Page Intro: Cryptolaemus montrouzieri, also known as “Crypts” or “Mealybug Destroyers” and the name says it all. On this page you will find a description, life-cycle info, benefits, drawbacks, scouting info, advisories, usages, beyond the page, and other good stuff such as ordering.
Description
Like Hippodamia convergens, the popular aphid predators, C. montrouzieri are ladybug beetles. Unlike their relative, though, these beetles are not wild-collected, do not aggregate and do not disappear just after release.
Crypts, with their shiny black body and dull-orange head and thorax, definitely prefer to dine on mealybugs (especially young ‘uns). They can clean up large populations. However, as most beetles are, C. montrouzieri are very opportunistic and will eat pests other than mealybugs: other scale insects (their crawlers or immature forms), insect eggs, etc. I do not recommend using these beetles for other pests, though. I believe control of other pests might not be obtainable with typical Crypts releases. Coincidental cross-predation should be regarded as a bonus of the application and nothing more.
With mealybugs, though, these beetles have proven themselves more than worthy. My company’s customers have typically reported phenomenal results with their use. Especially the interiorscaper and botanical garden customers.
C. montrouzieri are shipped as pre-fed, pre-mated, insectary-reared (for the citrus industry). Some popular prey of these beetles include: the citrus mealybug (Planococcus citri); the comstock mealybug (Pseudococcus comstocki); the obscure mealybug (Pseudococcus obscurus); the solenopsis mealybug (Phenacoccus solenopsis); the Mexican mealybug (Phenacoccus gossypii) and many other related species, even the long-tailed mealybug (Pseudococcus longispinus) can be consumed with greedy abandon, but only if it is present with another species which produce cottony egg-masses (see Advisories). [Intro]
Life-style
The large 5 mm. Australian, adult female beetles lay their eggs in the cottony egg-masses produced by the pests — one egg per mass, usually, and up to 10 of them per day, for up to 50 days! The eggs hatch into white, shaggy-coated larvae which, to the inexperienced, look like mealybugs (a wolf in sheep’s clothing). These, too, are fierce predators, growing up to 1 cm. long and consuming 250 or so small mealybugs and their eggs (they’ll always eat the youngest first).
The life-span of these predators is roughly ~3 weeks in their immature stages, then around ~1 month as adults. The conditions for optimum performance will be between 64-91°F with a relative humidity of 70% or greater. But these are optimum conditions, and not necessarily a prerequisite of successful implementation. Please note, however, significantly cooler or warmer temperatures and humidity fluctuations may hamper reproduction and development a certain degree. [Intro]
Benefits
Considering how good the performance of these predatory beetles is, they are a cost-effective solution to your mealybug problems.
These beetles are usually easy to scout (see Scouting). [Intro]
Drawbacks
They won’t fly at temperatures below 56°F. They will still work, they don’t undergo diapause (a quiescent state, hibernation), they will just do so more slowly and inefficiently.
Another drawback is they seem to be a temporary fix in interiorscapes, providing outstanding results, but for only 8-26 weeks. The adult beetles leave when they are nearly done, and their young must die.
But, thinking about it, isn’t all pest control just temporary? Consequentially, and because my firm’s customers say that the Crypts are still the most economical and easiest control, I have to stop and wonder if there are any significant drawbacks concerning the use of this species. Perhaps not.
Perhaps so! C. montrouzieri, in the past — 1997 mostly — have sometimes been difficult to obtain due to rearing difficulties. But Crypts are much too important a biocontrol agent to allow such things to continue. Demand is very high and, at least at the time this is being written, supply problems have stayed a thing of the past. [Intro]
Scouting
Adult beetle presence, larval presence, reduction of pest numbers, “exploded” mealybug egg-masses. These are all signs that Crypts are hard at work.
