Word: exoskeleton
(lookup in dictionary)
(lookup stats)
Dates: during 1970-1979
Sort By: most recent first
(reverse)
...Callahan and Mankin in their lab generated electric fields comparable to those produced during storms. They then confined within the fields several species of insects, including predatory stinkbugs and spruce budworms. The results were invariably the same: the bugs, consisting, as the scientists note, of an excellent dielectric (the exoskeleton) surrounding an electrolyte (the body fluids), displayed brilliantly colored flares from such external points as their antennae, leg joints and jaws. Write Callahan and Mankin: "There is absolutely no doubt that, given the right weather conditions, nature can produce a high enough electric field to light up flying insects...
...chemical analysis. They soon determined that it was hidden in a region filed the pleural arch near the base of the flea's hind legs. In flying insects, the pleural arch is the site of the wing-hinge ligaments, the place where the wings are attached to the exoskeleton, hard outer covering. In fleas, as well as in dragonflies, locusts and certain other insects, the arch serves another purpose: as a repository for an extraordinary elastic-like clump of protein called resilin that can be stretched, and contracted back to its original shape, faster than any known rubber...
...flea prepares to jump, it crouches like a runner in the starting block, lowering it's head and contracting its body. Thes actions compress the resilin and engage hooklike "catches" in the flea's exoskeleton that prevent the resilin from expanding prematurely. In effect, the flea has "cocked" itself for the leap. Then, at the right moment, it releases the catches. The resilin snaps back to its original size, like an uncoiling spring, and exerts a sharp downward force on tendons connected to the upper part of the hind legs. That launches the flea into...