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Viruses and viroids prevalent in a population of 42 wild grapevines (i.e., free-living, uncultivated grapevines; Vitis spp.) were compared with those in a population of 85 cultivated grapevines collected in Tennessee, United States by RNA sequencing analysis of pools of ribosomal RNA-depleted total RNA. The sequences of 10 viruses (grapevine fleck virus, grapevine leafroll-associated virus 2, grapevine rupestris stem pitting-associated virus, grapevine Syrah virus 1, grapevine vein-clearing virus, grapevine virus B, grapevine virus E, tobacco ringspot virus, tomato ringspot virus, and a novel nano-like virus) and two viroids (hop stunt viroid and grapevine yellow speckle viroid 1) were detected in both grapevine populations. Sequences of four viruses (grapevine associated tymo-like virus, grapevine leafroll-associated virus 3, grapevine red blotch virus, and grapevine virus H) were identified only from cultivated grapevines. High, moderate, and low numbers of sequence reads were identified only from wild grapevines for a novel caulimovirus, an enamovirus, and alfalfa mosaic virus, respectively. The presence of most virus sequences and both viroids was verified independently in the original samples by reverse-transcription PCR followed by Sanger sequencing. Comparison of viral sequences shared by both populations showed that cultivated and wild grapevines harbored distinct sequence variants, which suggests that there was limited virus movement between the two populations. Collectively, this study represents the first unbiased survey of viruses and viroids in both cultivated and wild grapevines within a defined geographic region.

Anticarsia gemmatalis Hünber, 1818 is one of the main defoliating species in the soybean crop. Bacillus thuringiensis Berliner, 1915, is a bacterium used in the biological control of this pest species. Resistant populations and their sublethal effects caused by the use of the bacteria have already been reported; however, there are no studies on phenotypic plasticity in adulthood exposed to Bt-based bioinsecticide sub-doses. This study aimed to evaluate the morphometry of A. gemmatalis adults under laboratory conditions submitted to the Bt-based bioinsecticide Dipel SC over the three generations. The body segments mensuread were width, length, and area of the anterior and posterior wings, the weight of the integument, chest, abdomen, wings, and the whole adult of males and females. Among the treatments, LC5 in the first generation and CL10 in the second generation were those with lower thresholds in relation to the weight of the chest and abdomen, considering the proportions of the body smaller than the females. The female’s weight adulthood was reduced by 10% about males, and, only in the first generation. Males have larger body size and more pronounced phenotypic plasticity than females. Here, we demonstrate the first study assessing the phenotypic plasticity of A. gemmatalis adults.

Insecticidal gene silencing by RNA interference (RNAi) involves a post-transcriptional mechanism with great potential for insect control. Here, we aim to summarize the progress on RNAi research toward control of insect pests in the Neotropical region and discuss factors determining its efficacy and prospects for pest management. We include an overview of the available RNAi information for Neotropical pests in the Lepidoptera, Coleoptera, Diptera, and Hemiptera orders. Emphasis is put on significant findings in the use of RNAi against relevant Neotropical pests, including diamondback moth (Plutella xylostella L.), Asian citrus psyllid (Diaphorina citri Kuwayama), and the cotton boll weevil (Anthonomus grandis Boheman). We also examine the main factors involved in insecticidal RNAi efficiency and major advances to improve screening of lethal genes, formulation, and delivery. Few studies detail resistance mechanisms to RNAi, demonstrating a need for more research. Advances in formulation, delivery, and resistance management tools for insecticidal RNAi in the Neotropics can provide a basis for efficient field application.

