Cryptolaemus montrouzieri — often called the mealybug destroyer — is a predatory beetle used in biological pest management to control mealybugs and soft scale in indoor growing spaces and greenhouse crops. Adults and larvae are both active hunters that feed on mealybugs at all life stages, helping growers reduce pest pressure naturally without relying on chemical insecticides.

This species is part of the ladybird beetle family but is specialized for feeding on mealybugs, including citrus mealybug and long-tailed mealybug, making it a valuable ally in managing heavy infestations.

Here’s What They Look Like at Different Stages of Their Life:

Understanding the life stages helps growers recognize predator presence and activity in the crop:

• Egg: Eggs are small and oval, typically laid near mealybug colonies on leaf surfaces or plant stems.
• Larvae: They are the most voracious life stage. They are elongated and mimic mealybug larvae with their woolly filaments. Without these, they appear dark brown/black.
• Pupae: After feeding and growth, larvae pupate in sheltered areas on plants or greenhouse materials. They are inactive during this stage before becoming adults.
• Adult: Adults are small beetles about ~4 mm long with dark brown to black bodies. They are strong fliers and search widely across plants for prey. Adults feed on mealybugs and are highly mobile predators.

Note: Both adults and larvae feed directly on mealybugs, which helps control populations quickly when the beetles are released into the crop.

Why Growers Love It:

• Both larvae and adults feed on mealybugs, reducing populations effectively.
• Adults can move widely to locate prey.
• Works naturally alongside other biological controls.
• While mealybugs are preferred, related pests can also be eaten, like soft scale.
• Safe and residue-free for workers and crops.

Timing is critical to achieving success with predatory insects. They perform best when introduced before pests reach outbreak levels.

Preventive Use:

• Introduce Cryptolaemus montrouzieri as soon as a mealybug or soft scale insect is found. Early use helps prevent large infestations.

Curative Use:

• Deploy during times of high mealybug or soft scale infestations.
• Multiple releases may be required if pest pressure is high or crop is mature and dense.

Environmental Conditions:

• Most effective between 25–28 °C (68–82 °F). Activity slows at lower temperatures (< 16 °C).
• Above 33°C their searching behaviour comes to a standstill, while below 16°C they slow down until activity ceases at temperatures below 9°C.
• Adult ladybirds are good fliers and can disperse over a large area in search of prey.
• Prefer to work during the day. They love the sun.
• Avoid areas where recent broad‑spectrum insecticides were applied — such treatments may reduce performance of the predator.

Note: Monitoring is essential. Inspect leaves and stems, and any other plant crevices weekly to determine if additional releases are required. Remember the larvae perform mimicry, looking like the mealybug larvae.

Proper release techniques ensure the Cryptolaemus montrouzieri establish quickly and begin controlling pests effectively:

1. Distribute the product: (Bottle) Gently spin and place the larvae on rock wool slabs, in Dibox boxes, or directly on leaves near mealybug hotspots. Evening releases often improve establishment. (Box) Open in the growing space, and sprinkle them evenly through the area. They will begin flying around immediately after placement.
2. Recommended density: Introduce based on pest pressure. Cryptobug (adults): Typically 2–10 adults per m² per release in infested spots. Cryptobug-L (larvae): Often 5–40 larvae per m² per release, repeated at intervals until control is achieved.
3. Follow‑up releases: In curative situations or severe infestations, a second release after 7–14 days often improves establishment and control.
4. Avoid interference: Do not release immediately before or after broad‑spectrum insecticide applications. If treatments are needed, choose only those compatible with beneficial insects.