Eristalis cryptarum (a hoverfly): a study of the phenology and extent of the Devon population, 1999-2000 (ENRR414)

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The Bog hoverfly Eristalis cryptarum may be confined to a small area of Dartmoor, Devon. A study in 1998 uncovered the presence of seven small sub-populations within the same area of Dartmoor and with work performed during 1999-2000 the range of the Bog hoverfly was increased to 12 sites. Populations at four known occupied sites were monitored throughout the summer of 1999 and were found to exist at extremely low densities. Oviposition for this species was observed and many behavioural and habitat records made. Suggestions were made as to the best management for the species and thoughts upon a trivoltine life history and possible localised dispersion were discussed.