Bactrocera oleae (Rossi, 1790) (Diptera: Tephritidae) is monophagous and one of the primary plagues of the olive tree (Olea europaea L. (Lamiales: Oleaceae)), causing economic losses worldwide. The pest has been detected in the United States and Mexico, showing potential to invade new areas. Among the parasitoids used to control B. oleae, Fopius arisanus (Sonan, 1932) and Psyttalia concolor (Szepligeti, 1910) (Hymenoptera: Braconidae) are considered cenobiont and sinovigene endoparasitoids. Through the study of the potential geographic distributions, the size of regions environmentally suitable for the species can be understood, and the areas of distribution of the pest can be related with those of the parasitoids, with the goal to estimate whether the parasitoids would be suitable for use in classic biological control. The aim of this study was to map the potential global distribution regions, with an emphasis on South America, of B. oleae and the two parasitoids F. arisanus and P. concolor and show the overlap of geographically environmentally adequate areas for the joint establishment of the pest and natural enemy. For map the potential global distribution regions, a predictive model correlative of the distribution of the species was used, generated from known data of the localities of occurrence of insects and environmental predictor variables. The algorithm chosen for the modeling was Max Entropy (MaxEnt). The evaluation of the model was based on the mean Area Under the Curve (AUC), which was 0.966, 0.982 and 0.995 for B. oleae, F. arisanus, and P. concolor, respectively, indicating good predictive performance of the models and reliable projections. In general, the most significant extent of the potential distribution of F. arisanus was observed in Asia (most likely because it is the region of origin), Central America and South America. In Africa and North America, F. arisanus was also the most comprehensively distributed, in general; however, in the regions related to the occurrence of B. oleae and olive cultivation, P. concolor presented a greater potential distribution than that of F. arisanus. In Europe and Oceania, P. concolor had potential distribution projected in areas with olive groves.

Made available in DSpace on 2022-05-01T09:30:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Bioinsecticides based on Bacillus thuringiensis (Bt) Berliner, 1915 are widely used to control lepidopteran in several crops. However, surviving insects exposed to the sub-lethal concentration of Bt-based bioinsecticides can suffer a multitude of effects on the biological conditioning known as hormesis. Here, we aimed to provide a clearer understanding of the biological conditioning of Anticarsia gemmatalis (Hübner, 1818), exposed to different concentrations of a Bt-based bioinsecticide, by assessing life table parameters over three generations. We defined five sub-lethal concentrations (LC5, LC10, LC15, LC20, and LC25) from the response curve estimate of A. gemmatalis. Deionized water was used as a control. We assessed the parameters of eggs-viability and the duration of the stages, incubation, larval, pre-pupal, pupal, adult, pre-oviposition and total biological cycle. Data were used to construct the fertility life table using the two-sex program. The survival curves showed greater variation in the proportion of individuals at each development stage using the LC25. The sub-lethal concentrations did not influence the incubation-eggs period, pre-pupal and pupal. However, the larval and adult stages using LC25 and LC10 were the most affected. Changes in sex ratio were observed using LC20 and LC5. The toxic effect of Bt-based bioinsecticide interfered mainly in the parameters of fertility, sex ratio, net reproduction rate (R0), and gross reproduction rate (GRR). Department of Plant Protection Paulista State University “Júlio de Mesquita Filho” Department of Biological and Health Sciences Faculty of Philosophy Sciences and Letters of Ribeirão Preto University of São Paulo Department of Entomology and Plant Pathology University of Tennessee Department of Biology Applied to Agriculture Paulista State University “Júlio de Mesquita Filho” Department of Plant Protection Paulista State University “Júlio de Mesquita Filho” Department of Biology Applied to Agriculture Paulista State University “Júlio de Mesquita Filho”

Over the past few years, the use of RNA interference (RNAi) for insect pest management has attracted considerable interest in academia and industry as a pest-specific and environment-friendly strategy for pest control. For the success of this technique, the presence of core RNAi genes and a functional silencing machinery is essential. Therefore, the aim of this study was to test whether the Neotropical brown stinkbug Euschistus heros has the main RNAi core genes and whether the supply of dsRNA could generate an efficient gene silencing response. To do this, total mRNA of all developmental stages was sequenced on an Illumina platform, followed by a de novo assembly, gene annotation and RNAi-related gene identification. Once RNAi-related genes were identified, nuclease activities in hemolymph were investigated through an ex vivo assay. To test the functionality of the siRNA machinery, E. heros adults were microinjected with ~28 ng per mg of insect of a dsRNA targeting the V-ATPase-A gene. Mortality, relative transcript levels of V-ATPase-A, and the expression of the genes involved in the siRNA machinery, Dicer-2 (DCR-2) and Argonaute 2 (AGO-2), were analyzed. Transcriptome sequencing generated more than 126 million sequenced reads, and these were annotated in approximately 80,000 contigs. The search of RNAi-related genes resulted in 47 genes involved in the three major RNAi pathways, with the absence of sid-like homologous. Although ex vivo incubation of dsRNA in E. heros hemolymph showed rapid degradation, there was 35% mortality at 4 days after treatment and a significant reduction in V-ATPase-A gene expression. These results indicated that although sid-like genes are lacking, the dsRNA uptake mechanism was very efficient. Also, 2-fold and 4-fold overexpression of DCR-2 and AGO-2, respectively, after dsRNA supply indicated the activation of the siRNA machinery. Consequently, E. heros has proven to be sensitive to RNAi upon injection of dsRNA into its hemocoel. We believe that this finding together with a publically available transcriptome and the validation of a responsive RNAi machinery provide a starting point for future field applications against one of the most important soybean pests in South America.

