Richard Du Toit / Burchell's Zebra (Equus burchellii) reacting to parasitic Bot Fly (Oestridae) trying to lay eggs on it, KwaZulu-Natal, South Africa

Konrad Wothe / Fly (Gymnosoma rotundatum) Bavaria, Germany. June.

Philippe Clement / Parasite fly / tachinid fly (Tachina fera) feeding on nectar from Hogweed (Heracleum sphondylium) in summer, France. August.

Naskrecki & Guyton / Parasitic fly (Raymondia sp.) on fur of Horseshoe bat (Rhinolophus mossambicus) from Gorongosa National Park, Mozambique

Naskrecki & Guyton / Parasitic fly (Raymondia sp.) on the wing membrane of the Horseshoe bat (Rhinolophus mossambicus) from Gorongosa National Park, Mozambique

Piotr Naskrecki / Wingless Bat Fly (Penicillidia sp) on Lesser Long-fingered Bat (Miniopterus fraterculus), Gorongosa National Park, Mozambique

Piotr Naskrecki / Wingless Bat Fly (Penicillidia sp) on head of Long-winged Bat (Miniopterus mossambicus), Gorongosa National Park, Mozambique

Piotr Naskrecki / Lesser long-fingered bat (Miniopterus fraterculus, Miniopteridae) in flight, with a parasitic wingless fly (Penicillidia sp, *** Bent-winged bat (Miniopterus) in flight, with Bat fly (Penicillidia) in...

Bernard Castelein / Fly (Eriothrix rufomaculata), KLein Schietveld, Brasschaat, Belgium. June

Rod Williams / Ladybird fly (Gymnosoma rotundatum) a rare / localised species Brockley Cemetery, Lewisham, London, England, UK. May.

Jiri Lochman / Snail parasite blowfly (Amenia imperialis) Cape Tribulation, North-eastern Queensland, Australia.

Andy Sands / Tachnid fly (Phasia hemiptera) male, the female lays its eggs directly onto Forest Bugs and Green Shield Bugs where the larvae live as parasites, Hertfordshire, England, August

Andy Sands / Tachnid fly (Phasia hemiptera) male, the female lays its eggs directly onto Forest Bugs and Green Shield Bugs where the larvae live as parasites, Hertfordshire, England, August

Paul Bertner / Fruit Fly (Tephritidae) pair mating, with mite on back, Gunung Leuser National Park, Sumatra, Indonesia

Paul Bertner / Fruit Fly (Tephritidae) with fungal infection, Ankarafantsika National Park, Madagascar

Rod Williams / Parasitic fly (Conops quadrifasciatus) parasite of Red-tailed Bumblebee Brockley cemetery, Lewisham, South East London, England, UK, August.

Kim Taylor / Parasite fly (Tachina fera) on Eryngium. Surrey, England, UK, August.

Kim Taylor / Tachinid fly (Dexiosoma caninum). Surrey, England

Nick Upton / Tachinid fly (Nowickia ferox) with worn wings, chalk grassland meadow, Wiltshire, UK, July.

Andy Sands / Tachnid fly (Phyllomya volvulus) Resting on leaf after rain shower, Oxfordshire, England, UK, June

Andy Sands / Conopid fly (Sicus ferrugineus) parasitic fly whose larvae are endoparasites on various species of Bumblebee, Oxfordshire, England, UK, June

John Abbott / Tachinid or Parasitic fly (Epalpus signifer) flying Travis County, Texas, USA. Controlled conditions. September

John Abbott / Tachinid or parasitic fly (Epalpus signifer) flying Travis County, Texas, USA. Controlled conditions. September

Nick Upton / Parasite fly / Tachinid fly (Zophomyia temula), a nationally scarce species, feeding on Common hogweed (Heracleum sphondylium) on grassland meadow cleared of scrub to improve the habitat for bees and...

Rod Williams / Tachinid Fly (Thelaira nigrina) Hutchinson's Bank, New Addington, London May

Rod Williams / Tachinid fly (Tachina fera) Feeding on ragwort Hutchinson's Bank, New Addington, London September

Rod Williams / Tachinid Fly (Linnaemya picta) Brockley Cemetery, Lewisham, London, UK. August

Rod Williams / Tachinid fly (Nowickia ferox) grooming on wild marjoram, Hutchinson's Bank, New Addington, London August

Rod Williams / Parasitic Fly (Phania funesta) Tachinidae On field bindweed Brockley Cemetery, Lewisham, London, UK. August

Rod Williams / Parasitic fly (Eriothrix rufomaculata) on Tansy (Tanacetum) Brockley, Lewisham, London, UK. July.

