Leaf-Miner Fly
Agromyzidae
This small fly (less than 3 mm) emerged from the flower heads of
Desert Sunflower (Asteraceae: Geraea canescens) where the
immature larva had fed upon developing seeds. Observed near Parker, Arizona,
USA, March 2010.
Agromyzidae -- Leaf Miner Fly Family
Agromyzidae for the most part are leaf miners. Leaf miners are minute insects that tunnel through a leaf between the upper and lower cortex. Their activity is revealed by a transparent, serpentine tunnel that winds about within a leaf. Close inspection shows that the tunnel grows wider towards a terminus where the larva or pupa reside. Eventually a minute fly emerges. Normally, these insects are never abundant enough even to be noticed (except by entomologists). On occasion, particularily under unnatural conditions as in a greenhouse or over-sprayed garden they can become abundant and cause defoliation.
There are many species of Agromyzidae and most have a rather narrow range of host plants. Many are shiny black or black and yellow in color. Some species, like the one shown here, are specialists feeding instead within seeds or flower buds. The adult fly is shown below.
