Shore fly
General Shore flies of the genus Scatella are a common greenhouse pest found throughout the United States, Canada and northern Mexico. In Europe and Asia, [...] life stages of shore fly feed primarily on microscopic algae, bacteria and other unicellular organisms, they do not cause any direct damage to plant production [...] quick fliers and can move throughout a greenhouse readily, they generally remain close to breeding sites. They breed in algae growing on soil, pots, benches