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The lethal and sub-lethal doses of several novel insecticides, spirotetramat 15.31 OD, flupyradifurone 17.09 SL, and the entomopathogenic fungus Cordyceps fumosorosea strain ICAR-NBAIR Pfu-5, were evaluated on the parasitoid Encarsia guadeloupae and predator Apertochrysa astur. C. fumosorosea at 5 ml/L; spirotetramat 15.31 OD at 1.20 ml/L; C. fumosorosea at 2.5 ml/L + spirotetramat 15.31 OD at 1.20 ml/L were determined to be safer for immature stages and adults of E. guadeloupae and were classified as class I insecticide (harmless). C. fumosorosea at 2.5 ml/L + flupyradifurone 17.09 SL at 1.25 ml/L and flupyradifurone 17.09 SL at 2.5 ml/L were found to be slightly harmful (Class II insecticide) to adult stages of E. guadeloupae. C. fumosorosea at 5 ml/L; spirotetramat 15.31 OD at 1.20 ml/L; C. fumosorosea at 2.5 ml/L + spirotetramat 15.31 OD at 1.20 ml/L and C. fumosorosea at 2.5 ml/L + flupyradifurone 17.09 SL at 1.25 ml/L demonstrated minimal effect on larvae and adults of A. astur and were classified as class I insecticide. In contrast, with the exception of C. fumosorosea at 5 ml/L, all other test insecticides, either individually or in combination, were found to be unsafe for A. astur eggs. Imidacloprid 17.8 SL exhibited slightly harmful effects on larval stages and moderately harmful effects on adult stages of these biocontrol agents and was classified as class II and III insecticide, respectively. This study contributes new tools for use in IPM for the control of rugose spiraling whitefly, in which chemical and biological control strategies are employed concurrently. [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]

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 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]

Parasitoids find their hosts by using cues released by herbivores and their host plants. In crop fields, these semiochemicals could be used for insect pest control by attracting and retaining natural enemies. The hymenopteran aphelinidae endoparasitoid, Encarsia guadeloupae (E. guadeloupae), selectively parasitizes rugose spiralling whitefly (RSW), Aleurodicus rugioperculatus Martin, an invasive pest of coconut in India, thus offering an effective way to improve RSW control under natural field conditions. However, the chemical interactions that occur in between the RSW infected host plants and E. guadeloupae were unknown. Hence, using olfactometer assays and chemical analyses, we investigated the volatile organic compounds (VOCs) mediating attraction of the parasitoid to RSW infested host plants. To investigate the attraction of the E. guadeloupae towards the healthy and RSW infected leaves of coconut (Cocos nucifera L), banana (Musa paradisiaca L) and custard apple (Annona squmosa L), we employed a six-arm olfactometer. The E. guadeloupae preferred the volatile compounds from RSW-infested host plants rather than healthy plants. A higher percent response rate of E. guadeloupae was observed in RSW-infected banana (35.83 %), followed by healthy banana (24.33 %), RSW-infested custard apple (16.33 %), and RSW-infested coconut (9.00 %) leaf volatiles, respectively. The volatile compounds emitted from RSW-infested and healthy plants have been studied using GC–MS with thermal desorption (TD). The results revealed more than 20 volatile compounds belonging to seven chemical classes were identified and characterized from infested plants by RSW. Of these, α-Ocimene, α-Pinene, 3-Carene, trans-α-Ocimene, and (E)-hex-3-ene-2, 5-diol were emitted at higher levels than other compounds its proven through PCA and Heat map analysis. These five compounds elicited the greatest attraction of E. guadeloupae towards RSW damaged plants. The synthetic blend of the above volatiles could be used as attractants to enhance the population of E. guadeloupae to manage RSW under field conditions. • Encarsia guadeloupae , an aphelinid was found effectively suppressing RSW population in natural field conditions. • In the field, RSW-infected bananas had 70.46% parasitization and 86.43% adult emergence of E. guadeloupae. • A higher percent response rate of E. guadeloupae was observed in RSW-infected banana host volatiles. • Higher emissions of α-Ocimene, α-Pinene, 3-Carene, trans-α-Ocimene, and (E)-hex-3-ene-2,5-diol were observed in RSW hosts. • A synthetic blend of these volatiles attracts E. guadeloupae , managing RSW in the coconut ecosystem effectively. [ABSTRACT FROM AUTHOR]

The exotic spiralling whitefly, Aleurodicus dispersus Russell, was observed to infest several ornamentals including rose, hibiscus, poinsettia and acalypha in and around Bangalore. Efforts were made to colonize the aphelinid parasitoid, Encarsia guadeloupae Viggiani, during 2002 - 2003 on the above ornamentals infested with the spiralling whitefly. A total of five predators, namely, Axinoscymnus puttarudriahi Kapur and Munshi, Cryptolaemus montrouzieri Muls., Anegleis cardoni (Weise), Mallada astur (Banks) and Cybocephalus sp. were observed on the spiralling whitefly on these ornamentals during the study but their impact on the spiralling whitefly was negligible. Inoculative releases of E. guadeloupae were made on rose (156 adults), hibiscus (179 adults), poinsettia (124 adults) and acalypha (247 adults). Encarsia guadeloupae was recovered within a month after its release with 3.43-32.94% parasitism. A steady decline in the population of spiralling whitefly was observed on these ornamentals. Encarsia guadeloupae was found to be the only parasitoid encountered throughout the study and the total parasitism steadily increased up to 96.00% on rose, 86.40% on hibiscus, 90.40% on poinsettia and 39.86% on acalypha at six months from release. Parasitism by E. guadeloupae was significant and negatively correlated with the population of spiralling whitefly on all the four ornamentals.

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]

The spiraling whitefly Aleurodicus dispersus (Russell) is an insect pest that causes substantial damage to ornamental plants, shade trees and food crops. It was first observed in Benin in 1993. Two host specific parasitoids, Encarsia dispersa and E. guadeloupae, fortuitously introduced with its host, were recovered in the second half of 1993 in Southern Benin. Survey results from 1993 to 1995 (already published) showed the decline in the population of A. dispersus due to the parasitoids, and the spread from Cotonou (6°10′N) in a northern directions of both parasitoids and their host. Results from similar field surveys from 1996 to 2003 document that the spiraling whitefly and both its parasitoids spread to Natitingou (10°20′N, 540 km) in 1995 and Bembereke (10°14′N) in 1996, whereby E. dispersa arrived within less than a year of its host and quickly became dominant in the two localities on the northern front. In subsequent years, the parasitoids established their geographical niches, with E. dispersa being more abundant (up to 89%) in the coastal south bellow latitude 7°30′N and E. guadeloupae (up to 84%) in the north between latitudes 7°30′ and 10°30′N. We conclude that the gradual replacement observed over ten years and over 500 km has to do with longitudinal shifts in the length and severity of the dry season and the higher susceptibility to these conditions by E. dispersa. [ABSTRACT FROM AUTHOR]

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]