Whitefly Species Research Articles

Microbiome diversity and composition in Bemisia tabaci SSA1-SG1 whitefly are influenced by their host’s life stage

Within the Bemisia tabaci group of cryptic whitefly species, many are damaging agricultural pests and plant-virus vectors, conferring upon this group the status of one of the world’s top 100 most invasive and destructive species, affecting farmers' income and threatening their livelihoods. Studies on the microbiome of whitefly life stages are scarce, although their composition and diversity greatly influence whitefly fitness and development. We used high-throughput sequencing to understand microbiome diversity in different developmental stages of the B. tabaci sub-Saharan Africa 1 (SSA1-SG1) species of the whitefly from Uganda. Endosymbionts (Portiera, Arsenophonus, Wolbachia, and Hemipteriphilus were detected but excluded from further statistical analysis as they were not influenced by life stage using Permutational Multivariate Analysis of Variance Using Distance Matrices (ADONIS, p = 0.925 and Bray, p = 0.903). Our results showed significant differences in the meta microbiome composition in different life stages of SSA1-SG1. The diversity was significantly higher in eggs (Shannon, p = 0.024; Simpson, p = 0.047) than that in nymphs and pupae, while the number of microbial species observed by the amplicon sequence variant (ASV) was not significant (n(ASV), p = 0.094). At the phylum and genus levels, the dominant constituents in the microbiome changed significantly during various developmental stages, with Halomonas being present in eggs, whereas Bacillus and Caldalkalibacillus were consistently found across all life stages. These findings provide the first description of differing meta microbiome diversity in the life stage of whiteflies, suggesting their putative role in whitefly development.

Invasive Whitefly (Hemiptera: Aleyrodidae) Complex and Diversity in Coconut Landscapes in Tamil Nadu

Abstract Coconut, Cocos nucifera L., in Tamil Nadu, India, was invaded by four whitefly (Hemiptera: Aleyrodidae) species between 2016 and 2019, increasing the total to six, along with Aleurodicus dispersus Russell and Aleurocanthus arecae David and Manjunatha. We examined the complexity and diversity of whiteflies in coconut across different agroclimatic zones of Tamil Nadu and found high and low damage levels by whiteflies at Veppankulam (70.4%) and Rameswaram (11.0%), respectively. The rugose spiraling whitefly, Aleurodicus rugioperculatus Martin, was the most dominant species but was effectively managed by the parasitoids Encarsia guadeloupae Viggiani and E. dispersa Polaszek, with the highest rate parasitism of 83.8% at Aliyar Nagar and the lowest (2.9%) in the Kanchipuram district. Aleurodicus rugioperculatus and Bondar’s nesting whitefly, Paraleyrodes bondari Peracchi, have spread throughout Tamil Nadu. The population of A. rugioperculaus was high at Veppankulam and that of P. bondari was higher at Dharmapuri (28.6 and 31.1 adults/leaflet, respectively). All five invasive whitefly species in coconut were found only in 7 of 34 locations—Coimbatore, Sirumugai, Salem, Dharmapuri, Krishnagiri, Vellore, and Erode. Paraleyrodes minei Iaccarino and Aleurotrachelus atratus Hempel were distributed in the northwestern zone adjoining the western ghats of Tamil Nadu. Coconut plantations at Sirumugai (western ghats) supported the most diverse collection of whiteflies, with 0.61 and 1.09 Simpson and Shannon diversity indices. Among the 29 districts, adjoining Dindigul and Theni districts showed the highest Bray–Curtis Similarity Matrix. Butterfly palm, Dypsis lutescens H. Wendel, custard apple, Annona squamosa L., and guava, Psidium guajava L., are whitefly hosts in coconut landscapes.

