cluster fly
noun1
Any of several species of Pollenia, especially Pollenia rudis, with the habit of congregating in dwellings over the winter.
- Cluster flies (Pollenia rudis (Fabricius) ) become a serious problem and a major pest in rural homes, churches, and other structures in the autumn when they enter buildings to hibernate, and again in the spring when they seek ways to escape to the outside.1960 July 1, David Pimentel, Benjamin Epstein, “The Cluster Fly, Pollenia rudis (Diptera: Calliphoridae)”, in Annals of the Entomological Society of America, volume 43, number 4, →DOI: