Predatory mites are tiny — teardrop-shaped, beige to white, and usually found on the underside of leaves or deep within growing tips. They may not be immediately visible, upon release, especially when they’re cold. Give them time to warm up and disperse, and they’ll soon begin working as intended.
❄️ Cold Temperatures Slow Them Down
Cold temperatures are the primary reason for sluggish mites on arrival. During the winter months, it’s common for predatory mites to appear inactive or slow-moving when they first arrive. This doesn’t mean they’re dead — it’s a natural response to cooler temperatures and seasonal conditions that temporarily reduce their activity levels. Once the products warm up and their environment stabilizes, the mites quickly resume their normal behavior.
Predatory mites are most active between 70–85°F (21–29°C), and when exposed to lower temperatures during shipping or storage, their metabolism slows considerably. Although Koppert Canada ships all beneficials in insulated cardboard boxes with cold packs to protect them during transit, even brief exposure to suboptimal temperatures can make them temporarily inactive. Allowing the products to reach room temperature gradually before inspecting them will help restore their mobility.
Why Do We Pack Ice in Our Beneficial Insects Even in the Winter? 🌬️
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You might wonder why Koppert Canada includes ice packs with beneficial insects, even when it’s already cold outside. The reason is simple: maintaining a stable, controlled temperature during transit is critical for keeping predatory mites and other beneficials healthy prior to arrival.
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Even in winter, outdoor temperatures can fluctuate widely during shipping. A brief warm-up while sitting on a loading dock or in transit can expose the insects to conditions that are too warm for their delicate metabolism. The ice packs allow for a temperature buffer, preventing overheating and ensuring that the mites remain dormant but viable until they reach your doorstep.
🌿 Plant Volatiles
Another factor is the reduced release of plant volatiles during a preventative application. These volatiles — natural chemical cues emitted by plants — help guide mites out of the sachets toward the crop canopy when there is a pest infestation. In the absence of strong plant scents, particularly when beneficials are introduced preventatively, mites may remain inside the sachet longer than usual. The sachets contain a food source that supports them while they wait for environmental cues to indicate the presence of prey.
📦 Understanding Batch and Product Differences
It’s also important to understand that sachet activity can vary between batches. Each sachet contains a guaranteed minimum number of predatory mites — for example:
- 250 in Swirski sachets
- 100 in Spical sachets
- 100 in Thripex Mini sachets
- 1000 in Thripex Plus sachets
Koppert always overpacks to ensure those minimums are met. However, Koppert does not guarantee the number of feeder mites inside a sachet, and the level of visible movement depends on both the number of predatory mites and the number of feeder mites present in a particular batch. Feeder mite populations fluctuate weekly, so some sachets will appear busier than others even though they contain the same number of predators.
🔍 How to Double Check Activity
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Upon receiving your shipment, let the sachets or bottles rest at room temperature for a few hours before opening them.
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Once warmed, you can inspect a few sachets to confirm activity — small, teardrop-shaped mites, beige to white in color, should be visible moving through the carrier material. Here are helpful videos:
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If you don’t observe movement after the sachets or bottles have warmed, record a 30-second video showing the contents and send it to us for review via email, WeTransfer, or Instagram. Please ensure that the video is stable and that there is no camera movement.
In short, slow movement in predatory mites during the winter, especially, is a normal, temporary condition. With proper handling and a brief warm-up period, they’ll soon resume their natural activity and begin working in your crop.
