At Bert’s Berry Farm we want strong plants, clean plants, and as few problems as possible in the season. Biological control is a key part of how we do that. We focus on prevention, we start early, and we stay on top of pest pressure before it has a chance to spread.

A couple of years ago we invested in our plant sauna, which helps us manage cyclamen mite, powdery mildew (Podosphaera aphanis), strawberry crown rot (Phytophthora Cactorum), grey mold (Botrytis Cinerea) with heat, not chemicals. It keeps our mother plants clean, it reduces stress in the season, and it fits the way we want to grow. Preferably less spraying, more control, better plants. Because of the plant sauna, it is easier for predators to start.

This is why we value the products from Chris Thompson and the BioForce team. One of the products we use, is Mite-E™ – Spider Mite Predator – 1000. We use this from the beginning of the season till the end. It supports strong plant health and gives us steady results across thousands of trays. Remember, often we’re gonna wait untill we see them to take action, but then it takes longer to get it back under control.

We’ve known Chris and his father for many years. They know their insects, they know their pests, and they know the real challenges growers deal with. When you talk with Chris, you always walk away with something practical you can apply right away.

You can learn more about BioForce and the work they do here.
https://www.bioforce.co.nz/

And now, here is this month’s guest blog from Chris Thompson.

As the strawberry season progresses, thrips season begins. Managing pests like thripsis a priority to ensure healthy yields and high-quality fruit. Thrips can cause significant damage to strawberries by feeding on flowers and fruit, leading to scarring and discoloration.

Fortunately, there are now 6 effective commercially available thrips predators and parasites on offer in New Zealand. Here’s a quick run down:

1. Mite A 

This predatory mite is highly effective in targeting thrips first stage larvae. Early release during peak thrips season will help reduce the population before they mature into adults that cause significant damage. Thrips larvae are the main culprits for scaring and projects in the UK on commercial strawberry farms have found they have inhibited damage with up to 11 thrips larvae per flower, in contrast without predators just 4 thrips per flower could result in damage.

 fun fact: cucumeris which we call Mite A that has been used globally for the past 40 years came from New Zealand!

2. Hyper Mite 

This predatory mite is highly effective in targeting thrips pupae in the soil and growbags. Typically applied twice in Spring to establish at the start of the thrips season. Recent studies in North America have determined Hyper mites alone are about 42% of the total thrips control. 

3. Orius 

Orius is a direct predator of thrips and can eat adults, although it often targets larvae first. These insects can fly and they hunt at night which makes them harder to spot. For best results, release Orius as soon as thrips appear. There is no benefit in releasing them before thrips are present.

4. Nemaplus 

These beneficial nematodes target soil-dwelling thrips pupae, reducing populations before they can emerge and damage the crop. These are a wettable powder which can be sprayed onto the ground or applied through drip irrigation systems. Also a good option to apply to plug plants after transplanting if fungus gnats are present.

5. Nemaflor F 

Nemaflor F contains the same nematode species used in Nemaplus, but the gel carrier makes mixing easier and leaves no residues after spraying. Growers often prefer Nemaflor F in Spring and early Summer when grow bag temperatures sit between 15 and 25C. It works on thrips, caterpillars, fungus gnats and ants. This option is suited to tunnel growing or bench systems.

6. Nemaflor C 

Nemaflor C contains the nematode Steinernema carpocapsae in a gel carrier, so mixing is easier and no residues remain after spraying. Growers tend to choose Nemaflor C in Summer when grow bag temperatures rise above 24C. It controls thrips, caterpillars and root eating grubs. This option is suited to tunnel growing or bench systems.

Integrated Pest Management (IPM) Strategy:

For optimal thrips control, combining biological agents with sound cultural practices—such as good spacing, proper irrigation, and regular pest monitoring—will provide the most effective results. Early intervention, coupled with consistent monitoring, is essential to keep thrips under control without relying on broad-spectrum pesticides. As thrips control relies heavily on beneficial mites it is important to keep other pests like the twospotted spider mite under control with compatible means. Mite E is an exclusive predator of spider mites that can be applied during the season to squash pest populations. 

Mass trapping with sticky traps can be helpful, though industry leaders in the UK, North America and Australia recommend pairing traps at a minimum with cucumeris (Bioforce Mite A). To get the best value out of traps ensure dust and spraying is kept to a minimum. 

Success with biological products in all crops starts in the nursery. Plant propagators often have the ability to use much harsher chemicals than growers as they are applied longer before fruit production. Unfortunately the residual compounds can linger many months inhibiting the establishment of predator mites and insects even though the fruit would pass an MRL test. 

If you’d like to learn more or need advice on implementing these strategies for your farm, feel free to reach out. Let’s work together to ensure a successful and pest-free strawberry season.

Bio Force Ltd
Chris Thompson
72 Sim Road
Karaka
Ph: (09) 294 8973
office@bioforce.net.nz
https://www.bioforce.co.nz/