Syrphus rectus

Adults can be distinguished from bees and wasps by: a single pair of wings (Hymenoptera have two pairs), very short antennae, and the presence of an extendable sponging mouthpart (proboscis) rather than chewing mandibles. The hovering flight behavior is characteristic—few bees are capable of sustained hovering. Within Syrphus, identification to species level requires examination of leg coloration and abdominal banding patterns; S. rectus is specifically associated with yellow legs. Final confirmation often requires examination of male genitalia or expert determination.

Gardens, agricultural fields, and natural areas with flowering plants and aphid populations. Associated with plants in the sunflower family (Asteraceae) where adults forage for nectar.

Eastern United States and southeastern Canada. Occasional records from Europe (likely vagrant or introduced).

Adults active from April through November in temperate regions.

Larvae are obligate predators of aphids. Adults feed on nectar from flowers, particularly those in the Asteraceae family.

• Aphids - preyLarvae feed exclusively on aphids; females lay eggs in or near aphid colonies.
• Asteraceae - adult food sourceAdults visit flowers for nectar.

Complete metamorphosis. Females lay eggs in or near aphid colonies. Larvae pass through three instars, feeding on aphids. Pupation occurs on leaves, stems, or other substrates as a convex, pear-shaped puparium. Adults emerge from the pupal case. Multiple generations per year likely in temperate regions given the extended flight period.

Adults exhibit characteristic hovering flight, often remaining stationary in mid-air. Females actively seek out aphid colonies for oviposition. Adults are diurnal and visit flowers for nectar. The species exhibits Batesian mimicry, with coloration and flight behavior resembling stinging Hymenoptera, which likely reduces predation pressure.

Biological control agent: larval predation on aphids helps suppress pest populations in agricultural and garden ecosystems. Adult pollination services through nectar foraging on Asteraceae and other flowering plants.

Beneficial insect in gardens and agriculture. Larvae provide natural biological control of aphid pests, reducing the need for chemical interventions. Adults are pollinators. Frequently mistaken for bees or wasps, which may lead to unnecessary concern or, conversely, accidental destruction of larvae during pest management activities.

• Syrphus opinatorClosely related congeneric species with similar black and yellow abdominal banding; requires careful examination of leg coloration and genitalia for definitive separation.
• Honey bees (Apis mellifera)Adults frequently mistaken for honey bees due to similar size, coloration, and flower-visiting behavior; distinguished by single pair of wings, short antennae, and hovering flight capability.
• Other Syrphus speciesMany Syrphus species share similar abdominal banding patterns; species-level identification requires examination of leg coloration, facial markings, and male genitalia.

Larvae are often mistaken for caterpillars or other plant-feeding larvae and may be inadvertently destroyed during gardening activities. The maggot-like appearance of larvae and their cryptic coloration (resembling discolored leaf patches or debris) contribute to this misidentification.

• hover fly
• flower fly
• aphid predator
• biological control
• pollinator
• mimicry
• beneficial insect

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Just Hovering | Bug Squad
• Hello, Friday Fly Day! | Bug Squad
• Bug Squad
• Syrphus-opinator - Entomology Today
• Bug Eric: The Maggot on the Rosebush: Aphid-eating Flower Fly Larvae
• New Website Features Insects of the Greater Yellowstone Ecosystem