Often brightly coloured and with a distinctive hovering flight pattern, hoverflies are one of the most easily recognisable of the dipteran families. Some species are mimics of wasps and bees, which initially may cause some confusion, however careful observation of their behaviour and anatomy will confirm that they are flies (Diptera) and not Hymenoptera.
Hoverflies are the most widely recorded families of Diptera in the Outer Hebrides, however in comparison with other regions they are under-recorded. New species are still being added to the list for the islands and for many species knowledge of their distribution is very limited.
The diagnostic characteristic is the pattern of veins in the forewing and the presence of a vena spuria i.e., a spurious vein which cuts across the wing and is the reinforced hing of a longitudinal fold in the wing surface. There are also two outer cross veins which form a 'false margin' on the outer edge of the wing.
Some species can be readily identified in the field by close observation and some will need to be caught and examined in the hand, often with the aid of a hand lens. Unfortunately about half of the species on the British list need careful examination under a microscope (10x - 30x magnification) and the use of the keys and detailed descriptions in Stubbs & Falk.
Britain's Hoverflies is an excellent guide for field used and can be used to identify many of the species found in the Outer Hebrides.
|Baccha, Melanostoma, Platycheirus, Xanthandrus
|Chrysotoxum, Dasysyrphus, Didea, Doros, Epistrophe, Episyrphus, Eriozona, Eupeodes, Leucozona, Melangyna, Meligramma, Meliscaeva, Parasyrphus, Scaeva, Sphaerophotia, Syrphus, Xanthogramma
|Anasimyia, Eristalis, Eristalinus, Heliophilus, Lejops, Mallota, Myathropa, Parahelophilus
|Eumerus, Merodon, Psilota
|Blera, Brachypalpoides, Brachypalpus, Calliprobola, Chalcosyrphus, Criorhina, Pocota, Syritta, Tropidia, Xylota
|Heringia, Pipiza, Pipizella, Trichopsomyia, Triglyphus
|Cheilosia, Ferdinandea, Portevinia, Rhingia
|Brachyopa, Chrysogaster, Hammerschmidtia, Lejogaster, Myolepta, Neoascia, Orthonevra, Melanogaster, Ripponnensia, Sphegina