Common Name: Tomato Leafminer
Latin Name: Tuta absoluta
Main Host(s): Tomato
Tuta absoluta has received a lot of attention in recent years. Also known as the Tomato Leafminer, the pest is originally from South America, where it remains a problem. It has spread to Mediterranean and Middle Eastern countries, moving up into greenhouse areas of Hungary and Southern Germany. Recently, USDA officials have become concerned that the pest may spread to Florida.
The pest is best known for attacking tomato but has also been found feeding on potato, eggplant and green bean. Tuta is an open field pest in warm climates but especially in greenhouses it can proliferate quickly and produce 10-12 generations each year.
A Tuta female can lay several hundred eggs, singly on plant terminals. The eggs hatch in 4-6 days, and with 4 larval stages and a short pupal duration, a new generation appears in 30-35 days under optimal conditions. Larvae will appear many times at the plant surface for molting into the next stage. They can move to other plants, making new galleries. When populations increase tomato stems and green fruits are attacked. Tuta can overwinter as egg, pupa or adult.
Impact & Damage
The larvae feed voraciously on tomato plants, with damage resulting from the larvae boring into leaves, stems and fruits. Within a few months, various life stages overlap and a multitude of control options need to be employed to keep the pest under control to prevent yield losses which can amount to total crop loss.
An effective T. absoluta control program treats the pest as soon as it appears. Growers can use pheromone traps to determine when to begin, and should begin applications when the adult moth population is low and egg laying has just started. Superficially and at low populations leaf damage from Tuta larvae looks similar to the damage of Liriomyza Leafminer Fly larva. Insecticides against Liriomyza may not work against Tuta. Effective IPM programs using beneficial insects and biorational products such as DiPel® and XenTari® have been developed especially for greenhouses (Spain, Italy, Morocco).