Predatory hunting of cockroach nymphs in a starved praying mantis before and after insulin injection.
The video shows two clips representative of the behavioral changes in the starved baseline condition as well as 15 minutes after insulin injection in the same starved praying mantis. In the first clip, designated in the bottom left corner with a gray box, shows the starved praying mantis perform a head turn towards a distant nymph (~13 cm away, 0:03). The mantis pursues the prey item, closing the distance before striking unsuccessfully at the cockroach. Multiple prey items are then within striking distance of the animal, where she uses her wide field vision to locate and strike at two subsequent nymphs. This behavior requires a large detection range (distance and angle) as well as locomotor coordination to be achieved. In the second clip, the same mantis is shown 15 minutes after 0.05 ml of 200 μg/ml insulin injection. The praying mantis first attends to a cockroach nymph who crosses her field of view (~6 cm away, 0:35) but does not approach nor strike at the prey. At time 1:41, the praying mantis will attend to the largest nymph present in the arena who gets close enough where the praying mantis will opportunistically strike at the item without taking any steps in approach.