Speakers

Prof. William Brown, SUNY Fredonia, USA 3-3:50 p.m. (including discussion)
Diptarup Nandi, CES 4:10-4:35 p.m. (including discussion)
Manvi Sharma, CES 4:35-5 p.m (including discussion)

Talk 1: The behavioral ecology of sexual cannibalism in praying mantids
William D. Brown, Department of Biology, State University of New York at
Fredonia
I will present work that my students and I have doing on sexual
cannibalism in the praying mantid Tenodera sinensis. Sexual cannibalism in
most predatory arthropods occurs when the female kills and consumes the
male before, during, or after copulation. The act obviously has strong
potential for generating sexual conflict but evolutionary models suggest
that degree of conflict over cannibalism will depend on the expected
mating frequency of males and additional offspring produced from the
resources obtain by cannibalism. Thus males are predicted to alter their
risk-taking during approach of females depending on perception of mate
availability and the fecundity benefits of cannibalism. I will present the
results of a series of experiments in which we examine the effect of (1)
level of predatory risk, (2) frequency of mating opportunities for males,
and (3) use of male soma for offspring production by females. I will also
discuss our current work assessing mating opportunities in the field, and
our future plans to measure natural mating frequencies and patterns of
paternity to more accurately assess the costs and benefits of falling prey
to a mate.

Talk 2
A sensory ecological perspective on mate sampling strategies: Models and
an empirical test
Speaker: Diptarup Nandi, CES
Abstract
Mating behaviour in animals often involves communication, wherein signals
are produced by individuals of one sex to attract members of the opposite
sex from a distance. Long-range communication signals thus play a central
role in mate search and mate choice in such systems. Among the different
aspects of mate choice, mate sampling has been less explored despite its
significance. Though analytical models of mate sampling have demonstrated
significant differences in individual fitness returns for different
sampling strategies, these models have rarely incorporated relevant
information on the ecology of signalers and sensory physiology of
receivers, both of which can profoundly influence the optimal performance
of a sampling strategy. In this study, we used simulation models to
compare the costs and benefits of different female mate sampling
strategies in an acoustically communicating field cricket (Plebeiogryllus
guttiventris), by incorporating information on relative spacing of callers
in natural choruses, their signal intensity and the effect of signal
intensity on female phonotaxis behaviour. The optimal strategy that
emerged reflected the physiological mechanisms of sound signal
localization (“passive attraction”) rather than active sampling. When
tested empirically in the field, female behaviour was also consistent with
the optimal strategy predicted.

Talk 3
Title: Oviposition site selection response to larval predation risk in
Aedes aegypti
Speaker: Manvi Sharma
Abstract
Animals ovipositing in discrete aquatic patches avoid patches with high
predation risk on their offspring. In nature, magnitude of larval
predation risk varies across patches yet this risk has mostly been studied
at one level of magnitude. We tested how a females of a mosquito species
Aedes aegypti assess a gradient in larval predation risk across
oviposition sites. To understand underlying trade-offs associated with
patch-selection decisions, we quantified consequences of possible patch
selection decisions by measuring larval survivorship across a predation
risk gradient. We find larval survivorship reduced drastically with
increasing predator density. Surprisingly, adult females did not reject
predator pools altogether, but reduced oviposition in “unfavourable”
pools. We suggest that larval predators may provide a release from intense
larval competition and that the interplay between larval predation and
competition may influence the nature of female-avoidance response to
larval predator densities. We also suggest that females make oviposition
decisions at pool network scale.