Lovebug vs Fungus gnat

These two are easy to mix up. Here's how to tell a lovebug from a fungus gnat, and whether either one bites or stings.

Fungus gnat

Bradysia coprophila

Fungus gnats are more delicate, longer-legged and not typically seen in persistent mating pairs or large daytime swarms.

	Lovebug	Fungus gnat
To humans	Non-toxic	Non-toxic
Size	6-8 mm body length (typical)	2-4 mm long
Colours	Black, Red-orange, Smoky wing	Black, Dark gray, Brown
Family	Bibionidae	Sciaridae
Habitat	Moist grassy areas, roadside verges, gardens with compost or heavy leaf litter, and nearby soils where larvae develop.	Moist, organic-rich soils, potted plants, greenhouses, compost, decaying plant material
Range	Native to Central America; established and common in the southeastern United States and Gulf Coast states, with range expansions northward and inland in recent decades.	Cosmopolitan in temperate regions; common wherever potted plants, greenhouses or decaying organic matter provide habitat
Active	Two annual peaks: spring (often April-May) and late summer (often August-September) in the southeastern United States; adults fly during daylight hours.	Year-round in heated greenhouses and indoors; spring to fall outdoors in temperate regions, most active in warm, damp conditions and at dusk
Pest?	No	Yes

Small humpbacked black fly with a distinct red-orange thorax in many individuals.
Adults commonly seen in mating pairs glued together end-to-end while flying.
Active in large swarms during two seasonal peaks (spring and late summer) in affected regions.

Adults are 2-4 mm long, slender, dark-bodied flies with long legs and long multi-segmented antennae.
Larvae are white or translucent maggots with a dark head capsule, found in the top 1-3 cm of moist potting soil.
Adults are weak fliers and often seen walking on soil or flying low in swarms near plants or lights.
Species-level separation from other sciarids requires microscopic examination of adult genitalia; look for general sciarid morphology for field ID.

Fungus gnats are more delicate, longer-legged and not typically seen in persistent mating pairs or large daytime swarms.

Lovebug: Non-toxic. Fungus gnat: Non-toxic. Lovebugs do not bite or sting and are not venomous. Adults do not bite or sting.

Identification from photos is never certain: don't handle insects you can't identify, and get medical advice for bites, stings or allergic reactions.