Category: News
Date published: April 25, 2016

Predatory mites against thrips and whitefly - a question of customization

Koppert has a number of predatory mites which can be used to combat thrips and whitefly. Each has its unique strengths. However, they must meet one requirement, which is to contribute to a biological system that ensures the highest possible level of harvest security. Read on to find out everything you wanted to know about these predatory mites.

Bring together Tim Bossinga, Ben Driessen, and Yvonne van Houten to talk about predatory mites and the conversation automatically revolves around a major chapter in Koppert’s history. Tim Bossinga is Product Manager Biologicals, Ben Driessen is team leader and consultant for vegetable crops in the Netherlands, and Yvonne van Houten is Senior Researcher of entomology. Thanks to their professional backgrounds, each possesses a great deal of knowledge about the market for predatory mites.

Cucumeris - still going strong
When it comes to predatory mites that are used to combat thrips and whitefly, Neoseiulus cucumeris, which also goes by its brand name ‘Thripex,’ is an old hand in the market. ‘It may be old, but it’s still
going strong,’ says Yvonne van Houten. ‘Cucumeris is a generalist: while it preys on thrips, it also eats
whitefly and some spider mites. It is active from 12°C and is a trump card in the fight against pests even in temperate regions. Given this quality, it’s no wonder that it is widely used as a beneficial in Thripex, Swirski-Mite, Limonica Predatory mites against thrips and whitefly - a question of customization different vegetable crops such as cucumbers and strawberries.’

Swirskii - bullseye from the beginning
Koppert brought Amblyseius swirskii onto the market more than ten years ago. The beneficial was an instant success. At the time, it was being developed for use in Mediterranean countries. This was due to
the fact that, while swirskii is active in temperatures from 15°C to 16°C on up, it continues to prey on and
eat pests at extremely high temperatures until well into the thirties. Tim Bossinga explains, ‘This characteristic means swirskii is also suitable for use in glass greenhouses in temperate regions. In the
summer months, the temperature within the greenhouse is liable to shoot up.’
Amblyseius swirskii, also known by its brand name ‘Swirski-Mite,’ is a generalist: while it combats thrips and whitefly, it also has a side effect on spider mites and other mite species. It is this versatile nature which has driven its success.

Limonicus - extremely aggressive
Although Amblydromalus limonicus has only been on the market a few years, it has a fairly long history. Koppert had known for a long time that this mite was an effective beneficial in the fight against thrips and whitefly. However, it proved impossible to produce. It was only after a considerable amount of research that Koppert was able to reproduce limonicus in a patented breeding system. Koppert brought it onto the market in 2012. Limonicus, known by its brand name ‘Limonica,’ differs from Amblyseius swirskii in the way that it is active even at lower temperatures (from 11°C). This attribute means it is suitable for use in colder regions and on early crops. It lays a lot of eggs and is extremely aggressive. Limonicus preys on
both the eggs and all larval stages of whitefly, and also eats larger thrips larvae. This behaviour allows it to build up a stable and strong population whilst keeping whitefly under control. It is less effective at very high temperatures. Swirskii is your best option in this case.

Harvest security as a priority
Koppert is constantly looking for new beneficials. ‘We want to offer growers a system that enhances harvest security. This is why we continue to work on developing even better products,’ says Tim Bossinga. ‘When it comes to discussing which beneficials we bring to market, the predominant criteria
is the contribution we can make to harvest security. Every new predatory mite must add something to the range of predatory mites that Koppert produces.’

The most progress
Biological crop protection is complex - success doesn’t happen automatically. It is inevitable that one of the ingredients of this success is to have a carefully planned out strategy for each business. In this respect, the grower and his/her consultant must look at factors such as the level of infestation, the crop, or even the cultivar, as well as the temperature spectrum that beneficials can tolerate, the speed at which they build up their populations, and to what extent they are a specialist or generalist species. It’s always a question of customization.

The best strategies come from an assessment of these factors, which requires specialist knowledge and advice. This explains why Koppert works with crop teams and crop specialists. Ben Driessen clarifies, ‘The crop teams and specialists, our R&D people, and our distributors are specifically looking to cooperate with growers. This cooperation must happen in practice, which is why we maintain such close contact. This approach means everyone works towards making the most progress.’

To feed or not to feed
Cucumber growers sometimes provide predatory mites supplementary food in the form of pollen. This is not without its problems. The use of pollen increases egg laying and decreases the mortality rate, which leads to explosive growth in the thrips population. Ben Driessen: ‘If the predatory mites introduced to the crop choose to eat pollen as part of their diet or even as the sole source of nutrition, then the battle against thrips is lost. There is still a lot to be learnt about this approach. Providing a solution is without a doubt a question of customization.’

An overview

Thripex (Neoseiulus cucumeris)
• Combats thrips and also eats whitefly, spider mite, and other mite species.
• Can be used in temperatures of 12°C and above.
• Suitable for colder regions and early greenhouse crops.

Swirski-Mite (Amblyseius swirskii)
• Combats thrips and whitefly, and also eats spider mite and other mite species.
• Can be used in temperatures of 16°C and above.
• Suitable for warmer regions and greenhouse crops in temperate climates.

Limonica (Amblydromalus limonicus)
• Combats thrips and whitefly, and also eats spider mite and other species.
• Also eats second-stage thrips larvae.
• Rapid population growth if enough prey is available.
• Can be used in temperatures of 11°C and above.
• Suitable for colder regions and greenhouse crops in temperate climates.