RESUMEN
The green-belly stink bug (Diceraeus melacanthus Dallas (Hemiptera: Pentatomidae)) is a key pest of corn-soybean crop systems and the management of this pest is difficult due to behavioral characteristics. However, products that alter its behavior, such as arrestants, dislodgers, and phagostimulants, have been used in an attempt to improve the effectiveness of chemical control. In this study, the effect of these products on the walking behavior of nymphs and adults of D. melacanthus was initially evaluated through computational behavioral tracking (Ethovision system). Adults of D. melacanthus exposed to the dislodgers Creolin Pearson and Quimifol S450 (sulfur) significantly increased the distance covered and the walking speed. On the other hand, the only treatment that significantly affected the walking behavior of nymphs was the treatment with soy milk (phagostimulant). The physical-chemical analyses indicated considerable changes in the pH and electrical conductivity of mixtures of such products with insecticides from different chemical groups, as well as lack of homogeneity (physical incompatibility). Nevertheless, none of the products tested improved the control efficacy of an insecticide based on imidacloprid + beta-cyfluthrin, either in laboratory tests (contact bioassay) or in tests conducted in corn crops during 2 crop harvests. Thus, the association of these products in a tank mixture does not increase the control levels of D. melacanthus in post-emergence of maize and may have an antagonistic effect in some associations.
Asunto(s)
Heterópteros , Insecticidas , Animales , Glycine max , Zea mays , Ninfa , CaminataRESUMEN
ABSTRACT: We evaluated under field conditions the toxicity of insecticides previously identified as harmful in laboratory and semifield bioassays on the parasitoid Trichogramma pretiosum (Hymenoptera: Trichogrammatidae). The experiments were conducted during the 2019/20 and 2020/21 harvests in rice fields. Following the recommendations of the International Organization for Biological and Integrated Control (IOBC), four insecticides were applied in 64 m2 experimental plots. Subsequently, T. pretiosum was released inundatively. To verify parasitism rates, at 1, 2, 4 and 6 days after release (DAR) of the parasitoids, eggs from the host Ephestia kuehniella (Lepidoptera: Pyralidae) were offered. After determining the number of parasitized eggs, the data were grouped into a reduction coefficient (Ex) to provide a single result for the effects of the insecticides on parasitoid. For both the 2019/20 and 2020/21 evaluated crops, it was found that at 2 DAR, the highest parasitism rates occurred. In contrast, in 6 DAR, no parasitism rates were observed. Lambda-cyhalothrin, thiamethoxam, and zeta-cypermethrin were classified as moderately harmful; thiamethoxam + lambda-cyhalothrin was classified as harmful. Following IOBC guidelines, the toxicity of these products under field conditions is lower than that obtained in the laboratory or semi-field for the T. pretiosum. However, these insecticides should be avoided, or used at times that do not coincide with the release or presence of the parasitoid in the field.
RESUMO: Avaliamos em condições de campo a toxicidade de inseticidas previamente identificados como nocivos em bioensaios de laboratório e semicampo sobre o parasitóide Trichogramma pretiosum (Hymenoptera: Trichogrammatidae). Os experimentos foram conduzidos durante as safras 2019/20 e 2020/21 em lavouras de arroz. Seguindo as recomendações da International Organization for Biological and Integrated Control (IOBC), quatro inseticidas foram aplicados em parcelas experimentais de 64 m2. Posteriormente, realizou-se uma liberação inundativa de T. pretiosum. Para verificar as taxas de parasitismo, aos 1, 2, 4 e 6 dias após a liberação (DAR) dos parasitoides, ovos do hospedeiro Ephestia kuehniella (Lepidoptera: Pyralidae) foram ofertados. Após a determinação do número de ovos parasitados, os dados foram agrupados em um coeficiente de redução (Ex) para fornecer um resultado único para os efeitos dos inseticidas sobre o parasitoide. Tanto para as safras 2019/20 quanto 2020/21, verificou-se que em 2 DAR, ocorreram as maiores taxas de parasitismo. Em contraste, aos 6 DAR, não foram observadas taxas de parasitismo. Lambda-cialotrina, tiametoxam e zeta-cipermetrina foram classificados como moderadamente nocivos; tiametoxam + lambda-cialotrina foi classificado como prejudicial. Seguindo as diretrizes da IOBC, a toxicidade desses produtos em condições de campo é inferior à obtida em laboratório ou semi-campo para o T. pretiosum. Entretanto, esses inseticidas devem ser evitados, ou utilizados em momentos que não coincidam com a liberação ou presença do parasitoide a campo.
