Belgian and Dutch tomato growers meet with Tuta absoluta

The micro moth, Tuta absoluta also known as “South American tomato pinworm, is a small leafminer belonging to the Gelechiidae family (Order: Lepidoptera).


Originating in South America, the caterpillar caused severe damages to the tomato industry in the Mediterranean region, digging bladder shaped ‘mine tunnels’ in the leaves of the plant. Infections in South America and the Mediterranean show that Tuta absoluta can really create quality issues and decrease the production.
As it was officially declared and first found in 2009 as a transient pest, it now seems to be one of the major pests the Belgian and Dutch sector is facing. Leaf damage leads to reduced photosynthesis and thus to lower production with potential harvest losses up to 50-100% in untreated crops.
The Tuta larva pierces into leaves and stems but can also inhabit the tomatoes themselves, making them unfit for consumption and sale.
 

Chemical control has been limited due to risk of immunity and its potential effect on beneficial insects already deployed in the greenhouse. However, a lot of the recent developed chemicals applied against T. absoluta are compatible and allowed to be integrated into an IPM strategy with the predatory mirid bug Macrolophus pygmaeus as a control agent. These developments lead to the fact that Tuta infestations are not a major issue anymore in some of the Mediterranean countries.

With this pest now occurring in the North-European region, Biobest has reacted promptly with the development of a sustainable, biologically based control strategy that is applicable in the Flemish tomato industry. This strategy, which has been implemented satisfactorily for the last years in Southern Europe and in Morocco, now is adapted to these new and more Northern countries. Our experience and advice are becoming of great importance to growers that now are under attack by this new pest to them.

 
Biobest’s strategy is mainly based on:
 

• Crop and technical measures: seal greenhouses with appropriate insect screen; remove affected plant parts, adequate hygiene in greenhouses.
• Monitoring with pheromone traps: Attract delta-traps and Tutasan water-traps
• Introducing beneficial organisms such as the Macrolophus-System (predatory mirid bug Macrolophus pygmaeus), by securing the population development with preventive introduction, increasing their introduction rate and feeding them with Nutrimac.
• Corrective use of selective pesticides that is compatible with beneficial organisms.
• Lately, Biobest encourages the introduction of Macrolophus already at the stage of propagation of young plants.
• More info on Tuta absoluta, its life cycle, damage and recommended control strategy, can be found on our website www.biobest.be or contact your advisor.