Biological Suppression of Planococcus citri (Risso) (Homoptera:Pseudococcidae) on Crossandra undulifolia Salisb. in India

The citrus mealybug, Planococcus citri (Risso) (Homoptera: Pseudococcidae) was observed infesting Crossandra undulifolia Salisb. in 2006 at the Indian Institute of Horticultural Research Farm, Bangalore. It is a new host plant for the pest in India and elsewhere. Since the application of conventional insecticides fails to control the mealy bugs, possibilities of its biological control were explored on crossandra. A total of 500 larvae of the Australian ladybird beetle, Cryptolaemus montrouzieri Mulsant were released in an area of 100 sq. metre planted with crossandra. Following the release of C. montrouzieri, the plants were almost cleared of the mealybugs after 3 months. Since the weather parameters such as maximum and minimum temperatures, relative humidity and rainfall did not show any significant relationship with the citrus mealybug population on crossandra, the decline in the mealybug population was attributed to the activity of the biotic agents, chiefly C. montrouzieri.