Comparative prey predation ability of big-eyed bug Geocoris ochropterus (Fieber) (Hemiptera: Geocoridae)

We investigated the predation ability of big-eyed bugs Geocoris ochropterus on different single prey species of thrips, whiteflies, and aphids. Results indicated that G. ochropterus adults consumed the highest number of aphids per day (33.6 ± 3.35). First instar nymphs of G. ochropterus showed low ability to consume prey, while from second to fifth instar nymphs showed high ability to consume prey with significant differences. The number of eggs deposited per female fed on whiteflies was significantly different larger than other prey types. In addition, development time of Geocoris ochropterus nymphs first to fourth instar was longest when fed on aphids and significantly different among prey types. Results suggest that G. ochropterus consumed the highest numbers of aphids, with the order of preference aphids > whiteflies > thrips.

Comparative evolutionary analyses of eight whitefly Bemisia tabaci sensu lato genomes: cryptic species, agricultural pests and plant-virus vectors

BackgroundThe group of > 40 cryptic whitefly species called Bemisia tabaci sensu lato are amongst the world’s worst agricultural pests and plant-virus vectors. Outbreaks of B. tabaci s.l. and the associated plant-virus diseases continue to contribute to global food insecurity and social instability, particularly in sub-Saharan Africa and Asia. Published B. tabaci s.l. genomes have limited use for studying African cassava B. tabaci SSA1 species, due to the high genetic divergences between them. Genomic annotations presented here were performed using the ‘Ensembl gene annotation system’, to ensure that comparative analyses and conclusions reflect biological differences, as opposed to arising from different methodologies underpinning transcript model identification.ResultsWe present here six new B. tabaci s.l. genomes from Africa and Asia, and two re-annotated previously published genomes, to provide evolutionary insights into these globally distributed pests. Genome sizes ranged between 616—658 Mb and exhibited some of the highest coverage of transposable elements reported within Arthropoda. Many fewer total protein coding genes (PCG) were recovered compared to the previously published B. tabaci s.l. genomes and structural annotations generated via the uniform methodology strongly supported a repertoire of between 12.8—13.2 × 103 PCG. An integrative systematics approach incorporating phylogenomic analysis of nuclear and mitochondrial markers supported a monophyletic Aleyrodidae and the basal positioning of B. tabaci Uganda-1 to the sub-Saharan group of species. Reciprocal cross-mating data and the co-cladogenesis pattern of the primary obligate endosymbiont ‘Candidatus Portiera aleyrodidarum’ from 11 Bemisia genomes further supported the phylogenetic reconstruction to show that African cassava B. tabaci populations consist of just three biological species. We include comparative analyses of gene families related to detoxification, sugar metabolism, vector competency and evaluate the presence and function of horizontally transferred genes, essential for understanding the evolution and unique biology of constituent B. tabaci. s.l species.ConclusionsThese genomic resources have provided new and critical insights into the genetics underlying B. tabaci s.l. biology. They also provide a rich foundation for post-genomic research, including the selection of candidate gene-targets for innovative whitefly and virus-control strategies.

Seasonal Presence of White Fly Species on Jujube Trees in Nineveh Governorate

The study was conducted in the gardens of Mosul University from September 2019 to September 2020 in order to determine the types of white flies that infest Jujube trees and their seasonal activity. The results showed that Jujube trees, Zizyphus spina Christi, were infected with the following species: Acaudaleyrodes rachipora (Singh), Aleurolobus marlatti (Quan), and Aleuroclava jasmini (Takahashi). The percentage of leaf infection was highest in November, followed by September and August with an average 98.95, 94.85 and 94.63%, respectively. The insect preferred upper surface of the leaf than its lower surface, as the average number of nymphs was 15,11, and 1,39 nymphs/leaf, respectively, and the number of nymphs peaked during the autumn months. Direction had no effect on the rate of leaves infection, and no significant differences appeared between the treatments, while the density of nymphs in the leaves was affected by the direction factor, as the southern direction was significantly superior at a rate of 18.85 nymphs/leaf, and no significant differences were recorded between the other three directions. The results of the weekly catch also showed that the density of adults ranged between (1.28-168) adult /trap, peaking in October, while the adult were absent from the traps during January and February. Some predators were seen preying on the stages of the white fly, Lasiochilus pallidulus (Reuter), Oenepia conglobate (L.), Chrysoperla carnea (Stepheus).

