Apr 14, 2023

Biobest recommends introducing raspberry predatory mite

Biobest is reminding growers that it is time to introduce preventative predatory mites in raspberries.

As raspberry plants come out of dormancy, pests generally appear soon. For crops grown in tunnels, now is the time to be prepared, Gaby van Kemenade, a Biobest advisor, said in a news release. To stay a step ahead, she recommends growers make preventative introductions of Californicus-Breeding-System or Andersoni-Breeding-System.

As the product names suggest, Biobest offers californicus or andersoni predatory mites in breeding sachets. These contain food enabling the predatory mites to reproduce and be released on to the crop over a six-week period.

“The strategy depends on the situation in the crop,” van Kemenade said in the release. “While A. californicus mites are more specialized in controlling spider mite, A. andersoni mites have a more generalist approach – also targeting thrips and other pest mites. Andersoni is also very much at home in woody crops and is more resistant to cooler temperatures.”

The sachets possess an integral hook and are easy to hang in the crop, according to the release. Biobest recommends hanging one sachet every 6.5 feet as standard. The predatory mites are also available as sprinkling material – Californicus-System and Andersoni-System.

Later in the season, as temperatures begin to rise, spider mite hotspots can develop, necessitating the use of more beneficials,” van Kemenade said in the release. “We recommend extending control with Phytoseiulus-System. Effective at 59 degrees Fahrenheit and above, the voracious Phytoseiulus persimilis, predatory mites tackle spider mite hot spots.

“We recommend an introduction rate of 15 to 20 mites per metre. Phytoseiulus has a striking red colour and is a real spider mite specialist – it cannot survive without the pest,” van Kemenade said in the release.

Raspberry growers can also improve pollination rates.

“In April, raspberries in tunnels come into flower, but the days can still be cold and dark, causing pollination issues,” van Kemenade said in the release. “To optimize yields, we recommend deploying bumblebees. Compared to other pollinators, they continue to fly and pollinate better under these conditions.

“Our Multi-Hives contain three bumblebee colonies, packed in a weatherproof outer box. This ‘jacket’ is also available for individual nests under the name Bee-Coat. This protection ensures bumblebees continue to carry out their work in the best possible way,” van Kemenade said in the release.

Biobest provides growers a wide range of biological control and pollination products.

PHOTO ABOVE: Introducing preventative predatory mites can help prevent pest infestations of raspberries, according to Biobest.