Thursday, October 11, 2007
Leafminers are the larvae of beetles, flies, or moths. The adult female lays an egg beneath the epidermis of the leaf. After hatching the larva feeds on the leaf between the upper and lower epidermal layers, leaving clear trails or mines in its path. This photo is a leaf of Abutilon megapotamicum with a spectacular twisting mine. Supposedly the host plant and the shape of the mines are diagnostic for the many and varied leafminer species; this mine looks like American serpentine leafminer, Liriomyza trifolii but I can't confirm whether abutilon is a host species for that fly species, or whether a more likely suspect readily infests abutilon in southern California and creates a similar mine pattern.