of a scorpion, the tip containing an enlarged structure called the genital bulb. The caterpillar-like larvae have hard sclerotised heads with mandibles (jaws), short true legs on the thorax, prolegs on the first eight abdominal segments, and a suction disc or pair of hooks on the terminal tenth segment. The pupae have free appendages rather than being secured within a cocoon (they are exarate). Ecology Mecopterans mostly inhabit moist environments although a few species are found in semi-desert habitats. Scorpionflies, family Panorpidae, generally live in broad-leaf woodlands with plentiful damp leaf litter. Snow scorpionflies, family Boreidae, appear in winter and are to be seen on snowfields and on moss; the larvae being able to jump like fleas. Hangingflies, family Bittacidae, occur in forests, grassland and caves with high moisture levels. They mostly breed among mosses, in leaf litter and other moist places, but their reproductive habits have been little studied, and at least one species, Nannochorista philpotti, has aquatic larvae. Adult mecopterans are mostly scavengers, feeding on decaying vegetation and the soft bodies of dead invertebrates. Panorpa raid spider webs to feed on trapped insects and even the spiders themselves, and hangingflies capture flies and moths with their specially modified legs. Some groups consume pollen, nectar, midge larvae, carrion and moss fragments. Most mecopterans live in moist environments; in hotter climates, the adults may therefore be active and visible only for short periods of the year. Mating behaviour Various courtship behaviours have been observed among mecopterans, with males often emitting pheromones to attract mates. The male may provide an edible gift such as a dead insect or a brown salivary secretion to the female. Some boreids have hook-like wings which the male uses to pick up and place the female on his back while copulating. Male panorpids vibrate their wings or even stridulate while approaching a female. Hangingflies (Bittacidae) provide a nuptial meal in the form of a captured insect prey, such as a caterpillar, bug, or fly. The male attracts a female with a pheromone from vesicles on his abdomen; he retracts these once a female is nearby, and presents her with the prey. While she evaluates the gift, he locates her genitalia with his. If she stays to eat the prey, his genitalia attach to hers, and the female lowers herself into an upside-down hanging position, and eats the prey while mating. Larger prey result in longer mating