Pest Identification

Identifying different life stages

Eggs are cylindrical and creamy/yellow or yellow, measuring about 0.35 mm in diameter.

Pupae are light brown and measure about 6 mm in length.

Adult moths are brown with silverfish-grey scales and black spots on the anterior wings, and have bead-like (filliform) antennae. The moth can measure up to 7 mm in length and have a wingspan of up to 10 mm.

Life Cycle

Eggs are typically laid on the underside of leaves, on young stems or sepals, with each female laying about 260 eggs in a lifetime. Larvae emerge after four to five days and immediately mine into fruits, leaves or stems, where they develop through four larval instars within 13-15 days. The larvae may then leave the mine to pupate in the soil or on the leaf surface, or alternatively pupation may occur within a leaf mine. Adults emerge after 9-11 days. The total generation time is between 30 and 35 days, and is dependent on environmental conditions, and populations can undergo many generations in a growing season. In Mediterranean regions, Tuta absoluta may undego 10-12 generations per year. In unfavourable conditions, this pest can overwinter at the egg, pupa or adult stage, however this is unlikely under glass, where an abundance of food is available and favourable conditions are maintained.

Insect stage that causes damage

Larvae cause feeding damage to fruit, leaves and stems, creating irregular mines and galleries, and black frass can be found surrounding feeding damage. Additionally, secondary infections can occur at sites of infestation. Feeding preference is typically shown to apical buds, flowers and new fruits.

When and where to identify

Tomato leafminer may be found throughout the growing cycle of a tomato crop. Adults are nocturnal, but may be found resting within the canopy during the day.

Geographical location

Tuta absoluta originated in South America, but has been introduced to Europe in recent years and is now considered a pest in a number of European countries, particularly in the Mediterranean region.

Damage

Timings

Damage inflicted by tomato leafminer can occur throughout the growing cycle of tomato crops, as this pest has a high reproductive capacity and is capable of attacking tomato plants at any stage of development.

The mines and galleries produced by feeding larvae can be found on fruit, leaves and stems, and may be surrounded by black, granular frass. These mines may or may not contain a feeding larva or pupa.

What and Where

Sex pheromone traps have been developed for the tomato leafminer and are effective as an early detection tool, and can also be used in mass trapping.

Susceptible plant species

The tomato leaf miner feeds on Solanaceous plant species, for example potato, aubergine and its main host; tomato. This pest is considered a serious threat to tomato production, in both protected and open field cultivation, particularly in the Mediterranean region.

Crops Affected by Tomato Leafminer

Tomato leafminer attacks Solanaceous crops, for example:

• Tomato
• Potato
• Aubergine

This pest is considered a serious threat to tomato production, in both protected and open field cultivation, particularly in the Mediterranean region.

Nemasys^®

Nemasys^® is based on the beneficial nematodes Steinernema feltiae and provides control of tomato leafminer (Tuta absoluta) in tomato production.

Nemasys^® contains nematodes in their vigorously infective juvenile stage. Once applied these nematodes seek out and control the larval and pupal stages of Tuta absoluta. It is also able to control sciarid fly larvae (Bradysia spp.) and the adult and pupae of the western flower thrip (Frankliniella occidentalis).

Once inside the insect they release symbiotic bacteria, quickly killing the pest. The nematodes then reproduce inside the insect and release a new generation of infective juveniles which disperse in search of further pests.

Nemasys^® is formulated in an unique non-residual gel formulation developed for foliar applications to ensure no residues on crops after application.