Prey was impaled on the tip of a needle attached to a phonograph cartridge (PC) connected to a micromanipulator (M2). ![]() A metal pin fitted into one end contacted a piezo-electric device (PE, Vernitron 60690). 1C), supported by a thread from above at one end, and by a thin strip of spring steel (SS) from below at the other, permitting only a slight horizontal displacement as a result of movements of the mantis. The mantis was placed on a balsa wood perch (BP, Fig. Vibrations generated by recoil of the perch at the beginning of the lunge, and by contact of the foreleg femora with the prey, were used to trigger flash exposures of the mantis during prey capture. For the above measurements of body orientation, counterclockwise angles are positive. Angular orientation of the pterothoracic legs is indicated by angles ω 1 and ω 2 formed by h 1 and h 2 with the horizontal. IB), and the third side is the distance between their tarsi (i). Their lengths form two sides of this triangle ( h 1 h 2, Fig. The position of these legs was approximated by a triangle with vertices lying over their ipsilateral tarsi and the joint between pterothorax and prothorax. Position and orientation of the pterothorax is adjusted by the mesothoracic and metathoracic legs. The difference between these two angles and 180° is the angle between the pterothorax and prothorax ( ρ). Angles of the prothorax ( λ) and pterothorax ( K) were measured between their dorsal edges (for the pterothorax, the edge of the wing which covers it) and the horizontal passing through the joint between them. Since the mantids did not always grasp the perch exactly along its long axis, the line determined by the tips of the ipsilateral tarsi was used as the ‘horizontal’ for making angular measurements (dashed lines). To determine how the position of the prothorax is adjusted before release of the attack, the positions of the mantid body and of the prey within the vertical plane of the perch were measured ( Fig. Ml and M2, micromanipulators for adjustment of PE trigger and prey location BP, balsa perch SS, spring steel support. A timer measured the interval between exposures. Recoil from the lunge and foreleg contact with prey were registered by a piezo-electric device (PE) and a phonograph cartridge (PC), respectively, and their outputs (Tl, T2) triggered two electronic flashes, producing a double exposure. (C) Film stage used for double-flash photographs (example in Fig. During the lunge the coxifer is displaced over a distance ( m) at an angle ( ψ) to the horizontal. Orientation of the pterothorax and prothorax are indicated by their angles with the horizontal ( K, λ) and the angle between them ( ρ). Pterothoracic leg position is measured by sides of a triangle ( t, h 1, h 2) with vertices lying over tips of the tarsi and the joint between pterothorax and prothorax, and the angles formed by h 1 and h 2 with the horizontal ( ω 1, ω 2). ‘Absolute’ prey location is the distance d′ of the prey centre from the tip of the mesothoracic tarsus and its angle μ ′ with the ‘horizontal’ (dashed lines, determined by tips of the pterothoracic tarsi). ![]() (B)Position of the mantis and the prey with respect to the perch used to analyse double-flash photographs. Foreleg position is indicated by relative angles of coxa ( α), trochanter–femur ( β), and tibia ( γ). ‘Relative’ prey location is the distance d of the prey centre (radius= r) from the base of the forelegs (coxifer) and its angle μ with the dorsal prothorax. ![]() (A) Position of the foreleg and the prey relative to the prothorax.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |