HoverfliesInteresting facts and information

• A hoverfly can resemble a wasp without having a sting. In many species, yellow-and-black markings mimic the appearance of stinging insects.
• It has only two wings used for flight. Bees and wasps have two pairs, making four wings.
• Adults and larvae can play different roles in nature. Adults visit flowers, while the larvae of some species hunt aphids or help break down organic remains.
• Some hoverflies migrate. They do not all stay in the garden where we see them during summer.
• The family also occurs in Romania. The Grigore Antipa National Museum of Natural History holds an important scientific collection of these insects.

Small size does not stop some hoverflies from carrying pollen over long distances. A study published in 2025 examined Episyrphus balteatus that reached an offshore platform in the North Sea, approximately 200 km from the Scottish coast.

Researchers found pollen on most of the insects examined. Using the pollen and wind patterns, they estimated that many had come from regions more than 500 km away. This was an estimate of their origins, not a direct measurement of each fly's route.

Hoverflies are also remarkably diverse: their family includes more than 6,000 described species worldwide, according to the IUCN specialist group. Their flight, colours and larval diets vary greatly, so no single example represents them all.

Hoverflies belong to the order Diptera, alongside other flies and mosquitoes. They have six legs, antennae and large compound eyes made up of many small units that receive light.

Colour alone is not enough for identification. Some hoverflies mimic bees, others bumblebees or wasps. Wing number and antenna shape offer useful clues, but exact identification may require a specialist.

Resembling an insect with a defensive weapon is a form of mimicry. It may reduce the chance of a predator attacking the hoverfly. This differs from camouflage that blends an animal into leaves or bark.

Hovering is one of their most noticeable abilities. A hoverfly may stay in one spot for a few moments, then quickly change position or land on a flower.

Adults are often seen by day on flowers and vegetation. Their behaviour depends on the species, temperature and weather. An activity period described for Britain is not an exact calendar for Romania or elsewhere.

Some species, including Episyrphus balteatus, make migratory journeys. Research shows that these movements also have an ecological role: the insects can carry pollen between regions.

Other hoverflies are more closely tied to a particular habitat. If their larvae need wet wood or a host plant, flowers for adults alone cannot meet their needs throughout life.

Hoverflies occur on every continent except Antarctica. This is the range of the family as a whole; each species occupies only part of that area.

Many hoverflies are documented in Romania. The Vladimir Brădescu collection at the Grigore Antipa National Museum of Natural History includes specimens from Romania and other European regions.

• Gardens, parks and farmland: many species find flowers and, for predatory larvae, colonies of aphids.
• Meadows and woodland edges: these provide varied plants and sunny places.
• Woodland with old trees: some larvae depend on decaying wood and damp cavities.
• Wetlands: certain species have aquatic larvae adapted to water rich in organic matter.

These needs explain why not all hoverflies benefit from the same measures. A patch of flowers helps adults, while retaining larval habitats provides another essential resource.

Adults mainly eat nectar and pollen. Nectar supplies energy, while pollen is an important source of nutrients. Many hoverflies visit open flowers where food is easy to reach.

Pollen may stick to an insect's body during a visit. When it reaches the receptive part of another flower of the same plant species, the insect contributes to pollination. Not every contact or flower visit achieves this.

Not all hoverfly larvae eat aphids. Nor does the presence of adults guarantee that aphids will disappear from a garden. The benefit depends on the species present and local conditions.

In predatory species, females may lay eggs near an aphid colony. The larvae then have food nearby when they hatch.

Hoverflies undergo complete metamorphosis: egg, larva, pupa and adult. A larva looks different from an adult fly and has no wings or obvious jointed legs.

Some aquatic larvae, such as those of Eristalis tenax, have a long breathing tube. This lets them take in air at the surface while their body remains underwater.

The duration of each stage and the way they overwinter vary between species. Some can overwinter as adults. There is no single lifespan for the whole family. Temperature and resources influence their development.

The name hoverfly refers to the ability to remain in one place in the air. They are also called flower flies because of their visits to flowers. Both names refer to flies in the family Syrphidae.

Romanian entomologists have also studied hoverflies. Vladimir Brădescu donated most of his collection to the Grigore Antipa Museum in 1986. It remains an important resource for research on these flies in Romania.

Museum specimens help specialists compare body structures and check identifications. Field observations and photographs provide additional information about distribution and activity.

Hoverflies do not share a single conservation status. Some species are widespread, while others are threatened. The European IUCN assessment published in 2022 highlighted serious risks to this group.

• Habitat loss reduces flowers, host plants and places where larvae develop.
• Removing old trees and decaying wood affects species that depend on these resources.
• Pesticide use can affect the insects and their food supplies.
• Climate change alters habitats and conditions for development.

In gardens, useful measures include open flowers that bloom at different times, a less disturbed patch of vegetation and avoiding unnecessary insecticide use. Keeping dead wood in suitable places also matters for some species.

Hoverflies are among the pollinating insects, alongside bees, bumblebees and the hummingbird hawk-moth.

• Is a hoverfly a bee or a wasp? No. It is a fly in the family Syrphidae. Many species mimic the colours of bees or wasps.
• Do hoverflies sting? No. Hoverflies have no venomous sting and do not sting.
• How many wings does a hoverfly have? One pair used for flight, unlike the two pairs found in bees and wasps.
• What do hoverflies eat? Adults mainly eat nectar and pollen. Larval diets vary between species.
• Do all hoverfly larvae eat aphids? No. Some are predators, while others feed on plants or material associated with decaying organic matter.
• Are hoverflies found in Romania? Yes. They are documented in Romania's fauna and in the scientific collections of the Grigore Antipa Museum.
• Why are hoverflies useful? Adults help pollinate plants. Some larvae eat aphids, while others help break down organic remains.
• Do all hoverflies migrate? No. Migration is documented in certain species, such as Episyrphus balteatus, and is not a feature of the entire family.