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In the recent past, exotic whiteflies viz., Aleurodicus rugioperculatus, Paraleyrodes bondari, Paraleyrodes minei and Aleurotrachelus atratus are infesting coconut plantations in India. Based on the damage potential, the predominant species are the rugose spiralling whitefly, A. rugioperculatus and the Bondars nesting whitefly, P. bondari. A study was undertaken to determine the seasonal incidence and population dynamics of these in the new invasion region at Karungalakudi block of Madurai district from 33rd standard meteorological week (SMW) of 2021 to 32nd SMW of 2022. The results indicated that A. rugioperculatus incidence rose considerably from the first week of April (10.9 adults/leaflet) to third week of May (8.3 adults/leaflet; while P. bondari reached maximum during the third week of March (71.99 adults/leaflet) and extended up to first week of June (67.57 adults/leaflet) coinciding with summer months with high temperature and limited precipitation. Subsequently, their incidence declined with the onset of north east monsoon coupled with parasitism by Encarsia guadeloupae and predation by chrysopids from thirdweek of August to fourth-week of December in 2021. The extent of parasitism by E. guadeloupae on A. rugioperculatus nymphs was positively correlated and ranged from 40% (third week of August, 33rd SMW, 2021) to 84% (second week of June 2022, 24th SMW). Chrysopids revealed a highly significant positive correlation with the incidence. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Wolbachia is a common maternally inherited bacterial endosymbiont of insects. Many species of whiteflies and their endoparasitoids exhibit interspecific variations/ species complexes which can be analysed through the variations between the host and the parasitoid using molecular markers. This study characterized the occurrence of Wolbachia in the whitefly Aleurodicus rugioperculatus and its parasitoid Encarsia guadeloupae. The Wolbachia surface protein(wsp) (450-600 bp) sequenced from the host-parasitoid collected from the field populations at Karnataka was analysed. The comparison of these sequences in the NCBI database through BLAST and ORF analysis revealed the presence of two new sequences infected with Wolbachia from the samples collected on the coconut palms (Cocos nucifera). The genetic relatedness of these has been brought out using the wsp gene through PCR. [ABSTRACT FROM AUTHOR]

Studies were conducted on the incidence, intensity of infestation, infestation grade index and natural enemy complex of rugose spiralling whitefly (RSW) Aleurodicus rugioperculatus Martin infesting coconut palms so as to evolve ecofriendly IPM. RSW incidence was at peak in June 2018 (38.3%), subsequently declined in December 2018 (20.5%), but later attained peak again in March 2019 (47.5%). The pest intensity also showed increasing trend from January 2018 to June 2019. The mean intensity of infestation and infestation grade index were 29.5% and 1.5 (medium), respectively in 2018-2019. The incidence and intensity significantly reduced from 75.5 to 37.7% and 85.7 to 42.9%, respectively on palms treated with ecofriendly IPM practices in 2018-19. Nut yield and net return were also found more in synergy with maximum parasitism (78.5%) by the aphelinid parasitoid Encarsia guadeloupae Viggiani observed on palms treated with ecofriendly IPM practices. [ABSTRACT FROM AUTHOR]

The rugose spiralling whitefly (RSW) Aleurodicus rugioperculatus Martin is an invasive pest of coconut in India. The behavioural response of its parasitoid Encarsia guadeloupae Viggiani (Hymenoptera: Aphelinidae) on healthy and RSW infested host plants of coconut, banana, sapota and guava has been assessed in this study using a six arm olfactometer. Parasitoids' attraction was maximum with the infested banana leaves (1.62± 0.28) followed by coconut (1.28± 0.20), guava (1.05± 0.24) and sapota (0.82± 0.24). The results obtained also reveal that E. guadeloupae can be mass reared on banana plants infested with RSW nymphs to enable better mass production of the parasitoid. [ABSTRACT FROM AUTHOR]