First Report of Three Invasive Whitefly Species (Aleyrodidae: Hemiptera) from West Bengal, India

Invasive insect pests are alien or exotic organisms. These are introduced species to an environment outside their original or native habitat and have an immense power of dispersal and adaptation. Invasive species are responsible for reducing or minimizing the productivity of the crops and thereby creating huge economic losses. Due to the small size and the ability to be attached to the host plants, the invasive whitefly species have been introduced to several countries through movement of different plants during trade. Eight such species have invaded and been reported from India. But only three such species – Spiralling whitefly (Aleurodicus dispersus Russell), Rugose spiralling whitefly (Aleurodicus rugioperculatus Martin) and Bondar's nesting whitefly (Paraleyrodes bondari Peracchi) – have been reported from West Bengal, till date. Moreover, as per available literature, there is no report of the other invasive species from West Bengal. Based on the present study, the existence of three invasive whitefly species – Solanum whitefly, Aleurothrixus trachoides (Back), Palm infesting whitefly, Aleurotrachelus atratus Hempel and Woolly whitefly, Aleurothrixus floccosus (Maskell) – is reported for the first time from West Bengal. Mitochondrial cytochrome c oxidase sub unit I (COI) gene sequencing was done for molecular characterization of these species to confirm their identity. Regarding host plant preference, woolly whitefly and solanum whitefly showed clear affinity towards guava and chilli, respectively, whereas palm infesting whitefly preferred coconut. This report is going to be the first ever document of invasion by the above-mentioned three exotic whitefly species from West Bengal.

Discovery of the Puparia of a Whitefly Species Found on Malvaceae in the Pliocene Rajdanda Formation, Jharkhand, Eastern India

A new genus and species of fossil whitefly, Praealeurolobus indicus gen. et sp. nov., is described and illustrated based on puparia found on leaves of a malvaceous plant from the Pliocene Rajdanda Formation in Eastern India. It is the first record of whitefly puparia on leaves from the Neogene deposits of Asia and the second taxon formally named and described from such adpression fossils. The cephalothorax of some of the puparia has a large, irregularly shaped hole with jagged edges, typical of the emergence holes of parasitoids of modern-day whiteflies and represents the earliest record of parasitism on whiteflies. This finding enriches our knowledge of the fossil record of Aleyrodidae in connection with allied fossils and provides new insight into the ecological interactions of the palaeobiota and taphonomy of fossils preserved in the Pliocene Rajdanda Formation.

Taxonomic Revision of Tribe Aleurocanthini Takahashi 1954 stat. rev. Using Consortium Gene Analysis (Mito-Nuclear-Primary Endosymbiont) with the First Evidence for Mitochondrial Recombination in Whitefly (Hemiptera: Aleyrodidae)

