Cluster-flies
Guides
Pollenia
cluster flies, attic flies
Pollenia is a genus of blow flies commonly known as cluster flies or attic flies. Unlike typical carrion-feeding blow flies, these insects are parasitoids or predators of earthworms and other invertebrates. Adults are medium-sized flies that frequently enter buildings in autumn to overwinter in sheltered locations, becoming active on warm winter days and emerging in spring. The genus contains approximately six species in North America, with Pollenia rudis and P. pediculata being most common. Species identification requires microscopic examination of setae patterns.
Polleniidae
cluster flies
Polleniidae is a family of calyptrate flies in the order Diptera, commonly known as "cluster flies." The family was elevated from subfamily rank within Calliphoridae to full family status in 2019 based on phylogenetic evidence. It comprises approximately 150 species in eight genera, with Pollenia being the most diverse and widespread genus containing about 95 species. Members are primarily soil-dwelling and develop as endoparasitoids of earthworms.