Several fruit fly species are invasive pests that damage quality fruits in horticultural crops and cause significant value losses. The management of fruit flies is challenging due to their biology, adaptation to various regions and wide range of hosts. We assessed the historical and current approaches of fruit fly management research worldwide, and we established the current knowledge of fruit flies by systematically reviewing research on monitoring and control tactics, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We performed a systematic review of research outputs from 1952 to 2017, by developing an a priori defined set of criteria for subsequent replication of the review process. This review showed 4900 publications, of which 533 publications matched the criteria. The selected research studies were conducted in 41 countries for 43 fruit fly species of economic importance. Although 46% of the studies were from countries of North America, analysis of the control tactics and studied species showed a wide geographical distribution. Biological control was the most commonly studied control tactic (29%), followed by chemical control (20%), behavioral control, including SIT (18%), and quarantine treatments (17%). Studies on fruit flies continue to be published and provide useful knowledge in the areas of monitoring and control tactics. The limitations and prospects for fruit fly management were analyzed, and we highlight recommendations that will improve future studies.

Biopesticides based on the entomopathogenic bacteria Bacillus thuringiensis (Bt) are used worldwide on broad-extensions of different crops and vegetables, mainly against lepidopteran and coleopteran pests. The first attempts to use this microbial control agent as biopesticide date from 1938, but it was until 1970s that some quality constraints on the formulations were solved, and right now, multiple formulations are available in the market and are used in the field. The high selectivity of Bt pesticidal proteins, without harming natural enemies and non-target organisms, is the main factor involved in their reduced environmental risk, in contrast with the broad-spectrum chemical pesticides. Moreover, the high efficacy of Bt biopesticides has already played a significant role in suppressing some pests' outbreaks. Nevertheless, despite the improvements of Bt formulations over the past 50 years, abiotic factors such as temperature, ultraviolet radiation, rainfall, and other factors such as farmer practices are still considered the main obstacles to the broader adoption of Bt biopesticides. Here, we discuss the challenges of Bt biopesticides and the perspectives to improve their adoption, including tank mixtures, technology application, formulations, and insect resistance.

O Rio Grande do Sul é o principal estado produtor e armazenador de arroz do Brasil, com destaque para a região Fronteira Oeste. Objetivou-se, com este trabalho, detectar os pontos críticos para a ocorrência de insetos em duas unidades armazenadoras de arroz no município de Itaqui, Fronteira Oeste do Rio Grande do Sul. Foram realizadas inspeções visuais em duas unidades armazenadoras durante o recebimento da safra 2010/2011 e estabelecidos os critérios de presença de insetos adultos e o acúmulo de impurezas, resíduos de grãos e poeira. Foram inspecionados: o pátio de estacionamento externo e interno, balanças, moegas de descarga, área de secagem, adjacências dos silos armazenadores, indústria de beneficiamento, unidades armazenadoras de produto finalizado, laboratório e classificação, elevadores e túneis. Os resultados apontaram como pontos críticos para ocorrência de pragas, o pátio de estacionamento externo e interno, a balança, as moegas de descarga, a área de secagem, as adjacências de silos, os pés de elevadores, as esteiras transportadoras e os túneis da indústria de beneficiamento. O acúmulo de poeira e os resíduos são os principais responsáveis pelos pontos críticos.

