Bence Mate / Leaf cutter ant (Atta sp) female worker carrying leaf to nest, with a smaller 'minor' ant riding. The minor's job is to protect her sister from parasitic flies. Costa Rica, December. Highly Commended,...

Kim Taylor / Bachacs / Leafcutter ants {Atta cephalotes} carrying sections of Cocoa leaf bearing 'riders' thought to ward off parasitic flies which would otherwise lay their eggs on the pieces of leaf. Trinidad, W...

Michael & Patricia Fogden / Leafcutter Ant (Atta sp) group workers carrying leaf segments, note minim riding on leaf as protection against parasitic flies, rainforest, Costa Rica

Konrad Wothe / Leafcutter Ant (Attini sp) carrying leaf piece back to nest with smaller ant riding on leaf, small ant defends larger worker from parasitic flies, Honduras

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

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.

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