
-1.00%
-2.00%
High
Time (sec)
60
Percent Change
# Periods Calling
2500
1500
High
Low
1000
-3.00%
10
-4.00%
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Subject #
-5.00%
500
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14
Subject #
-6.00%
Conclusion
The overall goal of our experiment was to to determine whether diet
played a significant role in the mating behaviors of Cyphoderris Strepitans. The
first part of this experiment was to determine how diet of a male cricket
affected the number of mating calls it performed. The data suggest that diet
does not have a significant effect on the number of mating calls performed by
males (p=0.937). This conclusion led us to question whether the diets had a
significant impact on cricket mass. We compared the pre and post-masses of
males on a high diet with the mass of those on a low diet. We found that diet
did indeed have have a significant impact on the masses of crickets (p=0.036) In
summary, although variation in diet created significant mass differences, it was
not shown to create significant differences in calling behavior.
Our final experiment concerned the effects of diet on female
willingness to mate. We found that there was not a significant correlation
between mount time and female diet (p=0.56), but this conclusion is not
definitive because sample size was limited; further testing may be warranted.
Right: A mounted female feeds
on the hind wings of a male
while he attempts to attach a
spermatophore.
Left: Cyphoderris Strepitans