Mantisfly

Mantispa styriaca — the European mantisfly — is one of about 400 species in family Mantispidae and one of the most morphologically extraordinary insects in the world. Mantisflies are LACEWINGS (order Neuroptera, the same order that includes antlions and owl flies) that have independently evolved raptorial forelegs and a triangular mantis-like head despite no evolutionary connection to true praying mantises (which are in order Mantodea, a completely separate insect order). The convergent evolution is so complete that mantisflies are routinely misidentified as small praying mantises by both casual observers and entomologists; the differences are visible only on close anatomical examination (mantisfly antennae are filiform vs. mantis bristle-like, mantisfly wings are veined neuropteran rather than the smooth mantis wing structure, and the mantisfly larva is a campodeiform grub completely unlike a mantis nymph). The species' most extraordinary biology is the larval life cycle. First-instar larvae are mobile triungulin-style grubs with eyes and active locomotion. Each larva actively searches out a female spider — typically Lycosidae wolf spiders or Salticidae jumping spiders — climbs onto her body, and hitchhikes for days or weeks (riding on the spider's body, occasionally feeding on hemolymph through small wounds). The larva waits until the female spider produces her egg sac. As the spider deposits and seals the silk egg sac, the mantisfly larva crawls INTO the still-soft sac, becomes sealed inside with the spider eggs, and consumes the entire clutch of spider eggs over the next 2-4 weeks. The larva pupates inside the consumed egg sac and emerges the following year as an adult mantisfly. The strategy is one of the most spectacular spider-egg-sac parasitoid life cycles in the insect world. Adults are 15-25 mm long, slender, with apple-green or pale brown bodies, raptorial green forelegs, and four translucent neuropteran-veined wings. They are aerial predators of small flying insects.