Fruit flies (Diptera: Tephritidae) are considered to be one of the principal groups of pests in fruit culture worldwide. The objective of this study was to investigate oviposition by Anastrepha fraterculus (Wiedemann) and Ceratitis capitata (Wiedemann) in citrus fruits and to assess the development of these species in relation to the maturity of orange fruits. The experiments were carried out under controlled temperature conditions (25 ± 2 °C), RH (70 ± 10%), and photoperiod (12:12 h L:D). Oviposition was evaluated by exposure (with and without choice) to fruits of ‘Navelina’orange [Citrus sinensis (L.) Osbeck], ‘Clemenules’ tangerine (C. reticulata Blanco), and ‘Siciliano’ lemon [C. limon (L.)] (Rutaceae). Insect development was studied on Navelina orange at 4 stages of maturity (I: 5 cm in diameter, II: 6 to 7 cm in diameter, III: skin with color change, and IV: yellow-orange skin). We evaluated oviposition by counting the number of eggs, and we assessed biological parameters of the immature and adult stages. The number of eggs deposited in orange and tangerine by both fruit fly species did not differ significantly, and oviposition did not occur in lemon. Anastrepha fraterculus preferred to oviposit in tangerine fruits, whereas C. capitata showed preference for orange fruits. Development from egg to adult by A. fraterculus and C. capitata occurred only in stage IV oranges, and required 30.9 and 31.0 d, respectively. Females of A. fraterculus and C. capitata developing in mature orange fruits produced a mean of 378.7 and 183.5 eggs, respectively.

Since the discovery of RNA interference (RNAi), scientists have made significant progress towards the development of this unique technology for crop protection. The RNAi mechanism works at the mRNA level by exploiting a sequence-dependent mode of action with high target specificity due to the design of complementary dsRNA molecules, allowing growers to target pests more precisely compared to conventional agrochemicals. The delivery of RNAi through transgenic plants is now a reality with some products currently in the market. Conversely, it is also expected that more RNA-based products reach the market as non-transformative alternatives. For instance, topically applied dsRNA/siRNA (SIGS – Spray Induced Gene Silencing) has attracted attention due to its feasibility and low cost compared to transgenic plants. Once on the leaf surface, dsRNAs can move directly to target pest cells (e.g., insects or pathogens) or can be taken up indirectly by plant cells to then be transferred into the pest cells. Water-soluble formulations containing pesticidal dsRNA provide alternatives, especially in some cases where plant transformation is not possible or takes years and cost millions to be developed (e.g., perennial crops). The ever-growing understanding of the RNAi mechanism and its limitations has allowed scientists to develop non-transgenic approaches such as trunk injection, soaking, and irrigation. While the technology has been considered promising for pest management, some issues such as RNAi efficiency, dsRNA degradation, environmental risk assessments, and resistance evolution still need to be addressed. Here, our main goal is to review some possible strategies for non-transgenic delivery systems, addressing important issues related to the use of this technology.

RNA interference (RNAi) technology has been used in the development of approaches for pest control. The presence of some essential genes, the so-called “core genes,” in the RNAi machinery is crucial for its efficiency and robust response in gene silencing. Thus, our study was designed to examine whether the RNAi machinery is functional in the South American (SA) fruit fly Anastrepha fraterculus (Diptera: Tephritidae) and whether the sensitivity to the uptake of double-stranded RNA (dsRNA) could generate an RNAi response in this fruit fly species. To prepare a transcriptome database of the SA fruit fly, total RNA was extracted from all the life stages for later cDNA synthesis and Illumina sequencing. After the de novo transcriptome assembly and gene annotation, the transcriptome was screened for RNAi pathway genes, as well as the duplication or loss of genes and novel target genes to dsRNA delivery bioassays. The dsRNA delivery assay by soaking was performed in larvae to evaluate the gene-silencing of V-ATPase, and the upregulation of Dicer-2 and Argonaute-2 after dsRNA delivery was analyzed to verify the activation of siRNAi machinery. We tested the stability of dsRNA using dsGFP with an in vitro incubation of larvae body fluid (hemolymph). We identified 55 genes related to the RNAi machinery with duplication and loss for some genes and selected 143 different target genes related to biological processes involved in post-embryonic growth/development and reproduction of A. fraterculus. Larvae soaked in dsRNA (dsV-ATPase) solution showed a strong knockdown of V-ATPase after 48 h, and the expression of Dicer-2 and Argonaute-2 responded with an increase upon the exposure to dsRNA. Our data demonstrated the existence of a functional RNAi machinery in the SA fruit fly, and we present an easy and robust physiological bioassay with the larval stages that can further be used for screening of target genes at in vivo organisms’ level for RNAi-based control of fruit fly pests. This is the first study that provides evidence of a functional siRNA machinery in the SA fruit fly.

