Marie Read / American avocets (Recurvirostra americana) two during aggressive (territorial) encounter, Bear River Migratory Bird Refuge, Utah, USA, May.

Nigel Cattlin / Marsh crane fly (Tipula oleracea) larva / leatherjacket attacking cereal plant, Wheat (Triticum aestivum), at soil level.

Nick Upton / Large marsh horsefly (Tabanus autumnalis) resting on a fence, Dorset, UK, July.

Nick Upton / Large marsh horsefly (Tabanus autumnalis) resting on a fence, Dorset, UK, July.

Konrad Wothe / Slow motion clip of a Bumblebee (Bombus) nectaring on a Marsh gladiolus (Gladiolus palustris), with a Bee fly (Bombyliidae) flying nearby, Bavaria, Germany, July.

Rod Williams / Snail-killing fly (Tetanocera Sp) Sutcliffe Park Nature Reserve, Eltham, London, England, UK. August.

David Kjaer / Marsh Snipefly (Rhagio tringarius) Ham Wall RSPB Reserve, Somerset Levels

Lorraine Bennery / Caterpillar larva of Elephant hawkmoth (Deilephila elpenor) on Grass of parnassus (Parnassia palustris) with hoverfly visiting flower, Regional Vosges Balloons Regional Park, France, August.

Nick Upton / Hoverfly (Volucella bombylans var. bombylans) a mimic of the Red-tailed bumblebee nectaring on Common spotted orchid (Dactylorhiza fuchsii) on grassland meadow cleared of scrub to improve the habitat...

Rod Williams / Snail-eating fly (Trypetoptera punctulatus) Brockley Cemetery, Lewisham, London, UK. May

Nick Upton / Marsh fly / Snail-killing fly (Dichetophora obliterata) standing on a Bramble leaf, Wiltshire hedgerow, UK, September.

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