Andy Sands / Tachnid fly (Prosena siberita) Berkshire, England, UK, August

Andy Sands / Tachnid fly (Phasia hemiptera) male feeding on flower of wild parsnip (pastinaca sativa), Oxfordshire, England, UK, August

Andy Sands / Tachnid fly (Phasia hemiptera) male feeding on flower of wild parsnip (Pastinaca sativa), Oxfordshire, England, UK, August

Andy Sands / Parasitic fly (Cacoxenus indigator) laying eggs into nest of Red mason bee (Osmia bicornis) in garden bee hotel / insect box . Hertfordshire, England, UK, May

Andy Sands / Parasitic fly (Cacoxenus indigator) laying eggs into nest of Red mason bee (Osmia bicornis) in garden bee hotel / insect box Hertfordshire, England, UK, May

Andy Sands / Tachnid fly (Prosena siberita), Berkshire, England, UK, August

Rod Williams / Tachinid fly (Thelaira nigripes) Brockley Cemetery, Lewisham, London, UK August

Stephen Dalton / Fly (Alophora hemiptera) Sussex, UK

Nick Upton / Parasite fly / Tachinid fly (Tachina fera) a parasite of noctuid moths, feeding on Ragwort flowers (Senecio jacobaea) in a woodland clearing, GWT Lower Woods reserve, Gloucestershire, UK, September.

Nick Upton / Parasite fly / Tachinid fly (Gymnocheta viridis), a parasite of lepidopteran caterpillars, sunning on an ivy leaf on a woodland edge, Wiltshire, UK, April.

Rod Williams / Parasitic fly (Eriothrix rufomaculata) on Tansy flower, Brockley, Lewisham, London, England, August.

Rod Williams / Parasitic fly (Eriothrix rufomaculata) on tansy flower, Brockley, Lewisham, London, England, August.

Rod Williams / Female Tachinid fly (Cistogaster globosa) on Tansy flower, Brockley, Lewisham, London, England, August.

Albert Lleal / House Fly (Musca domestica) covered with Mites (Macrocheles muscaedomesticae) which use the fly for transportation, Spain

Konrad Wothe / Tachnid fly (Tachinidae) Panguana Reserve, Huanuca province, Amazon basin, Peru.

Andy Sands / Tachnid fly (Tachina grossa) Surrey, England, UK. August.

Andy Sands / Tachnid fly (Tachina grossa) Surrey, England, UK. August.

Stephen Dalton / Parasitic fly (Dexia) Sussex, England, UK. July.

Rod Williams / Tachinid fly (Gymnosoma rotundatum) grooming, Brockley cemetery, Lewisham, London, UK, September.

Jussi Murtosaari / Flies (Brachycera) on leaf, Parikkala, Etela-Karjala / South Karelia, Etela-Suomi / South Finland, Finland. June

Rod Williams / Tachinid fly (Tachina fera) Brockley cemetery, Lewisham, London, England, UK. May

Pete Oxford / Cordyceps Fungus attacking fly (Cordyceps sp) Yasuni National Park, Amazon Rainforest, Ecuador, South America.

John Abbott / Parasitic Fly (Tachina sp.) on white background, Missoula County, Montana, USA.

Richard Du Toit / Burchell's Zebra (Equus burchellii) reacting to parasitic Bot Fly (Oestridae) trying to lay eggs on it, KwaZulu-Natal, South Africa

Stephen Dalton / Tachinid fly (Alophora hemiptera) parasitic species. Sussex, England, UK, August.

Stephen Dalton / Tachinid fly (Alophora) Sussex, England, UK, August.

Doug Wechsler / Gall (Polystepha pilulae) on Pin Oak (Quercus palustris) Morris Arboretum, Philadelphia, Pennsylvania, USA, August.

Michael Durham / Female Phorid / Shuttle fly (Pseudacteon obtusus) in flight above Red imported fire ants (Solenopsis invicta) searching for an ant to implant with an egg, Texas, USA, March.

Daniel Heuclin / Human botfly (Dermatobia hominis) larvae, on leaf, French Guiana.

Daniel Heuclin / Human botfly (Dermatobia hominis) larvae, on leaf, French Guiana.

Daniel Heuclin / Human botfly (Dermatobia hominis) larvae in dogs skin, showing breathing tube, French Guiana.

Daniel Heuclin / Human botfly (Dermatobia hominis) larvae in dogs skin, showing breathing tube, French Guiana.

Daniel Heuclin / Human botfly (Dermatobia hominis) larvae, on dog fur, French Guiana.

Jussi Murtosaari / Warble fly (Hypoderma tarandi) a parasitic fly whose larvae, once the eggs are ingested by reindeer, form swellings under the skin, Karigasniemi, Finland, July.

Chien Lee / Fungus (Ophiocordyceps dipterigena) parasitic mushrooms emerging from robber fly after it has consumed its interior, Tangkoko Nature Reserve, Indonesia

Rod Williams / Tachinid Fly (Phryxe sp) Lewisham, London, September

Andy Sands / Tachinid Fly (Prosena siberita), usually found in sandy areas where its larvae parasatise Euchlora beetles. Bedfordshire, England, UK, July.

