I was working in my garden this evening putting in a new plant that I bought from TopTropicals.com (a true tea bush – Camellia sinensis) when I passed by my Gardenia bush and saw what at first looked like some sort of little fuzzy white caterpillar. What the heck is that I wondered? I had never seen anything like it before. I grabbed my camera to snap a couple of pictures then surfed to Google to do some research. A couple of hours later I found the critter and had my answer!
It turns out that it is the larva of a type of beneficial lady beetle known as the “Mealybug Destroyer”, Cryptolaemus montrouzieri. Cryptolaemus is a small (1/5") black lady beetle with an orange-tan front end and rear-end and has a voracious appetite for mealybugs. They will also feed on aphids, scale, mites, thrips, whitefly, and other soft bodied insects when mealybugs are not present. The adults and larvae feed on all stages of the mealybugs including the honeydew produced by mealybugs. Young Cryptolaemus and larvae prefer mealybug eggs and smaller stages of the mealybug. This beetle was imported into the United States in 1891 from Australia by one of the early biological control pioneers, Albert Koebele, to control citrus mealybug in California.
C. montrouzieri larvae are up to ½” long and are white with a wax like covering. The pupae are found in sheltered places such as stems and the underside of leaves. Adult female beetles lay their eggs among the cottony egg sack of adult female mealybugs. Eggs hatch into larvae in about 5 days at 80F. These larvae, which have a waxy covering makes them superficially resembles mealybugs (the waxy white covering protects them from being attacked by ants). It takes another 24 days for these beetles to go through three larval stages and a pupal stage before they become adults. After four days, adult beetles begin to lay up to 400 yellow eggs during their two month life span.
If you find what you think are mealybugs on your plants, look again more carefully. Mealybug Destroyer is larger than the mealybug and does not produce a waxy white coating on leaves and stems like mealybugs do. Also look carefully among the leaves for adult beetles to verify that this beneficial garden pest controller is present. Please do not use insecticides on them and let them do their job. You can buy the Mealybug Destroyer online from Arbico Organics and other places, but at $55.95 for 25 adults (that’s over $2 for each beetle!) you should count yourself lucky that they are in your garden and leave them alone to control your bug problem naturally!