The Love Bug, Plecia nearctica, is a species of march fly recognized for flying in coupled pairs. Despite appearing in large seasonal swarms, Love Bugs do not eat mosquitoes; their feeding habits are entirely non-predatory. This small, black fly with a red thorax belongs to the family Bibionidae, making it more closely related to house flies and gnats than to predatory insects.
The Actual Diet of Love Bugs
The Love Bug’s diet is based on scavenging and nectar consumption, placing it firmly in the category of non-hunters. The larval stage, which is the longest part of its life cycle, is spent beneath the soil feeding on decaying organic material. Larvae consume decomposing plant matter such as leaf litter, grass clippings, and other dead vegetation. This feeding behavior is beneficial, aiding in the process of decomposition and the recycling of nutrients back into the soil.
Adult Love Bugs primarily feed on nectar and other sugary substances, such as plant sap. They are often seen feeding on the nectar and pollen of flowers like sweet clover and goldenrod. The adults’ lifespan is quite short, typically lasting only a few days, and their main focus is mating rather than extensive feeding. The Love Bug’s mouthparts are not structured for capturing and consuming other insects, reinforcing their non-predatory role.
Natural Predators of Mosquitoes
Since Love Bugs do not control mosquito populations, it is important to understand which organisms perform this function. Mosquitoes are preyed upon during both their aquatic larval stage and their flying adult stage. The aquatic phase sees larvae consumed by fish, such as the Gambusia affinis (mosquito fish), as well as by tadpoles and certain aquatic insects.
Dragonflies and damselflies are significant predators in both life stages. Their aquatic nymphs, often called “mosquito hawks,” actively hunt mosquito larvae in the water. Once mature, adult dragonflies are agile flyers that catch adult mosquitoes in the air, helping to reduce the population of biting females. Other natural controls include bats and certain species of birds, which consume large numbers of adult mosquitoes around dusk.
Ecological Nuisance and Life Cycle
Love Bugs typically have two major emergence periods each year, one in late spring and another in late summer or early fall. These periods correspond to their mating seasons, where adult males emerge first and swarm over emergence areas to await the females. The male and female remain coupled together, often for several days, even while flying.
The immense swarms of Love Bugs create a nuisance for humans, particularly motorists. They are strongly attracted to the odors of vehicle exhaust and the heat from engines, causing them to congregate along highways. When vehicles travel at high speeds, the insects splatter on windshields and radiator grilles, potentially obstructing visibility and causing engines to overheat. The body fluids of the smashed insects are slightly acidic and can damage a vehicle’s paint if not washed off within a few days.