Limonica: biological alternative against thrips
Cucumeris and swirskii
Crop specialist Peter van den Berg is responsible for biological crop protection and other areas. Around the turn of the century, the organization began to develop this protection in its own show greenhouse. "Back then, the focus was mostly on thrips. Jan van Winden, the crop supervisor at Horticoop, which is our supplier of beneficials and other products, introduced us to Neoseiulus cucumeris (Thripex). Swirski-Mite entered the scene five years later." Whilst the beneficials did their job, chemical sprays were still necessary. "We had to learn the ropes," explains Peter. "Sometimes we were too late in using the beneficial, so the beneficials were trying to play catch-up from the start. We still had to get to grips with the system."
Results
In consultation with Jan van Winden and consultant Jenette Douma from Koppert, Peter began to use the new predatory mite Amblydromalus limonicus, or Limonica, in two sections on a trial basis. "After using the mite, we quickly began to notice an enormous number of mites in the crops - the scale was unprecedented. This was completely different from our experience with Swirski-Mite." Van den Berg went a step further in 2012. He set out to compare the effectiveness of the two types of predatory mite by using them both in an area measuring 800 m2 (two bays) in calendar week 11, in mid March. "We were running behind in 2012 as well, which had left a gap in the thrips control system. The result was identical: we noticed large numbers of Limonica everywhere, whereas we could only detect smaller numbers of Swirski-Mite."
Limonica
In 2013, Limonica was used on time, being released every four weeks starting from calendar week 6 (in February) and every two weeks after calendar week 26 (in June). Van den Berg chose to keep this working method in 2014, and Limonica once again was given the leading role. It was introduced into the crop using a Mini-Airbug. The dosage, calculated as a weekly average, is around 50 mites per square meter.
"Since then, I introduce Limonica on a weekly basis to parts of the greenhouse that I have doubts about and that I think could do with some more treatment in some cases. When the thrips population reaches its peak, which is usually around calendar week 33 in mid-August, I introduce extra Limonica predatory mites into the crop."
Peter van den Berg thinks that this beneficial can compete well with chemical products in terms of costs. "Chemical spraying always has to take place in the early mornings or in the evening. But that's now a thing of the past."
For more information:
Koppert Biological Systems
Email: [email protected]
www.koppert.com