One of the main challenges for tomato growers in recent years has been the difficulty in controlling Tuta Absoluta.
A tiny tomato leafmine (Lepidoptera : Gelechiidae), Tuta Absoluta is causing devastating effects for growers in the mediterrenean region.
The pest originated from South America where it has been around since the 60’s and was first found in Spain in 2006 where it probably came from infested plants or fruits. It rapidly spread all over the Mediterrenan region where it found a perfect environment to reproduce. Tuta Absoluta is also found on potato and Aubergines. It affects both outdoor and greenhouse tomatoes.
This gelechiidae moth has shown an incredible capacity to adapt to environmental and climate change as well as enormous biotic capacity.
It is about 5-7 mm long with a wingspan of almost 1cm. An adult female can lay up to 260 eggs during its lifetime and hatch after 4-5 days. It can overwinter as eggs, pupae in the ground or in the plant.
In a tomato plant it appreciates everything but the roots and it can
infect it at any stages of its development, from seedling to the point where the tomato is fully mature, it infects most parts of the plant (leaves, stems ,flower fruit).
Tuta Absoluta behaves like leaf mine, the larvae mine the leaves or tomato fruit, producing galleries and burrow into the fruit. The damage in the worse case can make 100% of harvest unusable for commercialization.
The insects lay their eggs under the leaves or stem. Once the egg hatches the larvae penetrates into the leaves and tomato fruit creating long galleries.
The moth reproduces very frequently in a year (10 to 12 times) and lives for around 25 – 40 days in the summer period without diapause if the climate is favourable and there is a continuation in the plant cycle (9-10 months cycles in greenhouses).
Tuta Absoluta has been found very difficult to control, it has shown to be resistant to pesticides and has few natural enemies. The use of biological factors are not fully developed and research assistance is experimenting with various integrated pesticide systems in order to formulate the best practices and information and guidance to tomato growers.
Integrated pest management are being tested and include various techniques from massive trapping before planting, clearing the soil of residues 6 months resting before replanting, crop rotation with non solacenee species, release of natural enemies, and application of special grids in case of greenhouses .
Other systems include trapping of the pest with pheromone baited traps in water. Agraz is also experimenting with biological tests to fight Tuta Absoluta. One of these was to release a natural predator named Nesidiocoris tenuis. The result of this test has been outstanding. We have managed to reduce the input of chemicals treatment with significant economic savings.