Lovebugs, Plecia nearctica Hardy, are black colored flies with a reddish-orange thorax. They are in the family Bibionidae or March flies and like all true flies they have one pair of wings as adults. The common name “lovebugs” has been given to these flies because they often fly while still coupled during mating. Adult lovebugs emerge after rainy periods and can be abundant locally. They are a nuisance when smashed on car windshields and headlights or when they interfere with house painting and other human activities.
Adult lovebugs are about 3/8-inch long with a pair of smoky colored wings. Larvae or maggots grow to about 3/8 inch long and are slate-gray in color with dark heads. Other March flies in Texas are generally black with clear wings and are seldom abundant, even locally. All March flies are weak fliers.
Adult lovebugs typically emerge in large numbers primarily in the spring (May) and autumn (September). The autumn emergence is usually larger. The female is larger than the male and the female will fly off dragging the attached male. Although individual females live for only a week or so, adult flight activity lasts for a period of about 4 or more weeks as new adults emerge.
Eggs are deposited in swampy areas and ditches. The resulting larvae develop through several stages (instars) reaching a length of about 3/8 inch. Larvae are seldom encountered but they can be found in the soil in moist edges along waterways rich in organic matter. Larvae sometimes can be found in well-watered lawns with an accumulation of thatch. Pupae are found in the soil and emerge as adults in about 8 days.
Lovebug larvae develop in moist habitats high in organic matter such as ditches and swampy areas. Larvae have chewing mouthparts and feed on decomposing organic matter and sometimes plant roots. They are harmless as immatures and are actually beneficial by decomposing plant tissues.
Adults emerge during specific times of the year usually after the soil has been saturated for prolonged periods. Adults fly mainly during daylight hours and spend time sipping nectar from flowers and mating. They are naturally attracted to open or semi-open areas such as roadways and ditches often in areas with woods. They sometimes accumulate around gas stations, fresh tar and wet paint. It is generally believed that car exhaust and/or gasoline contains some attractants for these flies. They also appear to be attracted more to white or light colored cars than dark ones.
Both adult and immature lovebugs are considered medically harmless. However, the presence of lovebugs in large numbers can be quite a nuisance. Large numbers of lovebugs in flight over roadways can cause bug-splattered windows and clogged radiator grills. Insects splattered on windshields can obscure vision, and if the dead insects are not cleaned off promptly, they can ruin the finish on a car. Clogged radiators can cause engine overheating.
There is no easy solution to lovebug problems. It may be necessary to learn to cope with lovebugs with a variety of methods for a few weeks each year. The following facts and suggestions will help:
- Lovebugs do not fly at night or during cool weather, so driving schedules can sometimes be arranged to avoid peak lovebug flight activity.
- Fewer flies are smeared over car finishes if vehicles are driven at lower speeds. Some commercially available wind deflectors positioned on the front hood of cars and trucks may help deflect flies and keep them from hitting the windshield.
- Netting stretched over front grills can prevent crushed flies from clogging radiators and thus prevent overheating on long trips. Some netting devices are commercially available.
- Daily cleaning of a vehicle will help protect the finish and prevent a build-up of lovebug bodies on engine parts. Commercially available products containing petroleum distillates can facilitate the removal of crushed, dried insect parts from car finishes.
- Chemical control of lovebug maggots is not recommended because they are basically harmless and the semiaquatic habitat of the larvae is an environmentally sensitive area.
- Adult lovebugs can fly well enough to make treating a large enough area to reduce the local population impractical.
- Foggers and aerosol insecticides designed for quick knock down of adult lovebugs may provide temporary relief from flying adults. However, compounds used in foggers disperse readily and therefore effectiveness is soon lost. Lovebug flights may last for several weeks, so multiple treatments with foggers would be required for relief throughout the flight periods.
- Lovebugs do not respond to insect repellents containing DEET or citronella.
- Adult lovebug numbers may be drastically reduced by heavy rains.
- Lovebug flight periods are temporary. Avoid house painting when lovebugs are active.
- Lovebugs do not bite or sting.
A persistent rumor exists that Texas A&M and other universities have imported lovebugs for research on fly and mosquito control. Lovebugs are native Texas insects that were first described by Hardy in 1940 from Galveston, Texas. They occur naturally all along the Gulf Coast from Texas to Florida.
This publication replaces UC – 009.
Suggested pesticides must be registered and labeled for use by the Environmental Protection Agency and the Texas Department of Agriculture. The status of pesticide label clearances is subject to change and may have changed since this publication was printed.
The USER is always responsible for the effects of pesticide residues on his/her livestock and crops, as well as problems that could arise from drift or movement of the pesticide from his/her property to that of others. Always read and follow carefully the instructions on the container label.
The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Cooperative Extension is implied. Educational programs conducted by the Texas Cooperative Extension are open to all people without regard to race, color, sex, disability, religion, age or national origin.