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Rugose Spiralling Whitefly (RSW) (Aleurodicus rugioperculatus Martin; Aleurodidae: Hemiptera) began invading India in 2016 from Southern Peninsula, later expanded to several other states of the country. As a result, India now considers RSW to be a serious invasive insect pest on coconut. To understand its severity in Tamil Nadu, an extensive field survey was taken up, which revealed that the RSW abundance was in decreasing trend in Cauvery Delta Zone followed by Southern zone, High Rainfall zone and Western zone. The frond damage was lowest in Southern zone (Madurai, 14.43%) and statistically on par with Western zone (Coimbatore, 28.76%) whereas highest frond and leaflet damage was observed in Cauvery Delta zone (Pudukottai, 82.3 and 72.66% respectively). The aphelinid parasitoid, Encarsia guadeloupae Viggiani adult's emergence was high in Coimbatore district with a parasitization rate of 93.25 per cent. In morphometric studies, many morphological parameters measured in A. rugioperculatus adult male and female were high in Pudukkottai population. Score plot analysis of both sexes of A. rugioperculatus clearly showed that no biotype existed. The nucleotide sequence of RSW was deposited in GenBank as OP 295,073 which had > 98 per cent similarity with those DNA sequences submitted in NCBI database OP0295073, OP414609 and MK 883,219. Five years down the infestation of RSW on coconut, the severity has been reduced drastically with the subsequent buildup of the parasitoid E. guadeloupae. Thus conserving E. guadeloupae through the establishment of "banker plants" and refraining from insecticide spraying can effectively suppress RSW in the long term. [ABSTRACT FROM AUTHOR]

The rugose spiraling whitefly, Aleurodicus rugioperculatus Martin (Hemiptera: Aleyrodidae), is an invasive pest on coconut and other horticultural crops. An indigenous nymphal parasitoid, Encarsia guadeloupae Viggiani (Hymenoptera: Aphelinidae), is found to co-exist as a promising natural enemy of A. rugioperculatus. The bacterial community associated with whiteflies was reported to influence the parasitism efficiency of different parasitoids. Hence, the present investigation was carried out to test the role of the associated bacterial community of A. rugioperculatus on the parasitic efficiency of E. guadeloupae through the antibiotic-curing method. The identity of the test insects viz., A. rugioperculatus and E. guadeloupae were confirmed using the mtCOI gene before carrying out the investigation. The parasitization efficiency of E. guadeloupae was recorded on symbiotic (untreated) and antibiotic-treated A. rugioperculatus nymphal stages reared on four host plants viz., coconut, banana, sapota, and guava. The antibiotics Carbenicillin @ 100 µg ml− 1 and Ciprofloxacin @ 5 µg ml− 1 were combined and fed to A. rugioperculatus adults by parafilm feeding chamber method to eliminate the possible cultivable bacteria. The results revealed the complete elimination of cultivable bacteria in the F4 generation, and hence, the F4, F5, and F6A. rugioperculatus populations were tested for their susceptibility to parasitization by E. guadeloupae. Higher parasitism (74.70%), lower emergence rate (59.70%), and longer developmental time (21.00 days) of E. guadeloupae were observed in the antibiotic-treated population than in untreated A. rugioperculatus population of the F6 generation. Elimination of bacterial symbionts through antibiotic treatment might have suppressed the immunity and nutritional status of the whiteflies and led to more susceptibility toward parasitoid attack, poor parasitoid emergence and longer developmental time of E. guadeloupae on antibiotic-treated A. rugioperculatus. Our investigation revealed that antibiotic curing of bacterial symbionts associated with host insects had a minimal impact on the parasitic efficiency of E. guadeloupae. [ABSTRACT FROM AUTHOR]

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]

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]