RESUMEN
We evaluated under field conditions the toxicity of insecticides previously identified as harmful in laboratory and semifield bioassays on the parasitoid Trichogramma pretiosum (Hymenoptera: Trichogrammatidae). The experiments were conducted during the 2019/20 and 2020/21 harvests in rice fields. Following the recommendations of the International Organization for Biological and Integrated Control (IOBC), four insecticides were applied in 64 m2 experimental plots. Subsequently, T. pretiosum was released inundatively. To verify parasitism rates, at 1, 2, 4 and 6 days after release (DAR) of the parasitoids, eggs from the host Ephestia kuehniella (Lepidoptera: Pyralidae) were offered. After determining the number of parasitized eggs, the data were grouped into a reduction coefficient (Ex) to provide a single result for the effects of the insecticides on parasitoid. For both the 2019/20 and 2020/21 evaluated crops, it was found that at 2 DAR, the highest parasitism rates occurred. In contrast, in 6 DAR, no parasitism rates were observed. Lambda-cyhalothrin, thiamethoxam, and zeta-cypermethrin were classified as moderately harmful; thiamethoxam + lambda-cyhalothrin was classified as harmful. Following IOBC guidelines, the toxicity of these products under field conditions is lower than that obtained in the laboratory or semi-field for the T. pretiosum. However, these insecticides should be avoided, or used at times that do not coincide with the release or presence of the parasitoid in the field.
Avaliamos em condições de campo a toxicidade de inseticidas previamente identificados como nocivos em bioensaios de laboratório e semicampo sobre o parasitóide Trichogramma pretiosum (Hymenoptera: Trichogrammatidae). Os experimentos foram conduzidos durante as safras 2019/20 e 2020/21 em lavouras de arroz. Seguindo as recomendações da International Organization for Biological and Integrated Control (IOBC), quatro inseticidas foram aplicados em parcelas experimentais de 64 m2. Posteriormente, realizou-se uma liberação inundativa de T. pretiosum. Para verificar as taxas de parasitismo, aos 1, 2, 4 e 6 dias após a liberação (DAR) dos parasitoides, ovos do hospedeiro Ephestia kuehniella (Lepidoptera: Pyralidae) foram ofertados. Após a determinação do número de ovos parasitados, os dados foram agrupados em um coeficiente de redução (Ex) para fornecer um resultado único para os efeitos dos inseticidas sobre o parasitoide. Tanto para as safras 2019/20 quanto 2020/21, verificou-se que em 2 DAR, ocorreram as maiores taxas de parasitismo. Em contraste, aos 6 DAR, não foram observadas taxas de parasitismo. Lambda-cialotrina, tiametoxam e zeta-cipermetrina foram classificados como moderadamente nocivos; tiametoxam + lambda-cialotrina foi classificado como prejudicial. Seguindo as diretrizes da IOBC, a toxicidade desses produtos em condições de campo é inferior à obtida em laboratório ou semi-campo para o T. pretiosum. Entretanto, esses inseticidas devem ser evitados, ou utilizados em momentos que não coincidam com a liberação ou presença do parasitoide a campo.