The discovery of the Aleurocanthus cf. Aleurocanthus spiniferus (Tea spiny whitefly spiniferus morphotype; previously found in Tokyo) for the first time in Shizuoka Prefecture raised the possibility that this species had invaded Honshu Island, Japan. Unlike the allied species, Aleurocanthus spiniferus and A. camelliae, which have been intercepted from China to Japan, the origin of the current species remains unclear. Despite the status of this species as a minor pest on the ornamental plant, Eurya japonica, the cryptic diversity among the black spiny whitefly is fascinating to be elucidated, specifically how the primary endosymbiont of whiteflies, Portiera aleyrodidarum, coevolved and contributed to the classification of whiteflies. The current study examines the taxonomic status of five species of whiteflies, i.e., A. spiniferus (Quaintance), Aleurocanthus aff. A. camelliae, Aleurocanthus cf. A. spiniferus, A. camelliae Kanmiya and Kasai, Aleurotrachelus camelliae Kuwana, and A. ishigakiensis Takahashi. Using consortium molecular typing targeting mitochondrial DNA (COI and 16S of mitoribosome), the nuclear gene (ITS1), and the ribosomal gene of Portiera, the phylogenetic clustering analysis has been conducted and revealed that the genus Aleurotrachelus sensu lato was clustered together with Aleurocanthini Takahashi, 1954 stat. rev. and reinstated Crenidorsum ishigakiensis comb. nov. due to crescent-shaped scallops being clearly defined. The current study also unveiled several putative species in the A. spiniferus species complex, molecularly. In addition, the recombination event was not detected in Portiera but has been detected in the mtCOI genes of the A. spiniferus cryptic species and the A. woglumi sequences deposited in the NCBI database. The mitochondrial recombination gives an insight into the speciation process among this species complex.

A new species of Aleurolobus Quaintance & Baker, 1914 (Hemiptera, Aleyrodidae) from China infesting Murrayaexotica L.

A new whitefly species, Aleurolobusrutaesp. nov., collected on Murrayaexotica (Sapindales, Rutaceae) leaves in the Maolan National Nature Reserve, Guizhou, China, is described and illustrated. Some of the individuals were infected with Aschersoniaplacenta, an entomopathogenic fungus. The insect is circular in shape and characterized by a very wide submarginal region, and the submarginal furrow is almost continuous, with only a small break at the caudal furrow. Anterior and posterior marginal setae are absent, but setae are present on the 8th abdominal segment. Thoracic and caudal tracheal folds are discernible.

Unraveling different begomoviruses, DNA satellites and cryptic species of Bemisia tabaci and their endosymbionts in vegetable ecosystem.

Bemisia tabaci species complex contains more than 46 cryptic species. It has emerged as an important pest causing significant yield loss in many cultivated crops. This pest is also a vector for more than 100 species of begomoviruses, that are a major threat for the cultivation of many crops in different regions of the world. The relation between cryptic species of the B. tabaci species complex and associated begomoviruses that infect different crops remains unclear. In the present study, four cryptic species (Asia I, China 3, Asia II 5 and Asia II-1) of B. tabaci and four associated endosymbionts (Arsenophonus, Cardinium, Rickettsia and Wolbachia) were identified in different vegetable crops. The vector-based PCR detection revealed five different begomoviruses such as okra enation leaf curl virus (OELCuV), tomato leaf curl Palampur virus (ToLCPalV), squash leaf curl China virus (SLCCNV), chilli leaf curl virus (ChiLCuV), and tomato leaf curl New Delhi virus (ToLCNDV). Of these begomoviruses, the maximum infection rate was observed (9.1%) for OELCuV, followed by 7.3% for ToLCNDV. The infection rate of the other three viruses (SLCCNV, ChiLCuV, ToLCPalV) ranged from 0.9 to 2.7% in cryptic species of B. tabaci. Further, each cryptic species was infected with multiple virus species and the virus infection rate of Asia I, Asia II-5, China 3 and Asia II-1 was 21.2%, 15.1%, 15.1% and 0.6% respectively. Similarly, in case of betasatellites the highest infection rate was 12% for ToLCBDB, followed by 6% for OLCuB and PaLCB. With regard to alphasatellites, the highest infection rate was 18.2% for AEV and 3% for CLCuMuA. This study demonstrates the distribution of cryptic species of whitefly and their endosymbionts, and associated begomoviruses and DNA satellites in vegetable ecosystem. We believe that the information generated here is useful for evolving an effective pest management strategies for vegetable production.