The present study investigated the biology and morphometric analysis of rugose spiralling whitefly (RSW), Aleyrodicus rugioperculatus on coconut under mini net house condition at Department of Agricultural Entomology, Tamil Nadu Agricultural University -Coimbatore during 2019-2020. The biology of rugose spiralling whitefly was studied by clip cage method and morphometrics were done using Leica image analyser. Total lifecycle of rugose spiraling whitefly was 56.23 ± 2.20 days. Developmental period of egg, nymphal, pupal and adult period was 8.47 ± 0.26, 17.46 ± 0.76, 10.30 ± 0.29 and 20.00 ± 1.00 days, respectively. In morphometrics, Length and width of egg (0.31 ± 0.01 mm and 0.11± 0.02 mm), nymphal (0.94 ± 0.01 mm and 0.82 ± 0.01 mm), pupal (1.23 ± 0.01 mm and 1.00 ± 0.01 mm) was recorded. A nymphal parasitoid, Encarsia guadeloupae can be potential natural enemy for effective management of rugose spiraling whitefly. [ABSTRACT FROM AUTHOR]

Field surveys were conducted on the parasitoids of rugose spiralling whitefly (RSW), Aleurodicus rugioperculatus Martin (Hemiptera: Aleyrodidae) during 2018-20 in coconut growing districts of Tamil Nadu. The parasitoid, Encarsia guadeloupae Viggiani (Hymenoptera: Aphelinidae) was observed on A. rugioperculatus occurring in hosts viz., coconut, banana and custard apple. Among all crops, RSW infesting banana had maximum parasitisation (70.83%). Adults of E. guadeloupae are small (0.6-0.7 mm) brown in colour with body length and width of0.675±0.014 mm and 0.256±0.010 mm. The natural parasitism by E. guadeloupae was ranging from 31.60% (August 2018) to 57.60% (December 2018). Correlation coefficient of E. guadeloupae with A. rugioperculatus population showed that had negative correlation with A. rugioperculatus population E. guadeloupae In the case of coconut trees based on heights the parasitization potential of E. guadeloupae was 5-10 feet height trees with maximum level of parasitisation (61.39%) followed by 10-15 feet coconut tree with 52.77%. In banana leaf position impact on E. guadeloupae emergence from parasitized, rugioperculatus was 47.93% in 6th leaf (from the top) of banana tree followed by 10th leaf (47.12%). This is because preferred stage of RSW mostly found in top leaves than the old leaves where mostly later instar stages will be available. [ABSTRACT FROM AUTHOR]

Abstract: Encarsia guadeloupae Viggiani (Hymenoptera: Aphelinidae) is a minute, obligate endoparasitoid against the spiraling whitefly Aleurodicus dispersus nymph. The external morphology and distribution of the antennal sensilla of female E. guadeloupae were observed by scanning electron microscopy. Antennae of female E. guadeloupae were geniculate in shape, which consist of scape with a radicula, pedicel, and flagellum. Eight morphological sensilla types were recorded in the females: nonporous sensilla chaetica (CH-NP) and nonporous sensilla trichodea (ST-NP); uniporous sensilla chaetica (CH-UP) and uniporous sensilla trichodea (ST-UP) with a tip pore, basiconic capitate peg sensilla with numerous pores open at the bottom of the grooves; multiporous sensilla placoid (MSP) with the multiporous cuticular structure; uniporous rod-like sensilla (RO-UP) with robust grooved surfaces and the tremendous apical hole; nonporous finger-like sensilla (FI-NP) with abundant pimples at the bulgy, mortar-shaped short stalk. In order to further explore the host location mechanisms and courtship behavior of E. guadeloupae, the possible roles of the antennal sensilla of this species were discussed. [Copyright &y& Elsevier]

A field study conducted during 2000-2001 on banana plantation located at Bangalore Rural district revealed that the population of the spiralling whitefly Aleurodicus dispersus Russell declined from 116.85 per 25-cm 2 leaf area in March 2000 to 1.10 per 25-cm 2 leaf area in December 2001. During the study period, a total of seven natural enemies were observed. The aphelinid parasitoid Encarsia guadeloupae Viggiani was the only major natural enemy encountered on the spiralling whitefly causing 20.70% parasitism in January 2000, which had increased to 95.68% by December 2001. The density of the spiralling whitefly was positively correlated with maximum temperature and negatively correlated with relative humidity and the parasitism by E. guadeloupae. The multiple regression model showed that about 67.94% of the variation in the whitefly density could be accounted for by parasitism only. [ABSTRACT FROM AUTHOR]