Asunto(s)
Oryza/parasitología , Control Biológico de Vectores , Himenópteros/efectos de los fármacos , Insecticidas/toxicidadRESUMEN
The rice water weevil, Oryzophagus oryzae (Coleoptera: Curculionidae), is an economically important pest of flooded rice paddies throughout South America, and species with similar life histories are present in many rice-producing regions globally (collectively referred to here as RWWs). Plant resistance is a key strategy for management of RWWs; however, the mechanisms responsible for rice resistance to RWWs are poorly understood. We investigated morphoanatomical and biochemical plant traits potentially involved in rice resistance to O. oryzae. Resistance-associated traits were characterized in two cultivars, 'Dawn' (resistant) and 'BRS Pampa CL' ('Pamp' = susceptible), which were selected from among six cultivars on 2-year field screenings. Anatomical and morphological traits of leaf tissues from 'Pamp' and 'Dawn' were similar, which perhaps explains the lack of antixenosis during host plant selection. However, significant antibiosis effects were found. The activities of antioxidant enzymes involved in plant defense, as well the content of hydroxycinnamic and hydroxybenzoic acids derivatives and lignin, were higher in roots of 'Dawn' than in 'Pamp', over the period of larval infestation in the field. Additionally, 'Dawn' exhibited a root sclerenchyma arranged in three layers of lignified cells, which differed from the arrangement of cells in 'Pamp', regardless of larval infestation. Our results provide the first evidence for specific resistance-related traits associated with mortality and malnutrition of RWWs in rice.
Asunto(s)
Escarabajos , Oryza , Gorgojos , Animales , Humanos , Larva , AguaRESUMEN
Trichopria anastrephae Costa Lima, 1940 (Hymenoptera: Diapriidae) is a pupal endoparasitoid of Drosophila suzukii Matsumura, 1931 (Diptera: Drosophilidae) in Brazil. This species is of great agricultural importance and is almost exclusively managed by organophosphate, spinosyn, pyrethroid, neonicotinoid, and avermectin insecticides. However, frequent application of insecticides can have negative effects on the parasitoid. The objective of this study was to evaluate the lethal and transgenerational toxicity of five insecticides on T. anastrephae adults during the F0, F1, and F2 generations. Drosophila suzukii puparia were sprayed prior to their exposure to T. anastrephae for 24 h. Parameters evaluated in generation F0 were mortality and rate of parasitism. After the emergence of the F1 generation, the emergence rate and sex ratio were analyzed. Then, pairs of parasitoids were selected from F1 and pupae; the host was offered to evaluate parasitism, emergence, and sex ratio of the F2 generation. In the F0 generation, malathion was the only insecticide that caused 100% mortality of adults of T. anastrephae. However, all insecticides tested affected the parasitism rate, being classified as moderately to slightly harmful. In F1, the emergence of T. anastrephae was also affected, making the insecticides moderately to slightly harmful. However, there were no significant differences in the sex ratio and parasitism rate or the parameters evaluated in F2, which means that all products were classified as harmless. These results are important for the development of Integrated Management programs for D. suzukii and for the conservation of natural populations of T. anastrephae in the field.
