Female march fly

Bibionid larvae grow up in grassy areas and are herbivores and scavengers feeding on dead vegetation or living plant roots. Some species are found in compost . Adults of Plecia and some species of Bibio do not eat, but subsist solely on the food taken in during the larval stage. Adult stage bibionids are quite short-lived, and some species of Plecia (lovebugs) spend much of their adult lifetime copulating. The slow-flying male and female attach themselves at the rear of the abdomen and remain that way at all times, even in flight. Adults swarm after synchronous emergence, sometimes in enormous numbers.