Termin: 20.11.2009 Uhrzeit: 12:00 ( c.t. ) - 13:00 ( c.t. ) ( Freitag )
Slippery plants and skillful climbers: ecology and biomechanics of insect surface attachment
Kolloquium
| Referent/in: | Dr. Walter Federle, Dep. Zoology, University of Cambridge |
|---|---|
| Inhalt: | Mechanical factors play an important role in many insect-plant interactions. Some plants have evolved slippery surfaces with wax crystals or lubricating films to keep away or trap insects. Ant-plant interactions in the genera Macaranga and Nepenthes provide two fascinating examples where insects have evolved special adaptations to cope with slippery plant surfaces. To climb on plant surfaces, insect feet not only have to cling strongly to substrates of different roughness, but they also have to be able to attach and detach rapidly, cope with unexpected perturbations and resist contamination. Climbing insects control attachment and detachment not only by active movements but also by purely mechanical 'preflex'-like responses of the musculoskeletal system to external forces. A key mechanism for the control of attachment and detachment during locomotion is the directional dependence of adhesive devices, which make contact when pulled towards the body but detach when pushed away from it. Nevertheless, climbing insects can use their feet for pushing, even on smooth substrates. They achieve this by walking on the proximal tarsus, which is morphologically specialised for pushing. Insect adhesion is mediated by small volumes of fluid secreted into the pad contact zone. The pad secretion is an emulsion, consisting of watery droplets in an oily fluid. Experiments with polymeric substrates suggest that the function of the two-phasic fluid is to prevent the insects from slipping by non-Newtonian properties. |
| Öffentliche Veranstaltung: | Ja |
| Adresse: | Nussallee 4 |
| Weitere Informationen: | http:// |
| Veranstalter: | Die Botanischen Institute und das Graduiertenkolleg 1572 |
