Successful control of spider mite in hops with Natutec Drive

A growing number of Koppert’s biological solutions are being used to effectively fight pests and diseases in outdoor crops. Koppert’s patented release system, Natutec Drive, now makes it easier to distribute beneficial insects effectively over agricultural fields. In Germany, Natutec Drive has proven to be an efficient and labour-saving release system for biocontrol in hops.

Germany accounts for 69% of the total hops production in Europe, so protecting this crop is of great importance for this major beer producing country. It is little wonder that farmers began to look at alternative solutions when spider mite infestations presented growing problems in this valuable crop. The reduction in chemical pesticides on the market and crop resistance to pesticides have given farmers further reason to find biological solutions.

Using predatory mites to control spider mite

‘This outdoor crop is grown up trellises and reaches heights of up to 9 metres,’ Koppert field researcher Julia Eschweiler explains. ‘We needed to find a solution for the biggest problem hops farmers face in Germany – spider mite or Tetranychus urticae. The ideal solution also had to have a big reach.’

The predatory mites in Spidex (Phytoseiulus persimilis) and Spical (Neoseiulus californicus) are the answer for both the prevention and control of harmful spider mites, but distributing them evenly in the crop needs to be done accurately and efficiently over large tracts of land. ‘This is where Natutec Drive came in,’ Julia picks up the thread. ‘The release system that can be attached to most tractors only needed a few adjustments to make it ideal for distributing our beneficial insects in hops.’

Using air, Natutec Drive, gently propels the beneficial insects evenly over the crop through tubes. The device that can be attached to existing farm equipment, ensures uniformity of distribution and accuracy for different products and densities. Its unique patented design ensures the beneficial insects suffer no harm when the blower is used.

Manual vs. mechanical application of predatory mites

Initial trials with Natutec Drive were started in 2019 and showed promise. At this time, beneficial insects were still being applied manually. ‘In 2020 we decided to develop a prototype for outdoor applications,’ Julia continues. ‘We were blowing the insects up high, but this was eventually not the solution.’ A second prototype with a more precise dosage and airflow was finalized in 2022 and a new protocol was established. This time the predatory mites were distributed at the base of the plants and relied on the mites’ climbing ability. They proved to be good climbers. The new protocol also required setting out the predatory mites earlier in the season to give them a better chance to establish themselves in the crop.

‘Official trials with predatory mites conducted in collaboration with farmers in Germany have shown better efficacy than the chemical control,’ Julia states. ‘This gave rise to a great deal of interest from conventional farmers. We now have about ten hops farmers using Natutec Drive in Southern Germany.’ Julia shares that similar trials are underway in the UK and that Koppert is now looking at using Natutec Drive to release beneficial insects in potato fields and in orchards.

During the course of the project, Koppert Germany worked closely with Dr Florian Weihrauch at the Bavarian State Research Centre for Agriculture (LfL) where he is Head of the Working Group ‘Ecological issues of hop cultivation’. ‘The research centre annually conducts an official trial to prove the efficacy of our mites,’ Julia acknowledges. ‘We are grateful to Dr Weihbrauch and the research centre for this valuable collaboration and support.’