Made available in DSpace on 2020-12-12T02:27:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-11-01 Bacillus thuringiensis (Bt) biopesticides are an environmentally safe alternative to the management of Plutella xylostella pesticide resistance evolution. We evaluated P. xylostella susceptibility to six Bt strains cultivated and applied individually, and 15 combinations of Bt strains mixed after cultivation. Three combinations resulted in synergism and one in antagonism. Promising results of larval mortality with synergistic effects were obtained with the combinations Bt var. thuringiensis strain HD-2 + Bt finitimus strain HD-3, Bt var. thuringiensis strain HD-2 + Bt dendrolimus strain HD-7 and Bt var. thuringiensis strain HD-2 + Bt var. aizawai strain HD-11. Federal Institute Goiano-Campus Morrinhos (IFGOIANO), Morrinhos São Paulo State University “Júlio de Mesquita Filho” (UNESP/FCAV), Jaboticabal São Paulo State University “Júlio de Mesquita Filho” (UNESP/FCAV), Jaboticabal

Fruit flies (Diptera: Tephritidae) represent a threat to fruit growing worldwide, mainly the citrus culture, however, biological studies show that fruit flies are not perfectly adapted to this host. This study investigated oviposition of Anastrepha fraterculus (Wiedemann, 1830) and Ceratitis capitata (Wiedemann, 1824) and its relation with the pericarp of citrus fruits. We evaluated the relationship between depth of oviposition of A. fraterculus and C. capitata and epicarp thickness of orange [Citrus sinensis (L.) Osbeck)] ‘Navelina’ and tangerine [C. reticulata (L.)] ‘Clemenules’ and the influence of fruit mesocarp of tangerine ‘Clemenules’ on oviposition of these species. The study was conducted under controlled conditions of temperature (25 ± 2 °C), relative humidity (70 ± 10% RH) and photophase (12 h). A. fraterculus and C. capitata laid their eggs in the flavedo region of orange ‘Navelina’ and between the albedo and flavedo of tangerine ‘Clemenules’. When fruits with mesocarp exposed were offered, there was no oviposition by both fruit fly species. The results show that epicarp thickness of citrus fruits did not influence oviposition of A. fraterculus and C. capitata as oviposition did not occur only in the presence of the mesocarp, suggesting that other factors are involved in oviposition of these species. Resumo As moscas-das-frutas (Diptera: Tephritidae) representam um risco à fruticultura mundial, especialmente na cultura dos citros, entretanto estudos biológicos demonstram que as moscas-das-frutas não estão perfeitamente adaptadas à estes hospedeiros. Este estudo investigou a oviposição de Anastrepha fraterculus (Wiedemann, 1830) e Ceratitis capitata (Wiedemann, 1824) e sua relação com o pericarpo de frutos cítricos. Foi avaliada a relação entre a profundidade de oviposição de A. fraterculus e de C. capitata e a espessura do epicarpo dos frutos de laranjeira [Citrus sinensis (L.) Osbeck)] ‘Navelina’ e tangerineira [C. reticulata (L.)] ‘Clemenules’ e a influência do mesocarpo de frutos de tangerineira ‘Clemenules’ na oviposição destas espécies. O estudo foi conduzido em condições controladas de temperatura (25 ± 2 °C), umidade relativa (70 ± 10%) e fotofase (12 horas). A. fraterculus e C. capitata depositaram ovos no flavedo de frutos de laranjeira ‘Navelina’ e entre o flavedo e o albedo de frutos de tangerineira ‘Clemenules’. Quando oferecido frutos com mesocarpo exposto, não houve oviposição por ambas as espécies de mosca. Os resultados demonstram que a espessura do epicarpo de frutos cítricos não influenciou a oviposição de A. fraterculus e de C. capitata, a qual não ocorreu na presença apenas do mesocarpo, sugerindo que outros fatores estão envolvidos na oviposição por estas espécies.

