Marmalade Hoverfly

• It is a long-distance migrant: every year hundreds of millions of individuals cross the Pyrenees and the Alps in a flow comparable to that of migratory birds, something only quantified in recent decades.
• Its resemblance to a wasp is pure bluff: it has no sting and so cannot sting, and protects itself solely by mimicking a dangerous insect.
• As a pollinator and as a predator of aphids it is one of the most useful insects in European agriculture, and the flower strips sown in crops are designed in good measure with it in mind.
• It is a fly dressed up as a wasp: its black-and-yellow bands are pure Batesian mimicry. It has no sting and cannot sting.
• Telling it apart is easy if you know what to look for: it has two wings instead of four, enormous eyes that take up almost the whole head, and extremely short antennae.
• It hovers, hanging motionless in mid-air, which is where the name hoverfly comes from. It can hold perfectly still and then dart sideways in an instant.
• Its larva is a voracious predator of aphids: each one can consume several hundred before pupating, which makes it one of the most valuable allies of horticulture.
• It is a migrant, and a long-distance one: it has been estimated that billions of hoverflies cross southern England every year on seasonal migration, carrying pollen over enormous distances and providing a pollination and pest-control service on a continental scale.
• The adults are important pollinators, above all of umbellifers and composites.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat and environment

Gardens, crops, meadows and roadsides throughout Europe

Size at birth

White egg laid within the aphid colony; a single larva consumes several hundred aphids during its two weeks of feeding

Sexual maturity

The species combines three overwintering strategies: migration, local overwintering in the pre-adult stage and local overwintering as an adult, with no genetic differentiation between them

Gestation / incubation

The eggs hatch after 6-8 days; the larva feeds for about two weeks and the pupa lasts 5 to 14 days, in the soil or attached to a stem

Litter / clutch size

Between 2,000 and 4,500 eggs per female over her adult life, laid one by one directly within the aphid colonies

Sources consulted: Wotton et al. (2019), Current Biology · Buglife · Rotheray y Gilbert, The Natural History of Hoverflies · Arthropoda Fotos, ficha Episyrphus balteatus · Fichas de especie de Episyrphus balteatus · Ficha de especie de Episyrphus balteatus · NCBI PMC3759392, estrategias de invernada de Episyrphus balteatus

Best time: Spring to autumn, peaking during the migrations