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This study aimed to determine the repellent and insecticidal activity of four essential oils (EOs) from plants collected in the Chocó rain forest, Colombia, against T. castaneum . Conventional hydrodistillation was used to obtain the EOs. The repellent and insecticidal activities were evaluated by the preference area and gas dispersion methods, espectively. Statistical differences (p<0.05) were determined by applying a student's t-test. EOs of Siparuna guianensis, S. conica, Piper marginatum, and Nectandra acutifolia showed excellent repellent properties as the main findings, highlighting S. conicaEO with 84% repellency (1-hµL/cm2), while P. marginatum showed to be bioactive to the dose of 500 µL/mL (72 h), inducing mortality of 100% of the exposed population. In conclusion, the results evidenced the repellent properties of the EOs evaluated against T. castaneum , which allows us to conclude that these plant species are potential natural sources producing bio-repellents that contribute to the integrated control of T. castaneum.

Se evaluaron cuatro aceites esenciales (AEs) de plantas recolectadas en la selva pluvial del Chocó, Colombia, para determinar su actividad repelente e insecticida contra T. castaneum. Los AEs fueron obtenidos por hidrodestilación convencional. Las actividades repelentes e insecticidas se evaluaron por los métodos de área de preferencia y dispersión de gas, respectivamente. Las diferencias significativas (p<0,05) fueron determinadas aplicando una prueba t de student. Los AEs de Siparuna guianensis, S. conica, Piper marginatum y Nectandra acutifolia mostraron excelentes propiedades repelentes, destacando el AE de S. conicacon un 84% de repelencia (1µL/cm2), mientras que el AE de P. marginatummostró ser bioactivo a la dosis de 500 µL/mL (72 h) al inducir la mortalidad del 100% de la población expuesta. Se concluye que estas especies de plantas son fuentes naturales potencialmente viables para la producción de biorepelentes que contribuyan en el control integrado de T. castaneum.

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The soybean bud borer, a soybean pest in Brazil, was initially identified as Crocidosema aporema (Walsingham 1914) (Lepidoptera: Tortricidae). Outbreaks of this species have recently increased, but identification of this pest remains uncertain, and the historical factors associated with its geographic distribution in Brazil are little known. Here, we conducted a species characterization and phylogeographic analysis based on molecular and morphological evidence. Ninety individuals of bud-borers Lepidoptera were collected in different regions of Brazil. We sequenced COI and COII mitochondrial genes and examined wing patterns and male genital morphology. DNA barcoding approach revealed that 10 individuals were Argyrotaenia sphaleropa (Meyrick 1909) (Lepidoptera: Tortricidae) and 80 were a species of the genus Crocidosema Zeller. The morphology of the adult genitalia and wings proved to be insufficient to confirm the identification of Brazilian individuals as C. aporema, a species originally described from a high-elevation site in Costa Rica. Furthermore, the genetic distance between putative C. aporema specimens from Brazil and Costa Rica (ranging from 5.2% to 6.4%) supports the hypothesis that the Brazilian specimens are not referable to C. aporema. Our analysis revealed a single genetic strain (i.e., species) with low genetic diversity on soybean crops. We found no indication that the genetic structure was related to geographic distance among populations or edaphoclimatic regions. The population expansion of the soybean bud borer coincides with the increase in the area of soybean production in Brazil, suggesting that expanded soybean farming has allowed a significant increase in the effective population size of this pest.

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The application of the sterile insect technique (SIT) requires the adaptation of insects to mass-rearing conditions. It is generally accepted that this adaptation may include a reduction in genetic diversity and an associated loss of desirable characteristics for the effective performance of sterile insects in the field. Here, we compare the genetic diversity of two mass-reared strains of the Mexican fruit fly, Anastrepha ludens, and a wild (WIL) population collected near Tapachula, Mexico, using seven DNA microsatellites as molecular genetic markers. The mass-reared strains were a bisexual laboratory strain (LAB) with approximately 130 generations under mass-rearing and a genetic sexing strain, Tapachula-7 (TA7), also under mass-rearing for 100 generations. Our results revealed an overall low level of genetic differentiation (approximately 15%) among the three strains, with the LAB and WIL populations being genetically most similar and TA7 most genetically differentiated. Although there were some differences in allele frequencies between strains, our results show that overall, the adaptation to mass-rearing conditions did not reduce genetic variability compared to the wild sample in terms of heterozygosity or allelic richness, nor did it appear to alter the level of inbreeding with respect to the wild populations. These results are contrary to the general idea that mass-rearing always results in a reduction in genetic diversity. Overall, our findings can contribute to a better understanding of the impact that adaptation to mass-rearing conditions may have on the genetic make-up of strains.