Asunto(s)
Himenópteros , Insecticidas , Animales , Drosophila , Insecticidas/toxicidad , Neonicotinoides , PupaRESUMEN
The larval-pupal endoparasitoid Diachasmimorpha longicaudata (Ashmead, 1905) is considered one of the main biological control agents of fruit flies Ceratitis capitata Wiedemann (1824) and Anastrepha fraterculus Wiedemann (1830) in Central and South America. The application of pesticides for disease and insect-pest management in fruit species may have adverse effects on the parasitoid. The objective of this study was to evaluate the lethal and sublethal effects via residual contact of commercial pesticide formulations on D. longicaudata. The active ingredients thiamethoxam, indoxacarb, chlorpyrifos, deltamethrin, spinetoram, spinosad, phosmet, lambda-cyhalothrin, malathion, dimethoate, and methidationa showed high toxicity to adults (100% mortality) after 96 h and were classified as harmful (Class 4). In contrast, the formulations of azadirachtin (Agroneem 850 EC, Azact 2.4 EC, Azamax 12 EC, and Fitoneem 850 EC), chlorantraniliprole, bordeaux mixture, sulfur, lufenuron, lime sulphur, novalurom, and mancozeb were rated as innocuous (<10% mortality). In addition, the formulations azadirachtin did not reduce the parasitism and the emergence rate of the F0 generation, the same pesticides added to chlorantraniliprole, azadirachtin A+B (Agroneem 850 EC), and lufenuron did not cause reduction in parasitism and emergence rate of the F1 generation of D. longicaudata. The use of pyrethroids, organophosphates, spinosyns, oxadiazines, and neonicotinoids should be used with caution in IPM programs. While pesticides chlorantraniliprole, azadirachtin formulations, bordeaux mixture, lufenuron, lime sulphur, and mancozeb do not cause lethal and sublethal effects for D. longicaudata adults. The results of this study provide important information for use in integrated pest management programs for fruit fly management.
Asunto(s)
Ceratitis capitata , Himenópteros , Plaguicidas , Tephritidae , Avispas , Animales , PupaRESUMEN
This work aimed to evaluate the residual action of five insecticides on larvae and adults of the predators Chrysoperla externa (Hagen) and Eriopis connexa (Germar). The insecticides gamma-cyhalothrin, imidacloprid+beta-cyfluthrin, methomyl, thiamethoxam, and thiamethoxam+lambda-cyhalothrin were sprayed in pod bean plants until the point of runoff. Weekly, at 3, 10, 17, 24, and 31 days, first instar larvae and adults of both predators were exposed to leaves containing dry residues of the insecticides. Based on the mortality observed throughout the bioassays, the insecticides were classified according to the scale of the residual effects proposed by the International Organization for Biological and Integrated Control (IOBC). Except for thiamethoxam+lambda-cyhalothrin, which was moderately persistent (class 3) to larvae of C. externa and E. connexa, all other tested insecticides were persistent (class 4) to larvae of both species. Gamma-cyhalothrin, imidacloprid + beta-cyfluthrin, and methomyl were persistent (class 4) to C. externa adults, while thiamethoxam was moderately persistent (class 3) and thiamethoxam + lambda-cyhalothrin was slightly persistent (class 2) to the adult stage. As for E. connexa adults, imidacloprid + beta-cyfluthrin and methomyl were persistent (class 4) and gamma-cyhalothrin, thiamethoxam, and thiamethoxam + lambda-cyhalothrin were moderately persistent (class 3). Thus, due to extended residual effect, these insecticides must be avoided when larvae and adults of both predators are active in the crop.
Asunto(s)
Escarabajos , Insecticidas , Piretrinas , Animales , Insecticidas/toxicidad , Larva , Piretrinas/toxicidad , TiametoxamRESUMEN
Trichogramma pretiosum is one of the main egg parasitoids used in the control of lepidopteran pests in Brazil. This natural enemy can be negatively affected by the use of insecticides, herbicides, and fungicides. The present work used a systematic review and meta-analysis to group information from multiple studies on the selectivity of pesticides (279 commercial products) in rice, corn, soybean, apple and peach crops for immature stages (egg-larva, pre-pupa, and pupa) and adult parasitoids. The selected studies used the International Organization for Biological and Integrated Control (IOBC) methodology with the same adaptations for T. pretiosum. The meta-analysis found that corn crops had the highest frequency of tests (2 0 7). The most frequently tested active ingredients (a.i.) were glyphosate, glyphosate isopropylamine salt, and sulfur at frequencies of 41, 32 and 24 tests, respectively. The pesticides registered for rice crops showed the greatest sublethal effects on T. pretiosum, with an approximately 47% reduction in parasitism (RP) or emergence (RE). The adult stage of the parasitoid showed greater sensitivity to the tested pesticides (65% RP), in comparison to the immature stages. In general, insecticides showed superior toxicity for all development stages of T. pretiosum, compared to herbicides and fungicides, regardless of the recommended dosage for the crop. The present study aggregates information related to selectivity for the four life stages of T. pretiosum, contributing significantly to the integration of biological control and chemical control in rice, corn, soybean, apple and peach crops in Brazil.