Determination of Whitefly Species (Hemiptera: Aleyrodidae) in Southeastern Anatolia Region

Türkiye’nin tüm bölgelerinde tespit edilen Beyazsinek (Hemiptera: Aleyrodidae) türleri üzerinde yapılan taksonomik bir çalışmadır. Güneydoğu Anadolu Projesi (GAP) faliyete başlamasıyla artan bitki türü çeşitliliği ve tüm yıl ürün alınabilmesimesinden kaynaklı olarak tüm yıl varlığını koruyan bir zararlı konumuna gelmiştir. Ayrıca tarımsal sulamadan dolayı artan nem oranı Beyazsinek yoğunluğu artırmış olup bu nedenle tarımsal ürünlerde ciddi zarar verdiği için Güneydoğu Anadolu Bölgesi için önemli bir zararlı olmuştur. 2019-2022 yılları arasında Güneydoğu Anadolu Bölgesi’nde bulunan Şırnak, Siirt, Batman, Diyarbakır, Mardin, Şanlıurfa, Adıyaman, Gaziantep ve Kilis illerindeki farklı konukçulardan toplanan Aleyrodidae familyasına ait türler, pupa ve pupa kabuğunadan morfolojik tanı karakterleri kullanılarak Beyazsinek (Hemiptera: Aleyrodidae) türlerinin belirlenmesi amacıyla yapılmıştır. Çalışmada tarım, orman ve tarım dışı alanlardan örnekler toplanmıştır. Çalışma esnasında örnek toplama yılın tüm dönemlerinde düzensiz çıkışlar yapılarak gerçekleştirilmiştir. Toplanan örneklerden 9 beyazsinek türü tespit edilmiştir. Bu türler; Bemisia afer, B. tabaci, Dialeurodes citri, Dialeurolobus pulcher, D. rhamni, Massileurodes setiger, Siphoninus phillyreae, Trialeurodes vaporariroum ve Tetraleurodes neemani olarak tespit edilmiştir.

Studies on the predator Apertochrysa astur (Banks) (debris carrying green lacewing) on invasive coconut whiteflies

The invasive whitefly species, rugose spiralling whitefly (RSW) and Bondar’s nesting whitefly (BNW) (Hemiptera: Aleyrodidae) were reported on coconut in 2016 at Pollachi, Tamil Nadu, India and in 2019 in Kerala, India, respectively. Among the natural enemies of whiteflies, Apertochrysa astur (Banks) is the predominant predator observed in the coconut ecosystem. The population effect of RSW and BNW in different host plants, viz., coconut, banana and custard apple, on the growth and development of the A. astur were studied. Further, the effects of A. astur and yellow sticky traps (YSTs) were evaluated against the invasive whiteflies of coconut. The growth and development of the grubs of A. astur were better when fed with the RSW and BNW reared in coconut, followed by custard apple and banana. The weight of the 1st, 2nd and 3rd instar grubs were 0.25 mg, 0.62 mg and 2.46 mg, respectively. The pre-pupal weight was 7.41 mg, and that of the pupa and adult were 8.35 mg and 12.27 mg when fed with RSW. Similarly, when A. astur was fed with BNW reared on coconut, the weight of the 1st, 2nd and 3rd instar grub of A. astur was 0.22 mg, 0.59 mg and 2.24 mg, respectively. The pre-pupal weight was 7.06 mg, and that of the pupa and adult were 8.22 mg and 12.01 mg, respectively. Among the different treatment dosages of A. astur eggs and YSTs evaluated, 3 YST and 10 A. astur eggs palm-1 were highly effective as they reduced RSW and BNW population by 59.7 per cent and 56.7 per cent per cent, respectively. The grubs of A. astur were observed to be extremely efficient in reducing the population of A. rugioperculatus and P. bondari. The results supported that A. astur can be employed as an efficient biological control agent for managing invasive whitefly species in the coconut ecosystem.

