Dagger fly, SEM

Empis sp. Coloured scanning electron micrograph (SEM). Common names for members of this family are dagger flies (previously dance flies)(referring to the sharp piercing mouthparts of some species). The proboscis is often long and in several genera powerful and piercing. If the mouthparts are strongly elongate they project forward or downward toward the fore legs ( seen here). Because of their predation they are important natural and biological control agents of various pest insect species and as a group with a vast species diversity they occupy a wide range of habitats. Some adult Empididae also visit flowers to obtain nectar. Males present a 'gift' of a dead insect before mating. Females do not mate with males who do not offer a gift. Magnification: x50 when printed 10 centimetres wide., by STEVE GSCHMEISSNER/SCIENCE PHOTO LIBRARY