HOST RANGE OF COCONUT RUGOSE SPIRALLING WHITEFLY ALEURODICUS RUGIOPERCULATUS MARTIN

Abstract

Coconut (Cocos nucifera L.) is attacked by a wide variety of insect pests of which rugose spiralling whitefly (RSW), Aleurodicus rugioperculatus Martin has been causing widespread damage in growing major coconut growing districts of Tamil Nadu since 2016 and has been recorded as an invasive pest in coconut. The pest is expanding its host range in economic field and horticultural crop plants besides weed fauna, posing a real threat to farming community. Extensive survey undertaken in Tamil Nadu during 2018 to 2020 to study the expanding host range of RSW which revealed the presence of the pest in about 67 host plants including coconut. Management of the pest through chemical means is highly difficult and the parasitoid, Encarsia guadeloupae has been observed to effectively suppress the pest. Host plants that harbor more Encarsia parasitoids (which are referred as banker plants) would help in biosuppression of the pest. Upon studying the host range, it was found that, the RSW was able to complete its life cycle and successfully emerge as adults in only six hosts viz., coconut, teak, banana, guava, maize and Spanish cherry, while five other hosts viz., Annona muricata, A. squamosa, A. reticulata, Theobroma cacao and Ficus religiosa supported RSW up to its nymphal stage and harboured Encarsia guadeloupae parasitoids in larger numbers. These hosts can be used as banker crops in and around coconut plantations so that the emerging parasitoids will aid in biosuppression of the target pest.