Natural predators are widely used to tackle pests in greenhouse vegetable cultivation in northern Europe, but the cost of developing and producing ‘beneficial’ insects has limited their application on ornamental crops in Europe and greenhouse vegetables in the Mediterranean.
NOVELPHYTOS, a research project supported by the European intergovernmental initiative EUREKA, set out to tackle this challenge and develop novel mass production technologies for two groups of predatory mites: specialists, from the genus Phytoseiulus, which feed exclusively on spider mites; and ‘generalist mites’, which feed on many different insects. Koppert Biological Systems in the Netherlands worked on a system to rear generalist Phytoseiid mites; Israeli firm BioBee, focused on specialists.
INSECT MASS PRODUCTION
Traditionally, predatory mites are reared on a tritrophic system: meaning that it comprises plant, pest and predator. But growing plants, adding pests and then introducing the predatory mite is an expensive process: ‘You need heated greenhouses, light and soil,’ explains Elmer van Baal of Koppert, a world-leading company in rearing natural predators. Koppert’s strength lies in rearing predatory mites using factitious prey as an alternative food source. For Novelphytos, it used a mite commonly found on dried fruit and in beehives to rear Amblydromalus limonicus, a predator of thrips and whitefly on roses and gerbera.
It also succeeded in mass-producing the mite in containers filled with chaff.
‘The trick was to find an environment that feels natural to them. Then you can upscale and make it more economical and viable,’ says van Baal. By slowly refining the rearing environment, Koppert was able to have its insects ready for sale in early 2012, six years after the beginning of the project.
‘INSECTS THAT ARE PESTS' NATURAL PREDATORS ARE AS GOOD AS THE BEST CHEMICAL ALTERNATIVE.'
BioBee in northeast Israel has decades of experience in rearing Phytoseiulus persimilis, ‘the ultimate natural enemy of red spider mite worldwide. It’s as good as the best chemical alternative,’ according to R&D director Dr Shimon Steinberg (see TEDx video below). The star product of the company is already exported to 32 countries. Together with Koppert, BioBee managed to contract the process by extracting spider mite eggs from the plants and using them to rear P. persimilis in a controlled environment.
BioBee also developed a rearing system for Phytoseiulus longipes, another beneficial mite that attacks red spider mite but which is more successful than Phytoseiulus persimilis at controlling tomato spider mite, a devastating pest for plants such as tomato, potato, and red pepper in Africa and the Caribbean, but not yet widespread in Europe. ‘The fear that this pest mite might invade southern Europe from Africa was the trigger for this project,’ said Dr Steinberg. ‘So far, this forecast has not been realised, but we have developed a protocol to mass-produce the species and we would be ready commercialise it at a moment’s notice.’