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BACKGROUND: Temperature plays a critical role in the development and reproductive process of insects, therefore understanding how insects respond to temperature is vital for comprehending and predicting their population dynamics, particularly when it comes to agricultural pests. Spodoptera eridania Stoll is a polyphagous pest that has recently expanded its distribution beyond its native range. In this study, we assessed the impact of temperature on the reproduction of S. eridania and used the obtained data to develop an oviposition model that could be used to predict egg-laying behavior under field conditions. The reproductive parameters were evaluated at temperatures of 15, 20, 25, 28, and 32 °C. RESULTS: Temperature had a significant impact on the reproductive parameters examined. Overall, as temperature increased, the pre-oviposition period, oviposition period, and longevity decreased. Total fecundity exhibited a bell-shaped response to temperature, with peak egg-laying observed at 20 and 25 °C. In line with the experimental data, our model predicted higher rates of oviposition between 20 and 26 °C, thus reinforcing that this temperature range may represent the optimal conditions for the reproduction of S. eridania. CONCLUSION: The findings from our study provide a significant contribution to the understanding of the ecology of an important agricultural pest. The information generated can have practical applications in developing control strategies by enabling the aligning of the timing of control measures with peaks of reproductive activity. © 2023 Society of Chemical Industry.

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RESUMEN El palto es un cultivo muy importante, a nivel mundial y en Perú, siendo una plaga importante el ácaro Oligonychus punicae. El presente trabajo tuvo como objetivo determinar el efecto de diferentes niveles poblaciones del O. punicae, en el contenido de clorofila en hojas de palto y su impacto en su rendimiento e inferir un umbral económico y de intervención. Se utilizó un diseño completamente al azar, considerando 3 tratamientos con diferentes niveles poblacionales, correspondiente a los grados 2, 3 y mayor que 3. Se tomó un árbol como unidad experimental con 20 repeticiones por tratamiento, en donde se evaluó la población de ácaro en 4 hojas por árbol. Estas evaluaciones se realizaron con frecuencia semanal durante toda la campaña. Se midió el contenido de clorofila de las 4 hojas por árbol en cada tratamiento; asimismo, se evaluó el rendimiento en cada tratamiento (t ha-1). Los resultados mostraron que los diferentes grados de infestación estudiados: Grado 2 (1-10 ácaros/hoja), Grado 3 (11-25 ácaro/hoja), Grado 4 (26-50 ácaros/hoja) y Grado 5 (mayor a 50 ácaros/hoja) de O. punicae, no influyeron significativamente en los índices de clorofila en las hojas de palto. Además, se determinó que no existe correlación entre los diferentes grados de infestación de O. punicae con el rendimiento de palto. En el presente trabajo no se pudo determinar el umbral de acción para esta plaga y cultivo, ya que los niveles poblacionales estudiados no mostraron un impacto estadísticamente significativo sobre el rendimiento.

ABSTRACT Avocado is a very important crop worldwide, and in Peru, being a relevant pest the mite Oligonychus punicae. The aim of this paper was to determine the effect of different levels of O. punicae populations on the chlorophyll content in avocado leaves and its impact on their yield, and to infer an economic and intervention threshold. A completely randomized design was carried out, there were 3 treatments each with a different population level corresponding to grades 2, 3 and greater than 3. A tree was taken as a sampling unit with 20 replications per treatment, the mite population was evaluated in 4 leaves per tree. These evaluations were carried out on a weekly basis throughout the campaign. The chlorophyll content of the 4 leaves per tree was evaluated in each treatment, likewise the production in each treatment (t ha-1) was also evaluated. The results showed that the different degrees of infestation studied: Grade 2 (1 - 10 mites / leaf), Grade 3 (11-25 mites / leaf), Grade 4 (26- 50 mites / leaf) and Grade 5 (greater than 50 mites / leaf) of O. Hirst did not influence the chlorophyll indices in the avocado leaves. It was also determined that there is no correlation between the different degrees of infestation of O. punicae Hirst with the avocado yield. In the present work, the mite action threshold could not yet be determined since the population levels studied did not show a statistically significant impact on yield performance.

