Delta Journal
by Bob Thomas

Late spring ‘tis the time of year when those mysterious lovebugs are everywhere, especially spattered on the front of your car where they may clog the radiator, obscure vision or, if left too long, damage the paint with their acidic juices. Not only do they appear in great numbers in May, but lovebugs usually pop up again around September.

Members of the march fly family (Bibionidae), our local love or honeymoon “bugs” (Plecia nearctica), with their black bodies and red thoraxes, are among the more primitive flies. The adults feed on nectar in flowers and the larvae consume humus in the soil. Larvae may be very numerous and are often gregarious, being found in great numbers within a single cavity in the soil.

As might be imagined, lovebugs are very important ecologically as decomposers and as a relatively low link in the food chain. Several bird species are among the few predators on the adults, which are generally nasty to critters with taste buds. Fossorial larvae are preyed upon by soil creatures that normally feed on soft bodied species.

When the Central American native was described in 1940, it was thought to be restricted to coastal Louisiana and Texas. Over time, the range enlarged as the mating pairs were spread on the winds. With the advent of grass sod business, the larvae have been more widely distributed.

Lovebugs are so-called because they spend most of their early mornings and late afternoons hovering over areas where freshly metamorphosed adults are emerging. Females are grasped by males as they crawl up vegetation or immediately after launching on their maiden flights. Regardless of where the pairs come into contact, copulation is initiated on vegetation. Then comes the honeymoon flight which usually lasts for two to three days. During mating, the females do most of the flying and when she stops to feed on a flower, the male usually hangs off the side out of reach of the food, adding to his exhaustion from the experience! He usually dies while attached to his mate, and the union continues until the female lays her last egg.

After the pairs have separated, the females return to the soil to lay eggs and the cycle continues.

Lovebugs spend five to seven months in the soil as larvae, and only a couple of weeks as adults. Ah, but what a couple of weeks!