Fruit flies (Diptera: Tephritidae) are considered the main fruit pests worldwide. In Brazil, two species are predominant: the South American fruit fly, Anastrepha fraterculus and the Mediterranean fruit fly, Ceratitis capitata. In this study, we evaluated the effect of artificial diets with variable pH in their larval development and adult performance. The experiments were carried out in the laboratory at 25 ± 2 °C, 70 ± 10% RH and 12:12h (L:D) photoperiod. Semisolid diets with pH values of 6.0, 5.0, 4.0, 3.0, 2.0, 1.5, and 1.0, adjusted by adding hydrochloric acid were tested. Results indicated that the diet with pH 6.0 did not support larval development of both species of fruit fly. Diets with greater acidic pH values did not allow egg, larvae or pupae development and adult reproduction of A. fraterculus. For C. capitata , the pH of artificial diet exerts greater influence compared to A. fraterculus on the duration and viability of the larval stage, number of pupae, sex ratio and longevity of males. Resumo As moscas-das-frutas (Diptera: Tephritidae) são consideradas as principais pragas da fruticultura mundial. No Brasil, duas espécies são predomindantes: a mosca-das-frutas Sul-americana, Anastrepha fraterculus e a mosca-do-Mediterrâneo, Ceratitis capitata. Neste estudo avaliamos o efeito de dietas artificiais com pH variável no seu desenvolvimento larval e performance de adultos. Os experimentos foram realizados em laboratório a 25 ± 2 °C, 70 ± 10% UR e fotoperíodo de 12:12 horas. Foram testadas dietas semi-sólidas com valores de pH de 6,0; 5,0; 4,0; 3,0; 2,0; 1,5 e 1,0, ajustados pela adição de ácido clorídrico. Os resultados indicaram que a dieta com pH 6,0 não suportou o desenvolvimento larval de ambas as espécies de mosca-das-frutas. As dietas com pH ácido não permitiram o desenvolvimento de ovos, larvas ou pupas e a reprodução de adultos de A. fraterculus. Para C. capitata o pH da dieta artificial exerceu maior influência do que para A. fraterculus nos parâmetros de duração e viabilidade do estágio larval, número de pupas, razão sexual e longevidade de machos.

The fruit -flies ( Diptera : Tephritidae Lonchaeidae ) represent a major pest problems in fruit production , but in the state of Rio Grande do Sul, the information about these pests are scarce in the literature. The aim of this work was to verify the occurrence of fruit -flies in four districts of West Frontier of Rio Grande do Sul collections fruits were held in rural and urban areas in the municipalities of Itaqui Quarai , Santana of Deliverance Uruguayana and during the years 2011 and 2012 . The fruits after heavy and quantified , were transferred to trays containing a layer of sand to obtain the pupae . Altogether , 5,384 fruits ( 315.64 kg ) were collected in the four sampled counties . 3,088 copies of fruit flies infesting 4,961 ( 231.79 kg ) in 14 of 19 sampled plant species were obtained . Of these , 2,968 copies were Ceratitis capitata ( Wiedemann ) and Anastrepha fraterculus 98 ( Wiedemann ) . Other flies , such as lonchaeids represented only 22 specimens of the total obtained by bringing the first host record for Neosilba zadolicha ( McAlpine and Steyskal ) in the region . It was found that C. capitata is the predominant species in the border region of Rio Grande do Sul

Made available in DSpace on 2020-03-05T00:36:44Z (GMT). No. of bitstreams: 1 DoriteseNaymarevisada.pdf: 1755430 bytes, checksum: c9a3490d8627ae9b74387bf48f449cb2 (MD5) Previous issue date: 2019 Tese (Doutorado) - Programa de Pós-Graduação em Fitossanidade. Universidade Federal de Pelotas, Pelotas. Orientador: Dori Edson Nava, Co-orientador: Moisés João Zotti, Guy Smagghe.

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