Animal

Hoverfly

Also known as: syrphid fly, flower fly, Syrphidae

Family of true flies (Diptera: Syrphidae) whose adults visit flowers (mimicking bees and wasps for predator protection) and feed on pollen and nectar, while their larvae are voracious aphid predators. One of the most important non-bee pollinators in temperate gardens and one of the most underrated biological pest-control allies. A single hoverfly larva consumes 200–400 aphids before pupating; a healthy garden population can keep aphid pressure manageable without insecticide intervention.

Most gardeners learn to recognize bees and butterflies. Far fewer learn to recognize hoverflies — and miss one of the most valuable insects in their garden. Hoverflies (Syrphidae) hover in place over flowers, often striped yellow-and-black like wasps or bees but with the characteristic dipteran two wings, large eyes, and stationary hovering flight. Their larvae — small, slug-like, often green or brown — are among the most effective aphid predators in temperate ecosystems.

What the adults do

Adult hoverflies feed on pollen and nectar. They are among the top three groups of non-bee pollinators globally, contributing meaningfully to pollination of:

Brassicas (cabbage, broccoli, kale, mustards)
Apiaceae (carrot, dill, parsley, coriander, fennel)
Asteraceae (lettuce, sunflower, cosmos, daisies)
Many wild and orchard plants

They are particularly active in cool weather when bees are inactive — early spring, late fall, cooler mornings and evenings.

What the larvae do

Each hoverfly larva consumes 200–400 aphids during its 1–2 weeks of larval development. The female adult deliberately lays eggs near aphid colonies; the emerging larvae move through the colony eating aphids one after another. They also eat:

Small caterpillars (especially newly-hatched)
Mealybugs
Thrips
Whitefly nymphs

A garden with a healthy hoverfly population rarely has the kind of catastrophic aphid outbreaks that occur in chemical-controlled gardens (where the broad-spectrum pesticide kills the beneficials along with the pest, and the aphids recover faster than their predators).

How to attract them

Hoverflies want:

Small flowers with accessible nectar — they have short mouthparts; tubular flowers don’t work for them
Umbel-form flowers — dill, fennel, cilantro (let some bolt), carrot (let some flower), Queen Anne’s lace, sweet alyssum
Composite flowers — daisies, cosmos, marigolds (single-flower forms, not doubles), calendula
Some unmown areas — they shelter in long grass and unmanaged edges
No insecticides — adult hoverflies are killed by most pyrethrum, neonic, and synthetic-pesticide applications

A simple practice: let a small section of your dill, cilantro, parsley, or carrots flower each year. The hoverfly population will respond within weeks.

How to recognize them

Hovering — they hover stationary in place; bees do not
Two wings (not four) — diagnostic for flies vs. bees and wasps
Large eyes filling much of the head
Stripe pattern mimicking bees or wasps, but no narrow waist
No stinger — they cannot sting

Sources

Syrphidae of the Pacific Northwest (Oregon State University Press)
Helen Sullivan, The Pollinators: Native Bees and Other Insects in Gardens and Farms — chapter on syrphid pollinators
USDA Forest Service publications on beneficial insects

Rooted in life.

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Practical

shares approach with

Predatory Wasp both are aphid-and-caterpillar biological controls; parasitoid wasps target specific pest species, hoverfly larvae are more generalist

1 inbound link · 3 outbound