Species Of Praying Mantis Research Articles

The influence of abrupt forest edges on praying mantid populations

. 1. The concept of an ‘edge’ habitat that is influenced by the biotic and abiotic characteristics of neighbouring habitats is a broadly applied principle in ecology. 2. Ciulfina klassi Giglio-Tos (Mantodea: Liturgusidae) inhabit vertical tree trunk surfaces in a restricted patch of coastal Melaleuca woodlands in the world heritage listed Wet Tropics Region of far north Queensland, Australia. Preliminary observations suggested that abrupt forest edges may have a positive effect on population density in the praying mantis C. klassi. 3. During field surveys over a two-year period, mantid densities were found to be higher at forest edges than forest interiors. 4. Greater sapling recruitment at forest edges may contribute to this edge effect by providing dense patches of tree trunk habitats. 5. The population characteristics of C. klassi are also described here in the context of our current understanding of praying mantid life histories. Aspects of the ecology of this tropical praying mantis species contrast with what is already understood about previously studied temperate species.

Curvature facilitates prey fixation in predatory insect claws

Insects show a large variety in prey capture strategies, with a correspondingly large diversity in predatory adaptations. We studied a specific type of predatory claws, these can for example be found in praying mantis species. The claw is closeable over its entire length and the prey is fixed between the femur (upper arm) and the tibia (lower arm) of the insect leg. The morphology of these predatory claws is diverse. Some species have straight claws covered with spines, while other species have smooth, curved claws. We have studied the mechanics of this femur-tibia type of predatory insect claws, by making a physical model, eventually trying to explain why in some insect species the claws are curved instead of straight. The main results are (1) when comparing curved claws to straight claws, curvature leads to a strong reduction of forces driving the prey away from the pivoting point, thereby reducing the need for friction generating structures. (2) In the curved claw model a position exists where the resulting force on the prey is exactly zero. This is because the normal forces on the femur and tibia are opposed, and in line. At this position the prey is perfectly clamped and not driven out of the claw. This feature does not exist in straight claws. (3) In the curved claw, the prey cannot be placed at a position further than a certain maximum distance from the pivoting point. Near this maximum position, the resulting force on the prey reaches high values because moment arms are near zero. (4) Between the zero position and the maximum position the resulting force is directed toward the pivoting point, which stabilizes prey fixation.