Now, having written that, a lot of interiorscapers are probably wondering if this easy-to-spot predator will be noticed by their clients. The answer is probably not. I’ve never heard of a complaint about Crypts in their planting(s) — okay, with exception to this one instance of these beetles being used in a balcony planting hanging over a lobby of a doctor’s reception area. Trailing pothos was being treated with Crypts, and they were working, but one day one of the beetles’ larvae fell from the balcony into the hair of a patient waiting in the reception area. She freaked at first, but was okay with the whole thing when the facts were explained to her. I strongly suggest that interiorscape contractors do consult with their clients before putting in the predators, and explain to them the facts (so no one will freak out). [Intro]
Advisories
Crypts need to lay their eggs in the cottony egg-masses of their prey (as discussed under Description and Life-style). Since long-tailed mealybugs don’t lay eggs, but rather give live-birth, as aphids do, they provide no cottony masses in which the beetles can lay their eggs. This is not a problem if your site has more than one species (assuming the other species does produce the egg-masses). Crypts will eat immature long-tailed mealybugs with great joy, they just can’t reproduce on them.
A long-tailed-mealybug-only infestation can be overcome a couple of different ways:
Long-Tailed Mealybug Control Options
- You can place little bits of synthetic quilt batting (available from craft stores) amongst the long-tailed mealybug populace. (Avoid cotton balls as they may contain pesticide residues.) I’m not completely sure how well this works, but a number of folks have tried it, experimentally, and reported satisfactory results. Also, try placing white 3" x 5" index cards, halved, by groupings of the pests to lure the beetles in.
- Employ the Chrysoperla spp. (green lacewings) at the site. I’ve been told on numerous occasions that they do an excellent job. Use only the eggs or the larvae, however. Preferably the larvae. I don’t think the adults will do too well as they’ll be seeking out aphid colonies near which they can lay their eggs.
Aside from misting the site with water before releasing and doing so in the evening (sometimes not necessary in interiors), there are other things you can do to ensure the maximum number of beetles stick around. Flowering, pollen producing plants are a big plus to Crypts).
Pollen isn’t the only thing these beetles will eat. They will also consume mealybug honeydew; they produce a lot. A honeydew substitute product may help encourage the beetles. Most suppliers ship Crypts, as mine does, with an in-flight snack of the stuff. And they never complain about the airline’s cuisine.
Ants, if present, should be controlled. They will defend mealybugs from predators and parasites to protect their honeydew/excrement food, blah! Use barrier products or boric acid products to control the ants.
In 1996, I was contacted by a popular professional interiorscape writer, speaker and consultant, Linnaea Newman, with a new and ingenious way to release Crypts in interiorscape trees: Find a long bamboo or wooden pole with an approximate diameter of three-sixteenths to one-quarter-inch; insert one end of the pole through the pre-manufactured hole in my company’s jars’ lids and into the jar of beetles, being careful not to injure any of them; the beetles will climb up the pole to the other end [if it’s not too hot, they may fly off the pole (but should still make it to the foliage — eventually)], which should be tucked into the tree’s foliage. I’ve told some of my company’s customers of this technique and encouraged them to try it. They did and reported excellent results. We now suggest everyone try it. Thanks Linnaea!
Last advisory: don’t wear white clothing when you’re releasing C. montrouzieri. They are attracted to white and light colors and may find you irresistible. Also watch your sticky traps, if you’re using them. If you’re catching too many beetles, remove the traps from the site or set them out for only 2-3 days per week. [Intro]
Usages
Where can’t they be used would a more appropriate question. I’ve seen the successful implementation of this species in just about every conceivable situation. Most with equal success. [Intro]
Beyond the Page
It should be noted that Chrysoperla spp. can have an impact on long-tailed mealybugs. and may even be a more suitable choice. Check out the Chrysoperla spp. page for more information about that predator. [Intro]
Rates, Instructions, and Purchase
Need more information? Check out our release rates or our short-term storage, handling, and release instructions. You may also purchase C. montrouzieri. [Intro]