First Report of an Alien Whitefly Predatory Beetle, Delphastus pallidus (LeConte) (Insecta: Coleoptera: Coccinellidae) from South Punjab, Pakistan

Delphastus pallidus (LeConte) is an important predatory beetle reported for effective control of whiteflies including Bemisia tabaci, Aleurotrachelus trachoides, Paraleyrodes bondari and Dialeurodes citrifolii. Many other members of genus Delphastus are well known predators of multiple whitefly species such as Delphastus catalinae (Horn). The members of this genus have predatory potential against all the stages of whitefly including eggs, nymphs and adults. This genus was reported in earlier 1950s from Florida on citrus whitefly. The later studies have reported it from Beach and the Mims areas in 1951, Indian Rocks Lake Alfred areas in 1953. It was not reported against cotton whitefly from anywhere of Pakistan. The Pest Warning Quality Control of Pesticides, Punjab team Multan reported it from cotton fields. Samples were collected and got identified from the Department of Entomology, Muhammad Nawaz Sharif University of Agriculture, Multan. After morphological and taxonomic identification, it was identified as Whitefly Predatory Beetle, Delphastus pallidus (LeConte) (Insecta: Coleoptera: Coccinellidae). Extensive surveys during the 3rd week of August 2022 reported its presence in 15 tehsils of cotton zone, South Punjab, Pakistan.

The Leaf Color and Trichome Density Influence the Whitefly Infestation in Different Cassava Cultivars.

The whitefly species Bemisia tuberculata and Aleurotrixus aepim (Hemiptera: Aleyrodidae) are considered important cassava (Manihot esculenta) pests. Leaf color and other morphological characteristics can influence the pest's interactions with the host plants. Thus, this study aimed to identify the relationship between whitefly occurrence and trichome density and leaf color in different cassava cultivars. The study was conducted in the field during the 2014/2015 and 2016/2017 crop seasons. The whitefly occurrence was surveyed in the cultivars, IAPAR 19, IPR Upira, IPR União, IAC 576-70, IAC 14, IAC 90, Catarina Branca, Santa Helena and Baianinha. The whitefly nymph quantification was correlated with non-glandular trichome density, luminosity (L*) and chroma (a* and b*) of the cassava leaves. IAPAR 19 and IAC 14 were less infested by whitefly nymphs when contrasted with IPR União, IPR Upira and Baianinha, which were the most infested. The lowest B. tuberculata infestations were correlated with lesser trichome density, highest light reflection and highest chroma in the sprout and the plant's superior third portion leaves. Low A. aepim infestation in both crop seasons made it impossible to verify its correlation with the studied cassava plant characteristics. The cultivars IAPAR 19 and IAC 14 could contribute towards B. tuberculata management in regions with a history of whitefly infestation.

Repellency, contact toxicity, and anti-oviposition effects of three ethanol-extracted plant essential oils on Bemisia tabaci (Hemiptera: Aleyrodidae).

There are more than 1200 species of whiteflies found across the globe. Due to the high level of resistance of whitefly against synthetic insecticides, alternate pest management measures have their significance. Plant essential oils (EOs) affect insect pests in many ways, such as via stimulatory, deterrent, toxic, and hormonal effects. This study was designed to determine the repellency of EOs, toxicity, and oviposition deterrent activities of Allium ascalonicum, Cinnamomum camphora, and Mentha haplocalyx against adult whiteflies. In repellency determination experiments, a single tomato plant was treated with 10ml of ethanol-extracted EO with 1000 ppm concentration. Results showed that C. camphora EO was the most repellent for whitefly compared to M. haplocalyx and A. ascalonicum. The oviposition deterrent experiments revealed that C. camphora has the highest oviposition deterrent effect, followed by M. haplocalyx and A. ascalonicum. A single plant treatment method was used to assess the contact toxicity of three EOs against whitefly after 12, 24, 48, and 72 h of exposure. The results revealed that C. camphora is more toxic to whitefly than M. haplocalyx and A. ascalonicum. After determining the antagonistic effects of these EOs, the oils were analyzed using gas chromatography/mass spectrometry to identify the chemical components. It can be concluded that C. camphora is the most effective oil EO in terms of toxicity, repellence, and oviposition deterrence, followed by M. haplocalyx and A. ascalonicum under greenhouse conditions. Our results introduce some new eco-friendly plant EOs to control whiteflies.

