How to Establish Natural Enemies in Ornamental Crops

Biological control of arthropod pests has been applied successfully in greenhouse crops for decades. The list of worldwide commercially available natural enemies goes up to 230 species and the 25 most sold species are mainly the ones used in greenhouse crops. Considering this relatively high number of available species, one might think that most greenhouse pests can be effectively controlled through the use of natural enemies. However, quite the contrary is true. Although commercialized NEs can keep damage caused by the main greenhouse pests, such as whiteflies, spider mites, aphids and thrips below threshold levels in most vegetable crops, this is not the case for many ornamental crops. Moreover, new pests continue to emerge through the invasion of exotic species as a consequence of global trade and global warming, or as a result of reduced and/or more selective use of pesticides. Here I summarize both the currently most problematic and persistent, as well as the newly emerging pest species in greenhouse ornamental crops in The Netherlands, which is probably very similar to the situation Canada. Furthermore, I mention some new methods to support the establishment of natural enemies for pest control in ornamentals