Cryptolaemus montrouzieri Mulsant

Cryptolaemus montrouzieri has been introduced from Australia for the control of Coccus viridis. But the predator has established on many species of mealybugs and green shield scale. In the field its effectiveness was not demonstrated until a programme was initiated at Central Horticultural Experiment Station, Chethalli where detailed studies resulted in finding out the methods of its practical use for the suppression of mealybugs on citrus, coffee, grapes, several other fruit crops and ornamentals.

After 15 days of infestation of pumpkins with Planococcus citri they are exposed to a set of 100 beetles for 24 hrs. After exposing the pumpkin is kept back in a cage as described for under production of P. citri. The beetles during the period of exposure feed on mealybugs as well as deposit their eggs singly or in groups of 4-12. The grubs are visible in such cages within a week of exposure to beetles. The young grubs feed on eggs and small mealybugs but as they grow they become voracious and feed on all stages of mealybugs. For facilitating the pupation of grubs dried guava leaves or pieces of papers are kept at the base of each of the cages. The first beetle from the cages start emerging on 30th day of exposure to C. montrouzieri adults. The beetles are collected daily and kept in separate cages for about 10-15 days to facilitate completion of mating and pre-oviposition. The beetles are also fed on diet containing agar powder (1 gm), sugar (20 gm), honey (40 cc) and water (100 cc). The adult beetle diet is prepared by boiling sugar in 70 cc of water, adding 1 gm agar, diluting 40 cc honey in 30 cc of water and adding to the sugar and agar mixture when it comes to boiling point. The hot liquid diet is kept on small white plastic cards in the form of droplets which get solidified on cooling. Such cards containing adult diet can be fed not only to C. montrouzieri but also to many other species of coccinellids. From each cage about 175 beetles are obtained. The emergence of the beetles is completed within 10 days. The cost of production of 100 larvae at 1977 price index was Rs.6/- and at 1992 Rs.60. The cost of production of 100 beetles at 1977 price index was Rs.10 and at 1992 price index Rs.100.

Beetles can also be reared on Corcyra cephalonica eggs but empty ovisacs of Planococcus citri are to be kept for inducing egg laying by the beetles. The beetles are also multiplied on semisynthetic diet which is still in the process of further refinement.