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Cryptolaemus montrouzieri

Cryptolaemus montrouzieri

$25.00 USD
$25.00 USD
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Size
Life Stage

Cryptolaemus montrouzieri, commonly known as the "Mealybug Destroyer," is a specialized ladybird beetle that feeds almost exclusively on mealybugs. Unlike generalist predators that eat anything, "Crypts" are targeted hunters designed to crash heavy mealybug populations. They are famous for their unique larvae, which use aggressive mimicry to look exactly like their prey. We offer both life stages: the flight-capable Adults for general coverage and the voracious Larvae for targeted hotspot cleaning.

  • Scientific Name: Cryptolaemus montrouzieri

  • Best For: Eradicating Mealybugs (Citrus, Long-tailed, and more) and Soft Scale.

  • Safe For: Plants, humans, and pets.

  • Key Feature: Their larvae look like giant mealybugs ("Wolf in sheep's clothing") to trick ants and get close to prey.

Where your larvae go

The mealybugs on your leaves are not the colony. They are the ones that left it, out feeding where you can see them. The colony itself sits somewhere sheltered — a leaf axil, the underside of a crown, the crevice where a stem meets the pot — and that is where the eggs and the wax are. That is where your larvae will head.

So the honest answer to "where are my larvae" is usually "wherever the main colony is." If you do not know where that is yet, finding it is the most useful hour you can spend on this plant.

Two things make them hard to spot even when you are standing over them. They look almost exactly like the pest they are eating — the poke test in the FAQs on this page is how you separate the two. And they are working the part of the plant you do not routinely look at.

Wipe off the ones you can see — once you have checked they are mealybugs and not your own larvae. The visible mealybugs are the minority, removing them by hand costs you nothing, and your larvae are not working that population anyway.

A larva that did not make it is obvious — it looks like a dead insect, not like nothing. Seeing nothing at all is the normal case.

Reading the first couple of weeks

Judge it on mealybug pressure, not on predator sightings. Around the two-week mark you will be looking at one of three pictures, and they mean different things.

  • Pressure thinning. You have enough larvae for this colony. Leave them to finish.

  • Pressure holding steady. The larvae are keeping up but not gaining. Release again — you are short, not wrong.

  • Pressure quiet for a while, then climbing again. The larvae did the work and have since pupated. A larva has one feeding window: it eats through four increasingly large instars and then it stops. Release again.

Controlling an established mealybug colony usually takes weeks and more than one release. That is the shape of the method, not a sign it has gone wrong.

Field Notes

Cryptolaemus montrouzieri

The beneficial

Species
Cryptolaemus montrouzieri
Common name
Mealybug destroyer
Type
Predatory ladybird beetle — a specialist that feeds almost exclusively on mealybugs
Size
Adults are small black lady beetles with orange heads and tails. Larvae are white and waxy and look nearly identical to mealybugs, but larger — up to about 1/2 inch — and much faster
How it works
Hunts on foliage. The larvae are covered in white wax and look like oversized mealybugs, which fools ants and lets them feed inside a defended colony

What it eats

Hunts
All species of mealybugs — citrus, long-tailed, obscure, root mealybugs
Best against
Mealybugs in numbers, clearly visible. On a plant with three insects on it, they leave
Also eats
Soft scale insects, specifically the crawler stage
Eats opportunistically
Aphids, if starving. They require mealybugs to reproduce
Won't touch
Armoured scale — the hard little limpets that will not squash. That job is Rhyzobius lophanthae instead

What arrives

Format
Tubes, bottles or a box, depending on the stage. Adults ship loose, with no carrier at all. Larvae ship in buckwheat hulls — the white waxy things in there are the predators and not an infestation, so resist the urge to squash them
Role
Two stages, sold separately. Larvae for a specific heavily infested plant: they cannot fly, so they stay on the plant you place them on until the colony is gone. Adults for coverage: they fly to locate scattered mealybug pockets and lay eggs for a future generation
Ships as
Adults or larvae

Where it works

Optimal temp
Active between 64°F and 90°F. They love heat and sun, and slow right down in a cool space — a warm greenhouse and houseplant predator
Humidity
Warm and humid. They are tropical in origin and perform best there
Light
Adults are attracted to light and are most active on sunny days, unlike the predators that hide in the dark
Establishes
Adults are programmed to fly off to find food and will disperse if the mealybug population is too low or the room is too cold. Where there is a colony they lay eggs and a generation follows. Larvae cannot fly, so they stay

Running it

Deploy
The day it arrives — neither stage holds well in a container. Mist the plants lightly first; the beetles are often thirsty after shipping
Placement
Directly onto the infested plants, close to the mealybug colony. Transfer larvae into the clusters themselves with a small paintbrush or the tip of a leaf, and do not squeeze them. For adults, open the container near the infestation
Release timing
Evening or early morning, onto foliage that has been watered
Refrigerate
No. If you must hold them, 55–60°F for no more than 18 hours
Compatible with
Soil predators for root mealybugs — Stratiolaelaps scimitus or root aphid nematodes — since Cryptolaemus generally hunt on foliage
Keep separate from
Ants. They defend mealybugs for the honeydew and will kill your predators, and the mimicry only gets a larva so far. Bait or barrier them 2–3 days before release
Chemical interval
Neem oil kills on contact and leaves nothing behind once dry. Insecticidal soap needs a day. A synthetic pyrethroid runs 8–12 weeks. Residues can kill the beetles or disguise the scent of the mealybugs
Safe around
Plants, humans and pets. Strictly carnivorous — they do not eat leaves, roots or fruit
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