National Geographic : 1991 Sep
In the big leagues of predation, Mopsus mormon plays rough. Stalk ing along plant leaves near water in Australia, it takes on other fierce predators. A female Mopsus strikes a damselfly in the insect's equivalent of the jugular (above), even as the victim attempts a takeoff. Closely matched as top hunters, praying mantises and Mopsus usually treat each other with cautious respect, circling and going their sepa rate ways. But, given a clear chance, they attack. Mopsus hits the weakest spot (right top), but sometimes the mantis prevails (right bottom). Yet set a prey size frog before a Mopsus (right), and the spider makes no attempt to attack. It's as if this little vertebrate is not in the spider's data bank at all, as food or foe.