Occurrence of Papaya mealybug, Paracoccus marginatus as an emerging pest of Hibiscus mutabilis and its predator from Terai region of West Bengal

Abstract

The present study reports, the first record of papaya mealybug, Paracoccus marginatus Williams and Granara de Willink as a serious pest of Hibiscus mutabilis Linn. from the Terai region of West Bengal, India. Studies were conducted during the summer at Pundibari, Coochbehar and observed that about 80-90 per cent plants and 49.49 per cent leaves were infested by this sap sucker. Critical observation revealed that mealybugs as cotton-like masses were seen to accumulate on the above ground portion mainly on tender leaves, twigs and apical buds of plants. Both the nymphs and adults suck the sap and devitalize them. Infested plants also bear a significantly lower number of flowers as well as deformed flowers. The detailed studies on morphology, biology, host range etc. have been discussed in the paper. A lepidopteran predator, the apefly, Spalgius epeus westwood was also observed to be associated with the mealy bug colonies and were found to predate on it. The first, second, third and fourth instar predator larvae devoured 64.8±3.95, 176.2±12.2, 354±18.3 and 504.3±20.6 mealybug eggs/day, respectively, and could be a potential augmentative biocontrol agent of this polyphagous mealybug.