Limonica: an excellent method for keeping thrips in check

Lindy's Flowers Canada - Limonica against thrips

After struggling with biological crop protection in the past, Lindy's Flowers has seen great progress since partnering with Koppert Canada in 2014. Using the predatory mite Limonica and providing them with supplementary food has helped the company keep thrips infestations in check.

Lindy's Flowers was founded in 1980 by Jan and Wilma Lindeboom. The company is situated on a 1.2-hectare site in Dunnville, Ontario. Two thirds of the company is devoted to growing cut roses. The remaining 4,000 m² is used to grow snapdragons, or Antirrhinum. Scott Lindeboom, the couple's eldest son, is in charge of selling to wholesalers.
Ben Lindeboom is responsible for crop protection and greenhouse maintenance and oversees the cultivation process along with his brother. 'We'd used beneficials in the past, but we didn't have much success,' explains Ben. 'That’s why we started working with Koppert Canada in 2014. We started with Phytoseiulus persimilis to combat spider mites and also tested the effectiveness of Amblyseius swirski and Amblydromalus limonicus to combat thrips.'

An inevitable transition
Before making the switch to Koppert, Lindy's Flowers exclusively used chemicals to protect their crops. These chemicals did a reasonable job of controlling thrips, but the spider mite problem eventually got out of hand. 'A new chemical agent hit the market and it did a good job of keeping our crops free of spider mites. But six months later, after a new outbreak, the spider mites had built up resistance to the chemical and it had no effect. That's when we knew we had to switch to beneficials.'

Despite having some experience with beneficials, the transition wasn't easy for Lindy's Flowers. The first month was particularly difficult. 'The flowers still had a chemical residue on them, which made it hard for the beneficials,' recalls Ben.
During the transition period, it looked like the spider mite would prevail, but Phytoseiulus persimilis (Spidex) triumphed in the end. The predatory mite was applied successfully throughout the year, thereby keeping the damage to an acceptable minimum.

Quick population growth
The thrips, on the other hand, proved challenging in the long run. Lindy's Flowers tested the predatory mites Amblyseius swirski (Swirski-Mite) and Amblydromalus limonicus (Limonica) over a four-month period. The results were extremely promising. 'Limonica did significantly better than the Swirski-Mite,' says Ben. 'But we still needed some chemical corrections.'
Their consultant at Koppert Canada, Adam Hendriksen, recently advised them to use Artefeed. This would help the beneficials build a strong population, thereby increasing their effectiveness. 'That was a logical assumption. We already saw that Limonica developed better if it could live on whitefly as well as thrips.'

Excellent control
Lindy's Flowers began supplementing with Artefeed on a weekly basis. The effects were visible within weeks. 'In the part of the greenhouse where we supplemented the Limonica, we saw more population growth and we had more control over the thrips outbreaks.'
The company then started using Artefeed in all of its greenhouses once every two weeks. But this reduced the effectiveness of Limonica. 'We went back to weekly supplementation and our success rates went up as well. The Limonica are everywhere and the thrips are under control.'

Profit increases
'Ever since we transitioned to biological crop protection, the quality of the crop has thrived,' says Ben. 'Overall plant health and product quality has increased significantly. The rose stems are longer, production has increased, and the crops are much more stable.'
For Lindy's Flowers, the critical factor is containing thrips. 'Consumers in Canada and the United States don't really notice the damage caused by spider mites. That's not the case for thrips. This calls for a comprehensive approach to beneficials in order to be successful.'

Sales differences
Biological crop protection gives Lindy's Flowers a much-needed boost on the market. 'We can make our customers happy by providing consistently high quality. If we can ensure the quality of our flowers, we can maintain our market share, allowing us to supply a fresh, strong alternative to the imported product. As you can see, the beneficials make a real difference in terms of quality and sales.'
Lindy's Flowers is pleased with its collaboration with Koppert Canada. 'This is the first time we've been able to keep greenhouse pests in check. We owe much of that success to the products and knowledge of Koppert Canada.'