In south Florida, a third (but smaller) flight can occur in December.
This species' reputation as a public nuisance is due not to any bite or sting (it is incapable of either), but to its slightly acidic body chemistry.
Their body chemistry has a nearly neutral 6.5 p H but may become acidic at 4.25 p H if left on the car for a day.
However, advances in automotive paints and protective coatings have reduced this threat significantly.
Now the greatest concern is excessive clogging of vehicle radiator air passages with the bodies of the adults, with the reduction of the cooling effect on engines, and the obstruction of windshields when the remains of the adults and egg masses are smeared on the glass.
The lovebug, Plecia nearctica, is a member of the family of march flies.
It is also known as the honeymoon fly, kissingbug, or double-headed bug.
The adult is a small, flying insect common to parts of Central America and the southeastern United States, especially along the Gulf Coast. Hetrick, writing in 1970, found the bug was also widespread in central and northern Florida and described its flights as reaching altitudes of 300 to 450 metres (980 to 1,480 ft) and extending several kilometers over the Gulf.
However, by the end of the 20th century the species had spread heavily to all areas bordering the Gulf of Mexico, as well as Georgia and South Carolina. Immature lovebugs' larvae feed on partially decayed vegetation in the landscape and, in this respect, are beneficial.
Adults primarily feed on nectar from various plants, particularly sweet clover, goldenrod, and Brazilian pepper.
Localized lovebug flights can number in the hundreds of thousands.
The slow, drifting movement of the insects is almost reminiscent of snow fall except that the flies also rise in the air.
Two major flights occur each year, first in late spring, then again in late summer.