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Dactylopius opuntiae is an insect pest that contains at least carminic acid, which has antioxidant properties. Since there is a relationship between the antioxidant ability and preservative action of compounds applied to meat products, the purpose of this study was to evaluate the antioxidant activity and usefulness of a D. opuntiae extract for beef patty preservation. The insects were bred and processed to obtain a liquid extract. For the extract, its carminic acid content, antioxidant activity against two free radicals, and actions on food quality parameters were determined. The D. opuntiae dry powder contained 2.91% w/w carminic acid, while the liquid extract exhibited an IC50 value of 3437.8 ± 67.8 and 19633.0 ± 674.5 µg/mL against the DPPH and ABTS radicals. Nevertheless, these antioxidant actions were lower than those found in a D. coccus extract. The D. opuntiae extract improved in a short time the redness and yellowness, eliminated the unfavorable effect of their vehicle on the MetMb level, and greatly reduced the TBARS formation. For the first time, an extract of D. opuntiae was applied to beef patties, and its beneficial antioxidant action on meat acceptance parameters was confirmed, which has potential commercial applications.

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Bacillus thuringiensis is a worldwide known bacterium for its capacity to control insect pests thanks to the action of its parasporal crystal. The objective of this paper deals with the history, in some cases unknown, of the study of Bacillus thuringiensis that led it to be a crucial biological alternative in controlling pest insects. How the mode of action for killing insects was understood, as well as the field tests that were carried out to evaluate its effectiveness and to develop the first commercial products, are reflected in this review that presents and discusses the scientific successes and failures that marked the course of B. thuringiensis.

Bacillus thuringiensis es una bacteria conocida mundialmente por su capacidad para controlar insectos plaga, gracias a la acción de su cristal parasporal. El objetivo de esta revisión trata de la historia, en algunos casos desconocida, del estudio de Bacillus thuringiensis que la llevó a ser una importante alternativa biológica en el control de insectos plaga. Cómo se llegó a comprender el modo de acción para matar insectos, así como las pruebas de campo que se realizaron para evaluar su efectividad y lograr desarrollar los primeros productos comerciales están plasmados en esta revisión que presenta y discute los aciertos y desaciertos científicos que marcaron el rumbo de B. thuringiensis.

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A 76-year literature survey and meta-analyses were carried out to recognize the trends, biases, and knowledge gaps of studies focusing on major groups of compounds of botanical origin, or phytochemicals, as insecticides. The survey found that the main phytochemicals prospected as insecticides belong to the following major chemical groups: terpenoids, terpenes, and carbonyl, all of which were tested, mainly against beetles (Coleoptera), caterpillars (i.e., larvae of Lepidoptera), and mosquitoes and other flies (i.e., Diptera). These studies are burgeoning at an exponential rate, with an evident focus on mortality endpoint estimates, but they are also neglecting sublethal assessments. China and India in Asia, as well as Brazil in the Americas, were responsible for most studies. The majority of the papers used stored grain insects as experimental models, which limits the applicability and representativeness of the findings. As a result, the main modes of exposure tested were fumigation and contact, which leads to the prevalence of estimates of lethal concentration in these studies. Therefore, a broader range of insect species deserves testing, with suitable modes of exposure identifying and characterizing the main molecules responsible for the insecticidal activity, which is seldom performed. Attention to these needs will circumvent current biases and allow the recognition of the main patterns of association between the origin and structure of phytochemicals and their insecticidal effects.