Genetic diversity of whitefly species of the Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) species complex, associated with vegetable crops in Côte d'Ivoire.

Since several years, whiteflies of the species complex of Bemisia tabaci (Gennadius) are causing several damages on vegetable crops in Côte d'Ivoire. These sap-sucking insects are the main vector of many viruses on tomato and several species of this complex have developed resistances against insecticides. Nevertheless, there is very little information about whitefly species on vegetable crops in Côte d'Ivoire. Here, we investigated the species diversity and their genetic diversity and structuring on samples from vegetable crops in the major tomato production areas of Côte d'Ivoire. To assess this diversity, 535 whitefly samples from different localities and plant species were collected and analysed with nuclear (microsatellite) and mitochondrial (mtCOI) markers. In each site, and ecological data were recorded, including whiteflies abundance and plant species colonised by B. tabaci. The analysis of mtCOI sequences of whiteflies indicated the presence of four cryptic species on tomato and associated crops in Côte d'Ivoire. These were MED ASL, MED Q1, SSA 1 and SSA3. The MED ASL species dominated over all samples in the different regions and plant species. One haplotype of MED ASL out of the 15 identified predominated on most plant species and most sites. These results suggested that MED ASL is probably the main phytovirus vector in the Ivorian vegetable cropping areas. In contrast, only five haplotypes of MED Q1 were identified on vegetables but in the cotton-growing areas of the country. Its low prevalence, low nuclear and mitochondrial diversity might indicate a recent invasion of this species on vegetable crops in Côte d'Ivoire. The Bayesian nuclear analysis indicated the presence of hybrid genotypes between the two main species MED ASL and MED Q1, however in low prevalence (10%). All these results highlight the need to maintain whitefly populations monitoring for a more effective management in Côte d'Ivoire.

Integrated Potential of Microbial, Botanical, and Chemical Pesticides for the Control of Viral Disease Vector Whiteflies (Hemiptera: Aleyrodidae) on Tomato under Greenhouse and Field Perspectives

Whiteflies are one of the most devastating horticultural pests attacking tomatoes. Although there are several control methods for the control of whitefly pests, the integrated application of entomopathogenic fungi (IPM) with chemical and botanical insecticides has proven more effective than individual control agents. This study was carried out to evaluate individual and combined treatments of entomopathogens B. bassiana, M. anisopliae, B. thuringiensis, Hunter 40 EC, and neem oil for the control of whitefly species on tomato (Solanum lycopersicum) under greenhouse and field condition. The greenhouse study showed that the different treatments resulted in a 58.48 to 100% reduction of nymphs and a 52.06 to 100% reduction of adults on both Galilea and Melkashola tomato varieties under greenhouse conditions. The combined treatments of AAUMB-29 + Neem oil displayed a higher yield (423.3 g fruits/plant) on the Gelilea tomato variety, and AAUDM-43 + Hunter 40 EC displayed a yield of (376.66 g/plant) on the Melkashola tomato variety. Under field conditions, the application of AAUMB-29 + Hunter 40 EC + Neem oil significantly decreased the whitefly population by 91.93% (P<0.001) after 10 days of the fourth spray. The result of fruit yield of tomato was significantly higher in all treatments (31.17 t to 70.42 t·ha−1) compared to untreated control (25.83 t·ha−1). Among the treatments, AAUMB-29 + Hunter 40 EC + Neem oil gave the highest fruit yield of 70.42 t·ha−1 followed by AAUMB-29 + Hunter 40 EC (64.50 t·ha−1) on the Galilea tomato variety under field conditions. The combined treatment of AAUMB-29 + Hunter 40 EC + Neem oil was the most effective with lower whitefly infestation, higher marketable yields, and less percentage of yield losses. Further investigations are required to determine the optimization and practicability of this integrated application of treatments for the control of both sucking and chewing insect pests under field conditions.

