A study published in Current Biology describes the discovery of fossilized lacewing larvae with specialized adaptations that made these infantile insects spider-killing machines. Scientists found several amber-encased predecessors to modern lacewings—long, thin flyers with veiny, gossamer wings—in the forests of northern Myanmar’s Hukawng Valley. The trove dates to the mid-Cretaceous period about 100 million years ago and contained both young and adult lacewings, but it was the juveniles that stood out. The larvae of Pedanoptera arachnophila were maggotlike in general body shape, but with incredibly long, gangly legs “so fine in structure that it would seem to be impossible for the legs to support the more massive body,” the authors write. These legs terminated with serrated claws that, although unique among known lacewing larva, are commonly seen in other insects that glide easily over spiderwebs. Combined with the knowledge that lacewing larvae are known to be active predators, a picture emerges of this tiny, ancient hunter: a larval lacewing with impossibly spindly legs silently grasping along a spider’s silken threads, closing in on its quarry before dealing its fatal blow with sharp pincer jaws. The adult lacewings found in the amber were no predatory slouches, either, with long legs, strong mandibles and an elongated necklike structure, but they were more likely generalized hunters, not spider specialists.

Source: Science Mag