With temperatures rising, thrips pressure in strawberry crops is increasing. The thrips population, especially in everbearers, can grow explosively. In addition to using predatory mites, growers can prevent damage to crops by also introducing the predatory bug Orius-System − explains Eline Braet, Crop Specialist Berries at Biobest Group.
“As everbearers are continuously in bloom, thrips can cause a great deal of damage,” she says. "The flowers affected grow into misshapen and bronze-coloured strawberries, which cannot be sold. It is important for growers to ensure a strong population of beneficial insects which can handle all stages of thrips."
Combination of beneficials
Eline explains that at the beginning of the cultivation season most growers introduce sachets containing predatory mites that feed on thrips larvae. Some growers rely on Amblyseius-System, while others introduce Swirskii-System. "We recommend introducing predatory mites weekly to maintain optimal levels of these effective predatory mites,” says Eline. “However, now that thrips pressure is increasing, we recommend also using Orius-System. This predatory bug eats thrips larvae as well as adults. For best results, we recommend growers to introduce Orius-System in small piles throughout the crop. The quantities needed depend on the pest pressure – which is best discussed with your Biobest Advisor."
Scouting and sticky traps
Of course, optimising pest control always begins with monitoring. "By shaking out several flower clusters, growers can gain good insight into the presence of thrips,’ says Eline. “Especially now that temperatures are rising, it is important to scout crops carefully. We also advise hanging up sticky traps or rolls."