Shore fly
on green algae. However, they can transmit plant diseases and can be a nuisance to greenhouse works by their sheer numbers. Frass deposited on leaves or [...] following stages: egg, three larval instars, a pupa and the adult fly. The eggs are laid singly and are bean-shaped. A first instar larva is translucent white [...] adult shore fly is black, about 4 to 5 mm long, and stout with short antennae and short legs. The head of the adult has a pair of conspicuous eyes. The wings