Insects & other Arthropods David A Kendall   BSc PhD
Order Diptera (True Flies)
(Di-ptera, from Greek dis = two, pteron= wing)
Class: Insecta

Small to moderate-sized insects in which the hindwings are reduced to club-shaped balancing organs or halteres, leaving only one pair of membranous wings. A few species are completely wingless, usually in association with parasitic habits. Eyes usually large, occupying much of the head. Antennae variable, sometimes long and thread-like or plumose, but more often fairly short and bulbous, with the terminal segments more or less fused to form a spur or bristle. Mouthparts in the form of a proboscis for sucking liquid food, and sometimes also adapted for piercing. Many flies resemble bees and wasps as a result of mimicry, but such resemblances are only superficial (in body shape and colour, for example) and close examination will reveal only one pair wings, indicating a true fly (bees and wasps have two pairs of wings). There is a complex metamorphosis, with 3-8 larval stages, depending on species, and a pupal stage. Larvae are legless maggots, with the head reduced and often retracted into the body. The pupae of many Diptera remain enclosed within the last larval skin, which hardens to form a protective outer shell or puparium. The true flies make up a very large Order with somewhere around 90,000 known species worldwide, of which some 5,200 are found in the British Isles. The flies have exploited a very wide range of food materials, from decaying plant or animal matter on the one hand to nectar or blood on the other, and the Order as a whole is of considerable economic importance. Species that feed on decaying matter perform a useful scavenging role in the re-cycling of organic nutrients, others are useful predators or parasites of aphids and other plant pests, while many flower-feeding species are valuable pollinators. A number of flies are themselves agricultural pests in their larval stages and sometimes cause severe crop losses, but it is for direct attacks on man and his livestock that flies are most important. Blood-sucking flies are found in many families and they carry several dangerous diseases, including malaria, sleeping sickness, yellow fever and elephantiasis. Veterinary pests include a number of species whose maggots eat away or burrow into the flesh of domestic sheep and cattle, causing the condition known as myiasis.

Sub-order Nematocera (Crane-flies, Black-flies, Gnats, Midges & Mosquitoes) Top  |  Home Page
Tipula pagana (male & female)
Tipula pagana - a Crane-fly (male & female mating)
b. 11-16 mm
Tipula pagana (male)
Tipula pagana - a Crane-fly (male)
b. 11-16 mm (detail of body & wings)
Tipula pagana (female)
Tipula pagana - a Crane-fly (female)
b. 11-16 mm (detail of body & vestigial wings)
Tipula paludosa (male & female)
Tipula paludosa - a Crane-fly (male & female)
b. 20-30 mm (Photo: J. Weir)
Tipula vittata (female)
Tipula vittata - a Crane-fly (female)
b. 20-25 mm
Crane-fly larvae (Leatherjackets)
Tipula sp. - Crane-fly larvae (Leatherjackets)
b. up to 50 mm
St Mark's-fly
Bibio marci - St Mark's-fly
b. 10-15 mm (Photo: T. Taylor)
Psychodidae - a Moth-fly, Owl-midge or Drain-fly
b. 3-4 mm (Photo: A. Ferguson)
Sub-order Brachycera (Horse-flies, Bee-flies, Soldier-flies, Robber-flies, etc.) Top  |  Home Page
Tabanus sp.
Tabanus sp. - a Horse-fly
b. 15-20 mm (Photo: K. Leach)
Bombylius major - Bee-fly
b. 10-12 mm (Photo: M. Short)
Sub-order Cyclorrhapha, Series Aschiza (Hover-flies, Scuttle-flies, etc.) Top  |  Home Page
Eristalis intricarius
Eristalis intricarius - a Hover-fly
b. 9-12 mm
Eristalis pertinax
Eristalis pertinax - a Hover-fly
b. 10-14 mm
Drone Fly
Eristalis tenax - Drone Fly
b. 10-15 mm
Myathropa florea
Myathropa florea - a Hover-fly
b. 8-12 mm
Helophilus sp.
Helophilus sp. - a Hover-fly
b. 14-16 mm
Volucella zonaria
Volucella zonaria - a Hover-fly
b. 16-20 mm
Merodon equestris - Narcissus-fly
b. 12-15 mm
Syrphus ribesii
Syrphus ribesii - a Hover-fly
b. 12-15 mm
Episyrphus balteatus
Episyrphus balteatus - a Hover-fly
b. 10-12 mm
Scaeva pyrastri
Scaeva pyrastri - a Hover-fly
b. 12-15 mm
Sphaerophoria sp.
Sphaerophoria sp. - a Hover-fly
b. 10-12 mm
Melanostoma or Platycheirus sp.
Melanostoma or Platycheirus sp. - a Hover-fly
b. 8-10 mm
Sub-order Cyclorrhapha, Series Schizophora (Fruit-flies, Blow-flies, etc.) Top  |  Home Page
Holly Leaf Miner (larval mine on holly)
Phytomyza ilicis - Holly Leaf Miner
(larval mine on holly)
Calliphora sp.
Calliphora sp. - a Blow-fly or Bluebottle
b. 8-12 mm
Yellow Dung-fly
Scathophaga stercoraria - Yellow Dung-fly
b. 8-9 mm
Sarcophaga sp. - Flesh-fly
b. 12-16 mm
Stenepteryx hirundinis - Louse-fly (a parasite of birds)
b. circa 5 mm (Photo: T. L. Knowles)
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Copyright © 2014 David Kendall