Causal agent(s) and transmission
Leaf-miner flies belong to the order Diptera and include various species (European, South American and American, Liriomyza brionae, L. huidobrensi and L. trifolii, respectively). The larva is yellowish white to bright yellow and measures 0.5 to 3.5 mm. It lives in leaves before reaching the pupal stage; once becoming an adult, the insect flies away and can invade new environments.
As their name suggests, the larvae of these flies dig characteristic small sinuous galleries in the leaves of numerous plants, including the potato, without usually making any significant loss on yields (photos 1 and 2).
The life cycle of these flies lasts 1 to 1.5 months depending on the temperature and, in field conditions, there may be 3 to 4 generations per year.