The potato leafminer fly’s Indonesian name is "lalat pengorok daun" and its scientific name is Liriomyza huidobrensis.
This small fly is only 2–3mm long but is quite distinctive with a shiny black body and two yellow spots on their side and one on its back. They arrive in crops in swarms, usually in the early growth stages. They fly or run off quickly when disturbed.
Adult potato leafminer flies feed on potato leaves which results in spotting but does not cause any damage. In humid and moist conditions this feeding could make leaves more susceptible to disease infection.
Leafminer fly adults inject their eggs into potato leaves. Feeding and egg laying by adult flies appear as white specks on potato leaves. These white leaf specks are seen easily with the naked eye and are a good indication that a potato crop is infested with potato leafminer fly.
Eggs hatch into maggots which feed within the leaves, producing wiggly mines. Many maggots and their mines can be present on a single leaf.
Feeding by maggots causes damage because they kill leaves, preventing the plants from producing large tubers. Leafminer fly maggots do not have a pink area behind their head like potato tuber moth larvae. Also, there is usually only one mine per leaf when leaves are infested with potato tuber moth larvae.