DIPTERA > BRACHYCERA | Higher Diptera

LOWER BRACHYCERA > ASILOMORPHA > Asiloidea > Asilidae (29 species)

(subfamilies: Asilinae, Dasypogoninae, Laphriinae, Leptogasterinae and Stenopogoninae)

I have to admit that when I first started looking at the various fly families, Asilidae immediately grabbed my attention simply because of the common name robberflies. Purely from a photographic angle, a species tussling with prey is generally going to have a lot more interest than one sitting on a leaf!

Adult robberflies are most active during late morning or early afternoon on hot sunny days in the summer when they may be found waiting to pounce on unsuspecting prey, which may include species from all the common insect orders. Whereas most species of robberfly prefer sitting in the sun in sheltered spots, either on exposed sand or soil or on posts, logs and stones, others hunt on the wing. With their liking for warm weather, most species have a predominantly southern distribution.

All species have been given a common name and all are well covered in the ‘British Soldierflies and their Allies’ guide, although quite a few are difficult to positively id from photos.

General characteristics confirm that most species fall within a medium to large size range (8-20mm) whilst a few will be smaller, and one particularly, Asilus crabroniformes, much larger; body shape varies from long and slender to short and stout; colour and pubescence also varies across the species from dark metallic lustrous to paler, with orange or yellow markings - some resembling bees or wasps; head dorsally concave between their dichoptic separated eyes in both sexes; prominent bristles on the face, named the mystax or beard; powerful forward or downward projecting proboscis; wings usually clear, although in some cases completely or partially tinged; legs long and powerful often armed with strong bristles.

New photos added, Dec.24 (v.4)