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Natural biological control is a key factor that ensures the regulation of insect pest populations in agroecosystems. However, the indiscriminate use of pesticides has compromised this environmental service. Thus, the search for environmentally safe pesticides is an increasing requirement for sustainable food production. In this study, we analyzed the toxicity of essential oils from two accessions (CGR112 and CGR126) of Croton grewioides and its major compounds, methyl eugenol and eugenol, on the soybean pest Chrysodeixis includens. In addition, we investigated the sublethal effects of these compounds on the predatory bug Podisus nigrispinus, analyzing its developmental, reproduction and life table parameters. Essential oils and their major compounds were toxic to C. includens and P. nigrispinus. In general, the presence of eugenol made the essential oil more toxic to the pest and selective to the natural enemy. Eugenol was the most toxic compound for 2nd instar larvae of C. includens at LD50, followed by CGR126 essential oil from C. grewioides which was equally toxic at higher doses. The estimated lethal times for essential oils to cause mortality in 50% of the population of C. includens were less than 15 h. There was selectivity of the essential oil of CGR126 accession of C. grewioides at lethal doses above 90%. Although the treatments showed little effect on the development of P. nigrispinus, body mass and reproductive parameters were negatively affected, with the exception of the essential oil of CGR126 accession of C. grewioides. The essential oil of C. grewioides may be a promising active ingredient for the synthesis of new insecticides, which are efficient against C. includens and at the same time are safer for the natural enemy P. nigrispinus.

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The scale mealybug, Diaspis echinocacti (Bouché, 1833) (Hemiptera: Diaspididae), is one of the main pests of the cactus pear in Brazil. The objective was to study biological aspects of D. echinocacti at the constant temperatures of 25, 28, 30, 33 and 35 °C with relative humidity of 60 ± 10% and photoperiod of 12 hours in the laboratory on the cactus pear cultivar, "Orelha de Elefante Mexicana", Opuntia stricta [Haw.] Haw. The development period (22 to 35 days) and survival in the egg (92 to 100%) and nymph (21.8 to 100%) stages and of the egg-adult cycle (20 to 100%), longevity (34.1 to 59.6 days) and fecundity (33 to 112 eggs) of D. echinocacti females with the different temperature and absence of males at the highest temperatures (> 30°C), indicated that the range between 25 °C and 30°C is the most favorable for this scale mealybug. This information may help to improve integrated management programs for D. echinocacti, in areas subject to seasonal temperature changes in the Brazilian regions where cactus pear is cultivated.

A cochonilha-escama, Diaspis echinocacti (Bouché, 1833) (Hemiptera: Diaspididae), é uma das principais pragas da palma forrageira no Brasil. O objetivo foi estudar aspectos biológicos de D. echinocacti nas temperaturas constantes de 25, 28, 30, 33 e 35 °C, umidade relativa de 60 ± 10% e fotoperíodo de 12 horas em laboratório na cultivar de palma forrageira, "Orelha de Elefante Mexicana", Opuntia stricta [Haw.] Haw. O período de desenvolvimento (22 a 35 dias) e a sobrevivência nas fases de ovo (92 a 100%) e ninfa (21,8 a 100%) e o ciclo ovo-adulto (20 a 100%), longevidade (34,1 a 59,6 dias) e fecundidade (33 a 112 ovos) de fêmeas de D. echinocacti nas diferentes temperaturas e ausência de machos nas maiores (> 30°C) indicam ser a faixa entre 25°C e 30°C a mais favorável para esta cochonilha de escama. Essas informações podem auxiliar no aprimoramento de programas de manejo integrado de D. echinocacti em áreas sujeitas a variações sazonais de temperatura nas regiões brasileiras onde a palma forrageira é cultivada.

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ABSTRACT The Cerambycidae Oncideres impluviata (Germar, 1823) is an important insect pest for Acacia mearnsii De Wild in Southern Brazil. The damage caused by their girdling behavior reduces tree productivity, specially in the early years of plant establishment, when girdling is performed on the main trunk of trees. Here, we used a fragment of the mtDNA COI gene to analyze the genetic diversity, population structure and demography of O. impluviata in Southern Brazil, as well as to present the first hypothesis of phylogenetic relationships among species of the genus Oncideres. Our results identified five distinct haplotypes among the populations of O. impluviata, with the most common haplotype identified as O.imp_COI_01. The phylogenetic inferences corroborated the monophyly of O. impluviata with maximum statistical support. In addition, the phylogeny recovered three main population strains that are largely congruent with the haplotype network, which includes two lineages that are found in different edaphic regions of Rio Grande do Sul (Serra do Sudeste and Encosta Inferior do Nordeste). This is the first molecular phylogenetic assessment of O. impluviata. Our findings provide insights into the evolution of a significant species for the Brazilian forestry sector, as well as new resources for planning of pest management strategies.

