Signaling and monitoring Nesidiocoris with pheromone technique PheroNesi

Since the introduction of Nesidiocoris tenuis, also known as Nesi, in the Netherlands, growers in Northern Europe have been faced with a challenge. While this predatory bug is used in Southern Europe as a natural enemy against whitefly and Tuta absoluta, it is considered a potentially harmful pest insect here. In large numbers, Nesidiocoris can cause significant damage to tomato crops, resulting in necrotic rings and/or flower drop.

Damage in the crop caused by the predatory bug Nesidiocoris tenuis

To detect and monitor this threat, HortiPro introduced the PheroNesi pheromone last year. This pheromone, specifically developed for Nesidiocoris detection and monitoring, has delivered promising results for various growers who were dealing with a Nesi problem. Lennart Simonse provides an update.

Lennart is a Dutch grower who works with PheroNesi.

Positive results in practice

Results from conducted trials clearly show that PheroNesi makes a significant contribution to the effectiveness of Nesidiocoris monitoring. In trials where 20 yellow sticky traps with pheromone were compared with 20 yellow sticky traps without pheromone, a remarkable increase in captured Nesidiocoris was observed, up to 160%.

An additional advantage was the repellent effect on Macrolophus, where the presence of a PheroNesi dispenser in the yellow sticky trap resulted in significantly fewer captured Macrolophus (-37%). The values can be found in the graphs and tables below.

The positive reception of PheroNesi in France, where Nesidiocoris tenuis is an even bigger problem than in the Netherlands, indicates that the PheroNesi pheromone can be a promising solution for international growers dealing with this pest.

Optimal application of the PheroNesi pheromone

To ensure the maximum effectiveness of PheroNesi, some essential guidelines are important:

• In the summer, the pheromone lasts 6 weeks, while in the winter, the lifespan is 8 weeks. Replace the pheromone dispensers after this period.

• Use yellow sticky traps (with 14 mm holes) with dry glue. Nesi sticks better to this.

• Replace the yellow sticky traps if they are heavily soiled.

• Hang the dispensers in the greenhouse as soon as possible after receipt. If hanging is not immediately possible, store them in the refrigerator to prevent premature evaporation of pheromones.

• Hang the yellow sticky traps with the pheromone a maximum of 30 cm above the top of the crop. Attachment can be to yellow roller traps with a stapler or with magnetic hooks to the greenhouse legs if roller traps are missing.

Application of PheroNesi pheromone on a yellow HortiPro sticky trap

Recommendations for practical applications

For effective detection and monitoring of Nesidiocoris tenuis, the following guidelines are recommended:

• 1 to 2 yellow HortiPro sticky traps per 1,000 m².

• 10 to 20 yellow HortiPro sticky traps per hectare.

With high pest pressure, more intensive monitoring is required, with recommended numbers as follows:

• 10 to 25 yellow HortiPro sticky traps per 1,000m².

• 100 to 250 yellow HortiPro sticky traps per hectare.

To evaluate the effectiveness of the system, sticky traps without pheromone can be hung and compared with sticky traps with the PheroNesi pheromone. If more Nesidiocoris is caught on the yellow sticky traps with the PheroNesi pheromone, the functionality of the system is confirmed.

Capture of Nesidiocoris tenuis on a sticky trap with the PheroNesi pheromone.