Elucidating the sweet potato virome in Greece with the aid of high‐throughput sequencing technology

AbstractIn 2018, typical symptoms of sweet potato virus disease (SPVD) such as purple ringspots, distortion and crinkling of the leaves appeared on a sweet potato crop located in southern Greece. High‐throughput sequencing (HTS) analysis revealed the presence of seven viruses, sweet potato feathery mottle virus (SPFMV), sweet potato chlorotic stunt virus (SPCSV), sweet potato virus C (SPVC), sweet potato virus G (SPVG), sweet potato virus 2 (SPV2), sweet potato leaf curl virus (SPLCV) and sweet potato pakakuy virus (SPPV). In silico analysis of the HTS data in combination with Sanger sequencing succeeded in obtaining the complete genome sequences of all seven viruses. Nucleotide sequence comparisons of complete viral genomes showed high similarity of all detected potyviruses and SPLCV with homologous sequences retrieved from GenΒank, whereas a new variant of SPCSV RNA1 was characterized and successfully transmitted onto Nicotiana benthamiana plants with the whitefly species Bemisia tabaci MED and MEAM1. Moreover, the Greek strain of SPPV showed higher similarity with SPPV strain B, even though it possesses a variable RT‐RNase H domain. Further phylogenetic analysis clustered Greek sweet potato virus isolates into various phylogenetic groups, whereas few new clades were formed in the cases of SPFMV, SPVG and SPCSV RNA1. Small‐scale surveys on three different sweet potato crops exhibiting typical, mild or no symptoms also indicated the close association of SPCSV with SPVD. Taken together, this study characterizes for the first time the virome of sweet potato crops in Greece and provides a glimpse into the evolutionary relationships of the identified viruses.

Companion plants for conservative management of Tupiocoris cucurbitaceus (Spinola 1852) (Heteroptera: Miridae: Dicyphini) on greenhouse tomato crops

In recent decades, greenhouse crops relevance increased due to the high demand for products outside their growing season, with tomato standing out as one of the most cultivated crops. In these production systems, insects and mites find optimal conditions for their development, achieving high populations that affect crops. Farmers usually control these populations using chemical insecticides, which affect the health of workers and consumers and have negative effects on the environment. Tomato crops suffer damage by lepidopterans and hemipterans, among which those known as whiteflies (Hemiptera: Aleyrodidae) perform regular attacks, causing yield and quality losses in the final product. Currently, the use of zoophytophagous predators of the Miridae family, Dicyphini tribe, as an alternative for their biological control, has intensified studies on Tupiocoris cucurbitaceus (Spinola, 1852), a predator of several species of aphids and whiteflies found in Uruguay. A strategy for the conservative management of those species was designed, using companion plants grown together with the crop. By the time the tomato plants were transplanted, Calendula officinalis, Smallanthus connatus, Tithonia rotundifolia, Nicotiana tabacum, Physalis peruviana and Petunia hybrida plants were established as companion species. These plants were monitored weekly together with the tomato plants, and a greater presence of T. cucurbitaceus in the crops with companion plants was found. The results suggest that the incorporated plants were useful for the preservation and retention of predaceous mirids in productive conditions.

New records of whiteflies (Hemiptera, Aleyrodidae) and their host plants from Colombia

More than half of whiteflies (Aleyrodidae) species are distributed in the tropics. In Colombia, the taxonomic survey of this group has been neglected for almost three decades. This situation causes limitations in the study of basic and applied entomology for these sap-sucking insects, which are of considerable importance in agriculture as they affect an extensive number of cultivated and wild plants. In this work, we provide six species new records for the country, whose distribution is depicted in maps. Lastly, we mention the identification of the corresponding host plants.