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Common bean (Phaseolus vulgaris L.) is a staple food in Brazil with both nutritional and socioeconomic importance. As an orphan crop, it has not received as much research attention as the commodity crops. Crop losses are strongly related to virus diseases transmitted by the whitefly Bemisia tabaci, one of the most important agricultural pests in the world. The main method of managing whitefly-transmitted viruses has been the application of insecticides to reduce vector populations. Compared to chemical vector control, a more sustainable strategy for managing insect-borne viruses is the development of resistant/tolerant cultivars. RNA interference has been applied to develop plant lines resistant to the whitefly in other species, such as tomato, lettuce and tobacco. Still, no whitefly-resistant plant has been made commercially available to date. Common bean is a recalcitrant species to in vitro regeneration; therefore, stable genetic transformation of this plant has been achieved only at low frequencies (<1%) using particle bombardment. In the present work, two transgenic common bean lines were obtained with an intron-hairpin construct to induce post-transcriptional gene silencing against the B. tabaci vATPase (Bt-vATPase) gene, with stable expression of siRNA. Northern blot analysis revealed the presence of bands of expected size for siRNA in leaf samples of the line Bt-22.5, while in the other line (11.5), the amount of siRNA produced was significantly smaller. Bioassays were conducted with both lines, but only the line Bt-22.5 was associated with significant mortality of adult insects (97% when insects were fed on detached leaves and 59% on the whole plant). The expression of the Bt-vATPase gene was 50% lower (p < 0.05) in insects that fed on the transgenic line Bt-22.5, when compared to non-transgenic controls. The transgenic line did not affect the virus transmission ability of the insects. Moreover, no effect was observed on the reproduction of non-target organisms, such as the black aphid Aphis craccivora, the leafminer Liriomyza sp. and the whitefly parasitoid Encarsia formosa. The results presented here serve as a basis for the development of whitefly-tolerant transgenic elite common bean cultivars, with potential to contribute to the management of the whitefly and virus diseases.

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RESUMEN La broca del café, Hypothenemus hampei, es un insecto plaga que causa daños significativos al grano de café y grandes pérdidas económicas a los productores en todo el mundo. Al igual que otros insectos, la broca de café requiere de quitina sintasas (CHS) para la biosíntesis de la quitina, componente principal del exoesqueleto del insecto, y de vital importancia para su crecimiento y desarrollo. En este estudio, el gen CHS1 de la broca del café (HhCHS1) fue identificado, caracterizado y posteriormente silenciado mediante el uso de ARNi, mecanismo que permite degradar el ARNm e interrumpir la expresión de proteínas de interés en un organismo. Los perfiles de expresión del gen HhCHS1, medidos por RT-qPCR, mostraron niveles de expresión diferencial en las diferentes etapas del desarrollo del insecto. Los niveles más altos de expresión se encontraron en larvas de segundo estadio (L2) y machos adultos. El ARNcd administrado por vía oral, a concentraciones de 2 µg/100 µL, generó un silenciamiento efectivo del gen HhCHS1 (84 %) después de 7 días de tratamiento. Estos resultados sugieren que el gen HhCHS1 desempeña un papel importante en el desarrollo del insecto, y que, por ende, podría usarse como objetivo para desarrollar nuevas estrategias de manejo de este insecto plaga, mediante el uso de ARNi.

