The most commonly used natural enemy of mealybugs are Crypts which are in the ladybug group of beetles. They are predators of mealybugs.

Crypt eggs are laid among mealybug colonies and hatch in 5-6 days at 81 degrees F. The four larval stages have wolly appendages of wax and resemble mealybugs. True legs are barely visible under the larvae.

The larval stages feed on mealybugs and live for a total of 12 - 17 days. The last larval stage can be longer than 1.3 cm (1/2 inch). Crypts pupate in sheltered places on stems or on greenhouse structures. Adults emerge after 7-10 days and also feed on mealybugs. Adult Crypts are dark brown with orange heads and tails, and are about 4mm (1/6 inch) long. Adults mate, and within 5 days females will begin to lay eggs (a total of 400-500 eggs in thir 50-day lifetime.) The life cycle requires about 31 days at 81 degrees F and 45 days and 70 degrees F.

Adults and young larvae prefer to feed on mealybug eggs, but the older larvae will feed on any mealybug stage. The adults can fly and cover large areas to search for food. If food is scarce, crypts will fly off in search of other related insects such as aphids and soft scales. A single larva can consume 250 small mealybugs.

Apply 5 Crypts per infested plant or 2-5 Crypts per square yard. In orchards release 1,000 - 2,000 per acre for mature fruit trees. Crypts are most effective when mealybug populations are high. Repeated relaeases are advisable.