Semaphore Fly

Poecilobothrus nobilitatus · Order: Diptera · Family: Dolichopodidae

No source yet on danger. We have no source yet on whether it bites, stings or damages anything.
Semaphore Fly
Photo: gailhampshire from Cradley, Malvern, U.K, CC BY 2.0

The Semaphore Fly is a small metallic green fly about 7 mm long, with smoky black wings that turn white at the tips. It lives around ponds and wetlands in many European countries and hunts small aquatic creatures on the water surface.

Source: Wikipedia

How to recognize it

Males have smoky black coloration on the outer half of their wings and white tips, while their bodies shine golden-green.

Source: Wikipedia

Size

Adults measure roughly 7 mm in length.

Source: Wikipedia

Where it lives

They are found near ponds and other wetland areas where they hunt and mate.

Source: Wikipedia

Life cycle

Mating requires the female to cooperate after the male’s courtship display. Males have a prominent, movable hypopygium that bends the abdomen to start copulation.

Source: Wikipedia

When you see it

Their mating behavior is well studied because of distinctive mate-selection rituals, and females tend to choose larger males.

Source: Wikipedia

Lookalikes

Many Dolichopodidae flies show metallic green reflections in their eyes due to wavelength-selective corneal reflectance, and the family shows great diversity in male signaling organs.

Source: Wikipedia

More photos

Semaphore Fly photo 3
Photo: kitenet, CC BY 2.0
Semaphore Fly photo 4
Photo: Bj.schoenmakers, CC0
Semaphore Fly photo 5
Photo: kitenet, CC BY 2.0
Semaphore Fly photo 6
Photo: gailhampshire from Cradley, Malvern, U.K, CC BY 2.0

Same family (Dolichopodidae)

Long-legged flyLong-legged flyCondylostylus longicornisCondylostylus patibulatusCondylostylus patibulatusCondylostylus patibulatus

Sources

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

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

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

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