ABSTRACT The coffee berry borer, Hypothenemus hampei, is an insect pest that causes significant damage to the grain and profound economic losses to coffee crops and producers worldwide. Like other insects, the coffee berry borer requires chitin synthases (CHS) for the biosynthesis of chitin, which is the main component of the insect exoskeleton, as well as a component of vital importance for their growth and development. In this study, the coffee berry borer CHS1 gene (HhCHS1) was identified, characterized, and subsequently silenced by using RNAi, a mechanism that allows mRNA to be degraded, interrupting the expression of the proteins of interest in an organism. The expression profiles of the HhCHS1 gene, measured by RT-qPCR, showed levels of differential expression in the different stages of insect development. The highest levels of expression were found in second instar (L2) larvae and adult males. Orally administered dsRNA, at concentrations of 2 µg/100 µL, was able to generate effective HhCHS1 silencing (84 %) after 7 days of treatment. These results suggest that the HhCHS1 gene plays an important role in the development of the coffee berry borer that could be used as target to develop new management strategies of this insect pest by using RNAi.

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Spodoptera frugiperda is a major pest of maize crops. The application of synthetic insecticides and the use of Bt maize varieties are the principal strategies used for its control. However, due to the development of pesticide resistance and the negative impact of insecticides on the environment, natural alternatives are constantly being searched for. Accordingly, the objective of this review was to evaluate the use of essential oils (EOs) as natural alternatives for controlling S. frugiperda. This review article covers the composition of EOs, methods used for the evaluation of EO toxicity, EO effects, and their mode of action. Although the EOs of Ocimum basilicum, Piper marginatum, and Lippia alba are the most frequently used, Ageratum conyzoides, P. septuplinervium. O. gratissimum and Siparuna guianensis were shown to be the most effective. As the principal components of these EOs vary, then their mode of action on the pest could be different. The results of our analysis allowed us to evaluate and compare the potential of certain EOs for the control of this insect. In order to obtain comparable results when evaluating the toxicity of EOs on S. frugiperda, it is important that methodological issues are taken into account.

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The lesser mealworm (LMW) is the most important pest in poultry production. Insects are associated to avian pathogens, mainly Salmonella. Its control is based on chemical insecticide, with limited efficacy in population reduction. Also, insect populations are resistant to the main active ingredients used. Diatomaceous earth (DE) is a mineral dust that has activity against the LMW when used in dust application. No information is available about DE liquid preparation against this insect. Thus, bioassays were conducted aiming to develop a strategy for DE liquid preparation to this insect control. In laboratory the ideal concentration for poultry house experiment was estimated and the effect of insect contact with poultry litter or chicken feed after application was checked. In the poultry house, DE liquid preparation (10% in water, 1 L·m­2) was applied on the dirt soil of a cleaned and empty poultry house. In the control poultry house, a chemical insecticide was used (cypermethrin 15 g + chlorpyriphos 25 g + piperonyl butoxide 15 g) (1 L·m­2). DE at all concentrations was efficient mainly when insects were dried for 24 h before contact with a substrate. In poultry house, both treatments obtained similar results at 15 days after treatment (94% of reduction of insect population). At 45 days after treatment, the insect population with DE treatment increased 39% while the insect population remained 17% smaller than the initial population with a chemical insecticide. DE liquid preparation has potential to be used as a safe treatment in LMW population management, as a shock treatment.

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Essential oils (EOs) are widely recognized as efficient and safe alternatives for controlling pest insects in foods. However, there is a lack of studies evaluating the toxicological stability of botanical insecticides in stored grains in order to establish criteria of use and ensure your efficiency. The objective of this work was to evaluate the toxicological stability of basil essential oil (O. basilicum) and its linalool and estragole components for Sitophilus zeamais (Motschulsky) adults in corn grains by fumigation. The identification of the chemical compounds of the essential oil was performed with a gas chromatograph coupled to a mass selective detector. Mortality of insects was assessed after 24 h exposure. After storage for six (EO) and two months (linalool and estragole) under different conditions of temperature (5, 20, and 35 °C) and light (with and without exposure to light), its toxicological stability was evaluated. Studies revealed that the essential oil of O. basilicum and its main components exhibited insecticidal potential against adults of S. zeamais. For greater toxicological stability, suitable storage conditions for them include absence of light and temperatures equal to or less than 20 °C.

