"The pressure of this pest is increasing. Because chemical agents are barely effective, growers are having difficulty in suppressing Tuta absoluta", adviser Jurgen Bouveroux states. The biggest problem are the caterpillars, that cause damage by making holes in leaves, stalks and fruits. The moths themselves are about 7 millimeters long and mainly fly at night.
Moths in the picture
Bouveroux advises a combination of measures to prevent damage. "In the first place, we advise growers to significantly increase the number of pheromone traps per hectare. The Delta trap with the pheromone for Tuta absoluta makes it possible to better monitor and suppress the infestation. The use of black traps - preferably against a white background - we can recommend additionally, because the moths like to sit on a dark surface."
Macrolophus-System
Furthermore, the adviser recommends to keep the biology in the greenhouse up to par, in particular the predatory bug Macrolophus pygmaeus. This important predator eats larvae and eggs from the greenhouse whitefly and the tobacco whitefly, as well as those from Tuta absoluta. Because of its voracity, M. pygmaeus has proved effective in combating this pest. "Growers can keep the population of this predatory bug at full strength by using alternative food sources such as Nutrimac and Artemac."
New BT resource
In order to tackle the larvae of Tuta absoluta, growers can use the new organic pesticide Delfin WG, which Biobest has included in its assortment since mid-February 2018. This agent is effective against various caterpillars and contains traces and crystals of Bacillus thuringiensis from the subspecies kurstaki. "Like other BT compounds, growers have to spray it on the leaves. When the larvae eat the leaves, it is converted into toxins in their digestive tract. It is most effective with young caterpillars. So it's important to monitor the pest well and to start the control measures in time." Of course growers can contact their Biobest adviser for tailor-made advice.
For more information:
Biobest Group NV
www.biobestgroup.com
Lise Verachtert
[email protected]
