In 2020, 95 percent of the greenhouse crops were biologically controlled with parasitic wasps or predatory mites. In 2016, this was 92 percent, and in 2012 78 percent. For each of the crops studied, biological pest control should be applied to at least 75 percent of the cultivated area by 2020. These are preliminary results from a CBS survey on biological crop protection conducted among 1,315 greenhouse horticulture companies.
In 2020, biological pest control was used on the entire cultivated area of cucumbers, peppers, and tomatoes in greenhouses to combat pests and spider mites. For these three food crops, the use of biological pest control was already high in 2012. For example, 96 percent of tomato acreage and almost 90 percent of cucumber and sweet pepper acreage were treated with biological pest control in 2012.
The use of biological pest control on strawberries grown under glass has increased significantly: from 58 percent in 2016 to 98 percent in 2020. Ornamental plants such as roses, gerberas, and chrysanthemums will also have a biological control share of more than 90 percent in 2020. Only pot plants - for flowering or for foliage - lag behind with 75 percent and 81 percent, respectively.
From top to bottom: Total of 9 crops, tomatoes, peppers, cucumbers, roses, strawberries (under glass), gerberas, chrysanthemum, pot plants (foliage), pot plants (flowering)
Increasing numbers of biological control agents used
Four main groups of biological control agents are used to combat pests in greenhouse horticulture. Around 52 billion predatory mites and parasitic wasps were deployed in 2020, almost five times as many as in 2016. The number of parasitic wasps and gall midges deployed adds up to 2.4 billion, more than twice as much as in 2016. The numbers of predatory bugs, lacewings, hoverflies, and predatory beetles are considerably lower at 0.2 billion, but more than twice as many as in 2016. The fourth group of biological pest control agents is nematodes: these are used in high numbers in greenhouse horticulture, but only numbers for 2020 are available (5,202 billion).
Increase in the cultivated area with predatory mites and predatory thrips
The use of predatory mites and predatory thrips on all nine crops studied increased slightly, from 66 percent of the cultivated area in 2016 to 69 percent in 2020. The use of these biological pest control agents increased, especially in the cultivation of strawberries under glass (98 percent of the area, against 54 percent in 2016) and in gerberas (98 percent against 68 percent). In tomato cultivation, predatory mites play a less important role. There, parasitic wasps are more important as biological control agents.
From top to bottom: total 9 crops, roses, cucumbers, peppers, strawberries (under glass), gerberas, chrysanthemum, pot plants (foliage), pot plants (flowering), tomatoes
Strongest increase in use of parasitic wasps in rose production
In 2020 parasitic wasps and gall midges were used on 74 percent of the total area of the nine crops in greenhouse horticulture. In 2016, this was still 67 percent. These biological control agents are widely used in the cultivation of peppers (98 percent of the area), tomatoes (95 percent), and gerberas (94 percent). The biggest increase in use was in rose cultivation: from 52 percent of the area in 2016 to 82 percent in 2020. In both types of pot plants (flowering and foliage), the use is less than 40 percent of the cultivated area.
More predatory bugs, flies, and beetles used as pesticides
The use of predatory bugs, lacewings, hoverflies, and predatory beetles in greenhouse horticulture increased from 54 percent of the cultivated area in 2016 to 61 percent in 2020. In pepper cultivation, this group of insects is used for pest control on 98 percent of the area, followed by tomato cultivation with 93 percent. The use of these biological pest control agents increased significantly in the greenhouse cultivation of roses, from 25 percent in 2016 to 56 percent in 2020. The other crops, excluding chrysanthemums, also saw an increase. In cucumber cultivation, this group of biological control agents is little used (8 percent of the total area), as it is predatory mites that are mainly used.