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Bacillus thuringiensis (Bt)-based bioinsecticides and transgenic plants expressing proteins with insecticidal activity (Cry and Vip) have been successfully used in several integrated pest management programs worldwide. Lepidoptera comprise some of the most economically important insect pests of the major agricultural crops. In this study, the toxicity of 150 Bt strains was evaluated against Helicoverpa armigera (Hübner) larvae. Eight strains (426, 520B, 1636, 1641, 1644, 1648, 1657 and 1658) showed high insecticide activity against H. armigera and were therefore tested against Anticarsia gemmatalis (Hübner), Spodoptera cosmioides (Walker), Chrysodeixis includens (Walker), and Diatraea saccharalis (Fabricius) larvae. Our results showed that most of the Bt strains were also toxic to these lepidopteran species. The biochemical and molecular analyses of these strains revealed that they had a similar protein profile; however, their cry and vip gene contents were variable. In addition, the median lethal concentration (LC50) of the selected strains indicated that the strains 1636, 1641, and 1658 were the most effective against H. armigera, showing LC50 values of 185.02, 159.44, and 192.98 ng/cm2, respectively. Our results suggest that the selected Bt strains have great potential to control the lepidopteran pests H. armigera, A. gemmatalis, D. saccharalis, S. cosmioides, and C. includes.

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Percolaspis ornata (Germar) (Coleoptera, Chrysomelidae) is known in Brazil as an important pest of cocoa in the states of Bahia and Espírito Santo. We recently identified a Chrysomelidae species feeding and causing damage to soybean, corn, and cotton crops in the state of Mato Grosso, Brazil. The species was identified as Percolaspis cf. ornata. Adults feed on young leaves and sprouts and, in many cases, cut the stem of seedlings, causing stand reduction and yield losses. Its attacks have been recorded since 2016 in the central region of Mato Grosso. Because of the importance of the state of Mato Grosso as the main grain producer in the country, it is necessary to monitor crops for the occurrence of this insect in the next harvests and the development of basic and applied studies aimed at defining management strategies for this emerging pest. This is the first record of P. cf. ornata causing damage to soybean, maize, and cotton crops in Brazil.

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Anastrepha ludens (Loew) is one of the most destructive insect pests damaging several fruits of economic importance. The sterile insect technique (SIT) is used under an area-wide integrated pest management approach, to suppress these pest populations. Mass rearing facilities were initially established to produce sterile males of bi-sexual strains in support of SIT. The first genetic sexing strain (GSS) for A. ludens, Tapachula-7, based on pupal color dimorphism, was a key development since the release of males-only significantly increases the SIT efficiency. In this study, we document the development of a novel pupal color-based GSS. Twelve radiation-induced translocation lines were assessed as potential GSS in terms of recombination rates and rearing efficiency at a small scale. The best one, GUA10, was cytogenetically characterized: it was shown to carry a single translocation between the Y chromosome and chromosome 2, which is known to carry the black pupae marker. This GSS was further evaluated at medium and large scales regarding its genetic stability, productivity and quality versus Tapachula-7. GUA10 presented better genetic stability, fecundity, fertility, production efficiency, flying ability, and male mating, clear indicators that GUA10 GSS can significantly improve the efficacy and cost-effectiveness of SIT applications against this pest species.

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The small tomato borer, Neoleucinodes elegantalis (Guenée, 1854) is a multivoltine pest of tomato and other cultivated solanaceous plants. The knowledge on how N. elegantalis respond to temperature may help in the development of pest management strategies, and in the understanding of the effects of climate change on its voltinism. In this context, this study aimed to select models to describe the temperature-dependent development rate of N. elegantalis and apply the best models to evaluate the impacts of climate change on pest voltinism. Voltinism was estimated with the best fit non-linear model and the degree-day approach using future climate change scenarios representing intermediary and high greenhouse gas emission rates. Two out of the six models assessed showed a good fit to the observed data and accurately estimated the thermal thresholds of N. elegantalis. The degree-day and the non-linear model estimated more generations in the warmer regions and fewer generations in the colder areas, but differences of up to 41% between models were recorded mainly in the warmer regions. In general, both models predicted an increase in the voltinism of N. elegantalis in most of the study area, and this increase was more pronounced in the scenarios with high emission of greenhouse gases. The mathematical model (74.8%) and the location (9.8%) were the factors that mostly contributed to the observed variation in pest voltinism. Our findings highlight the impact of climate change on the voltinism of N. elegantalis and indicate that an increase in its population growth is expected in most regions of the study area.

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