Summary[edit] Description: English: The fly larva was collected at Scherenbrugg, Switzerland in 1994. This was a feeding assay to determine whether it would consume larvae of Phratora vitellinae, a leaf beetle that feeds on willows and produces a host derived defensive secretion. Date: 6 November 2007. Source: Own work. Author: NCalBeetleGuy.
Summary[edit] Description: English: Parasyrphus females lay their eggs next to or among eggs of the leaf beetle species that their larvae prey upon. This picture was taken in the field in eastern Finland as part of an ecological study (Rank et al. 1998, Ecology 79:618-631). Date: 6 November 2007. Source: Own work. Author: NCalBeetleGuy.