Lovebug

Bibio femoratus · Order: Diptera · Family: Bibionidae

No source yet on danger. We have no source yet on whether it bites, stings or damages anything.
Lovebug
Photo: Christian Back, CC BY

Lovebugs are medium-sized flies with a dark abdomen and bright red or orange thorax and legs. Adults emerge together in early spring, form large swarms, and feed on liquids like water or nectar while the larvae live in decaying plant material during fall and winter.

Source: Wikipedia

How to recognize it

They have a dark brown to black long abdomen and red or orange thorax and legs. A dark spot appears on the leading edge of the first wing about two-thirds of the way from the body.

Source: Wikipedia

Size

Body length ranges from about three-eighths to one and a quarter inches.

Source: Wikipedia

Is it a pest in the house?

They are named for their bright red femurs and tend to ignore human movement.

Source: Wikipedia

Where it lives

Adults are usually seen a few feet above the ground. Larvae feed on decaying plant matter, sometimes including grass roots.

Source: Wikipedia

What it eats

Adults sip liquids such as water or nectar. Larvae consume decaying organic material.

Source: Wikipedia

Life cycle

Larvae develop in fall and winter, feeding on decaying organic matter. Adults emerge synchronously and form large mating swarms.

Source: Wikipedia

When you see it

Adults are most abundant in early spring after a synchronized emergence.

Source: Wikipedia

Where it comes from

They occur throughout the United States and Canada.

Source: Wikipedia

Lookalikes

Lovebugs belong to a group of over 90 March fly species and are also called March flies.

Source: Wikipedia

Where it is found in the US

Recorded in 33 of 51 states and DC. Most records: Massachusetts, New York, Virginia, Pennsylvania, Maryland, North Carolina, Michigan, Connecticut.

Darker = more records. Counts are museum and citizen-science records, not population size.

Source: GBIF

Status: native in North America; native in Canada; native in United States. Source: iNaturalist

Months it is reported in the US

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Source: GBIF

More photos

Questions people ask

When do lovebugs appear?

Adults appear in early spring after a synchronized emergence and can be seen in large swarms.

Source: Wikipedia

What do lovebug larvae eat?

The larvae feed on decaying plant matter, sometimes including grass roots.

Source: Wikipedia

Same family (Bibionidae)

Sources

  • Wikipedia: https://en.wikipedia.org/wiki/Bibio_femoratus

Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia

Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.

How this page works

This is one bug's fact sheet. The colored box at the top says whether it is dangerous. Sections below cover how to recognize it, whether it is a pest, and how to deal with it. The US map shows which states have records; tap a state to see other bugs there.

Every fact on Bug FAQ comes from a named source (university extension sites, government agencies, GBIF, iNaturalist, Wikipedia). The source is linked next to each section. If we have no source for something, we leave it out.