2. Behavioral Biology TALKS - Deutsche Zoologische Gesellschaft

�11 Taina Conrad A 704 / 15:00
The role of vibrational communication in mason bees
Authors: Taina Conrad 1 , Robert J. Paxton 1 , Manfred Ayasse 1
Affiliation: 1 Experimentelle Ökologie, Universität Ulm
Vibrational signals are used by various species when communicating, and commonly
play an important role in mating. Even though many bee species are known to emit
vibrational signals during mating, there are almost no studies on the function of
these vibrations. Vibrational signals are produced by bees through vibrations of the
thorax, as in the precopulatory mating behavior of Osmia rufa. We hypothesized that
a female might use these thorax vibrations to choose a suitable mate and, if these
signals are species-specific, they can also be used as species isolation barriers. In
order to investigate the function of these thorax vibrations, we measured and
compared the accepted and rejected male vibrations during precopulation using a
laser vibrometer. For the role as a pre-mating isolation barrier we investigated
vibrations of O. rufa from England, Germany and Denmark and of the sister species
O. cornuta.
Our results clearly showed that male vibration burst length was significantly longer in
accepted than in rejected males (Conrad, Paxton et al. 2010). Vibrations may
therefore indicate vigor and assure that the males selected by females are in fact the
healthier ones. Furthermore we found significant differences in the frequency and
modulation of vibrational signals between O. rufa and O. cornuta and between the
subspecies of O. rufa, supporting our hypothesis that they might have an additional
function as a pre-mating isolation barrier. Based on these results we conducted
bioassays to further investigate how vibrational signals are used by the bees. For
these we used an interesting new technique involving magnets and an inductor to
experimentally change the bees vibrations.
We would like to thank the DBU for funding this project.
Conrad, T., R. J. Paxton, et al. (2010). Female choice in the red mason bee, Osmia rufa (L.)
(Megachilidae)." Journal of Experimental Biology."
�12 Hellena Binz A 704 / 15:15
Antipredator behavior in the wood cricket Nemobius sylvestris varies among
distinct spider species and their biological traits
Authors: Hellena Binz 1 , Roman Bucher 1 , Florian Menzel 1 , Martin H. Entling 1
Affiliation: 1 Johannes Gutenberg University Mainz
Predators affect their prey not only via consumption, but also through nonconsumptive
effects. These effects, e.g. changes in prey behavior, often exceed
effects through consumption. Spiders are dominant predators in almost all terrestrial
ecosystems and prey on a wide range of arthropods. Therefore spiders can elicit
strong antipredator behavior in insects and influence ecosystem functioning.
We investigated the occurrence and strength of antipredator behavior (APB) of the
wood cricket Nemobius sylvestris towards 14 widespread and common hunting
spider species by performing two different behavioral arena experiments. Mobility of
crickets was recorded (1) either in presence or absence of spider cues in separate
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