"Mesh screens will be an essential part in the Integrated Pest Management and for pollination. On the one hand, the mesh will keep in the biological controllers and on the other hand, pests are kept out. But the care for bees and bumblebees also requires extra attention.
"Insect screens to protect bees and bumblebees? Yes it will allow them to remain safe from hornets. Hornets are more and more common in the Netherlands. This relative new insect feasts upon bees and bumblebees."
Although not many Dutch vegetable growers and flower growers have mesh in their greenhouse, the demand is increasing. Laurens Besemer of Ventiguard estimates the current number on only three percent, and he explains why he expects this percentage to increase.
Warm summers, more pests
The climate is changing worldwide. The weather is getting more extreme; heat, cold and precipitation. The number of pests increases because of the hot summers. Also in the Netherlands. "Last year, we had a warm summer, which caused more pests to appear at various growers. We received requests particularly from cucumber growers. During a series of warm days, insects multiply fast and suddenly you have to fight a plague. You are always one step behind. Mesh stops the influx of harmful insects and that offers the opportunity to keep the conditions in the greenhouse more in balance."
Choice for mesh
"The higher the yield per square meter, the higher the interest for insect screens. Plant growers as well as cannabis growers can benefit a lot." Growers in warmer climates, so closer to the equator, make (even) more use of insect mesh.
A calculation precedes the choice for insect mesh. "The cucumber growers who suffered a lot from pests this summer, know how much damage they had. They can calculate exactly what the insect screens will yield."
The insect screen also has impact on the cultivation. The air exchange is a little bit less, creating a different climate. This does not have to be a disadvantage for every grower. Sometimes, you can open the windows a bit further. If a grower is already using maximal ventilation, the mesh will result in more CO2 and higher air humidity."
IPM
Other reasons to assume that the demand for insect screens will increase in the Netherlands, are a result of the stricter regulation for crop protection agents and the increasing demand of the consumer for safely grown products. Laurens Besmer: "This all contributes to the fact that growers of both vegetables, and flowers and plants must start to grow as protected as possible in the future. A completely closed cultivation environment would be a solution, although you cannot compete economically with the free light and air exchange in a greenhouse."
For more information: 
Ventiguard
www.ventiguard.com
[email protected]
Laurens Besemer
[email protected]
+31 6 27 27 99 88