The love bug (also known as march fly, honeymoon fly, telephone bug, kissybug and double-headed bug) (scientific name Plecia nearctica) is a small flying insect common to the southern United States, especially along the Gulf Coast. It is most often known as a serious nuisance to motorists driving at high speeds when the insects spatter on their windshields in great numbers.

It was first described in 1940 by D. E. Hardy of Galveston, Texas. At that time, he reported the incidence of love bugs to be widespread, but most common in Texas and Louisiana. By the end of the 20th century, however, it had spread heavily to all areas bordering the Gulf of Mexico, as well as Georgia, South Carolina, and other parts of Central America. L. A. Hetrick, writing in 1970, found it very widespread in Florida and described its flights as reaching altitudes of 300 m to 450 m and extending several kilometers over the Gulf.

      Love bug swarms can number in the hundreds of thousands and blanket an entire small town in a dense cloud of insects. The thick swarming of these slow flying, almost drifting, insects almost is reminiscent of snow fall. The swarms occur twice each year, first in late spring, then again in late summer. The spring swarm occurs during late April and May. The summer swarm occurs during late August and September. Swarms extend over periods of 4 to 5 weeks. Mating takes place almost immediately after emergence of the females. Adult females live only 2-3 days.