Piotr Naskrecki / Vampire Bat (Desmodus rotundus) with parasitic Louse Flies (Trichobius parasiticus) behind its ear, Sipaliwini, Surinam

Nick Upton / Parasite fly / Tachinid fly (Prosena siberita) with distinctive long proboscis, resting on Woolly thistle leaf (Cirsium eriophorum), chalk grassland meadow, Wiltshire, UK, July.

James Christensen / Tarantula (Theraphosidae) carcass with the parasitic fly larvae that killed it, Mindo, western slope of Andes, Ecuador

Piotr Naskrecki / Wingless Bat Fly (Nycteribiidae) parasite on bat wing membrane, Papua New Guinea

Andy Sands / Hoverfly (Sicus ferrugineus). This fly deposits its eggs on various species of bumble bee that serve as hosts for the parasitic larvae. Hertfordshire, England, June.

David Maitland / Pigeon louse fly (Ornithomya avicularia) amongst the feathers of a Tawny Owl (Strix aluco). Feltwell, Norfolk, UK.

David Maitland / Pigeon louse fly (Pseudolynchia canariensis) amongst the feathers of a Tawny Owl (Strix aluco). Feltwell, Norfolk, UK.

Colin Varndell / Adult Common Rufous Parasitic Fly (Tachina fera) at rest on wayfaring tree leaf. Dorset, UK, August.

Colin Varndell / Ectoparasitic Ichneumon Wasp (Ichneumonidae) probing into pine bark with ovipositor. Dorset, UK, June.

Christian Ziegler / Bat Fly (Streblidae) ecto parasite on the wing of Great Fruit-eating Bat (Artibeus lituratus), Smithsonian Tropical Research Station, Barro Colorado Island, Panama

Kim Taylor / Parasitic Fly (Tachinidae) feeding on Hogweed (Heracleum sphondylium) flowers. Surrey, UK, June.

Tim Laman / Fig wasp (Waterstoniella masii) male has cut a passage through the fig wall and is seen emerging, females will use this passage to escape the fig and fly off to other fig trees carrying pollen. This...

Tim Laman / Fig wasp (Waterstoniella masii) male has cut a passage through the fig wall and is seen emerging, females will use this passage to escape the fig and fly off to other fig trees carrying pollen. This...

Stephen Dalton / Swallow louse fly (Stenepteryx hirudinis) parasitic on swallows, swifts and martins, note atrophied wings

Simon Colmer / Painted lady butterfly larva (Vanessa cardui)parasitised by Braconid wasp or Tabanid fly larva. (Remnants of caterpillar skin have fallen off leaf) Sussex, UK

Stephen Dalton / Ichneumon fly (Netelia testaceus) in flight. This image was sent into space on board Voyager spacecrafts 1&2 alongside other works of art.

Michael Durham / Phorid Fly (Pseudacteon obtusus) female flies above Red Imported Fire Ants (Solenopsis invicta) searching for an ant to implant an egg which eventually kills the ant, the fly is now used to help contr...

Stephen Dalton / Fly with parasitic lice attached to it, UK

PREMAPHOTOS / Alder fly female {Sialis lutaria} laying eggs on Rush stem, UK, Note - Two tiny parasitic wasps {Trichogramma semblidis} are ovipositing in the Alder fly eggs

PREMAPHOTOS / Alder fly female {Sialis lutaria} laying eggs on leaf, while a tiny parasitic wasp {Trichogramma semblidis} lays her eggs into a nearby batch of eggs, UK

Duncan Mcewan / Parasitic mites on fly (Diptera), Scotland, UK

Jabruson / Flower of {Hydnora abyssinica} parasite growing on Acacia roots and fly. Tsavo NP, Kenya

Mark Moffett / Army Ant (Eciton burchellii) carrying leaf, about to be landed on by tiny parasitic fly which will attempt to lay an egg on the submajor, the egg will then hatch into a larva which will consume the an...

PREMAPHOTOS / Cicada killer wasp (Sphecius speciosus) female dragging her Cicada prey (Tibicen similaris) back to her burrow while a (Miltogramma sp) female parasitic fly lays eggs on the Cicada, South Carolina, US...

Christian Ziegler / Mantled Howler Monkey (Alouatta palliata) infested with Bot Fly (Alouattamyia baeri) which only host on Howlers, warbles show air hole through which the larvae breathe, Barro Colorado Island, Panama

Piotr Naskrecki / Wingless Bat Fly (Nycteribiidae) on wing membrane of Fruit Bat, Guinea, West Africa

Piotr Naskrecki / Tsetse Fly (Glossina sp) the main vector for trypanosomes, the parasite that causes African sleeping sickness, Guinea, West Africa

Jose B. Ruiz / Parasitic fly {Salmacia divisa}

Kim Taylor / Parasitic fly {Prosena / Calirrhoe siberita} male showing haltere, Europe.