Asunto(s)
Resistencia a Medicamentos/fisiología , Himenópteros/fisiología , Control Biológico de Vectores , Plaguicidas/farmacología , Animales , Brasil , Productos Agrícolas/parasitología , Himenópteros/crecimiento & desarrollo , Estadios del Ciclo de Vida/efectos de los fármacos , Enfermedades de las Plantas/parasitología , Enfermedades de las Plantas/prevención & controlRESUMEN
The use of pesticides is considered one of the most important threats to pollinators, especially since they are widely used in agriculture for pest control. In the last years, several studies have reported severe secondary effects on various bee species, including exotic and native bees. In this study, lethal (mortality) and sublethal (locomotor activity) effects of insecticides and acaricides used in strawberries in Brazil (abamectin, novaluron, spinetoram, and thiamethoxam) were evaluated on the native stingless bees Melipona quadrifasciata and Tetragonisca fiebrigi. The results showed that the effects varied significantly according to the pesticide, type of exposure (oral or topical), and bee species. Through oral exposure, M. quadrifasciata was more susceptible to all insecticides except for abamectin, while in topical exposure, T. fiebrigi was more sensitive. Thiamethoxam followed by spinetoram and abamectin were the most lethal, regardless of species or exposure route; novaluron was not harmful at the highest tested dose. The locomotor activity of bees was altered in the presence of sublethal doses (LC10 and LC50) of all insecticides. Spinetoram and abamectin can be as much as toxic as thiamethoxam against M. quadrifasciata and T. fiebrigi in laboratory experiments. These findings should be confirmed in field experiments to define possibilities to combine pest control and pollinator management. In crops like strawberries, the selectivity of native pollinators should be considered.
Asunto(s)
Fragaria , Himenópteros , Insecticidas , Animales , Abejas , Brasil , TiametoxamRESUMEN
Anastrepha grandis is one of the main pests related to Cucurbitaceae in South and Central America. This study discusses the impact of temperature increase on the number of generations of A. grandis, whose distribution could be aggravated due to temperature increase. Climatic variations were analyzed for reference scenarios obtained from 1961â1990 and of A2 and B1 climatic change scenarios of the Intergovernmental Panel on Climate Change, in which a less pessimistic scenario (B1) and a more pessimistic scenario (A2) were found. In relation to the reference scenarios, in colder seasons, the southern and southeastern regions are inadequate for the development of A. grandis, presenting one generation at most. In other regions of Brazil, where temperatures are higher throughout the year, the number of generations is at least two, and there is no variation from one climatic season to another. When analyzing the temperature increase, in a more pessimistic scenario (A2), there is a considerable variation in the number of generations, if we take into account three future climate scenarios in which A. grandis practically doubles the number of generations. In relation to a less pessimistic scenario (B1), there is a smaller variation in the number of generations, mainly in the southern region of the country. This variation is more accentuated in southeastern Brazil due to the temperature increase, in which the pest's number of generations doubles even in colder seasons.(AU)
Anastrepha grandis é uma das principais pragas relacionadas à Cucurbitaceae nas Américas do Sul e Central. O presente trabalho teve como objetivo conhecer o impacto do aumento da temperatura no número de gerações de A. grandis, cuja distribuição poderá ser agravada devido ao aumento da temperatura. Essas variações climatológicas foram analisadas para cenários de referência obtidos de 1961â1990 e nos cenários de mudanças climáticas A2 e B1 do Painel Intergovernamental de Mudanças Climáticas, onde encontramos um cenário menos pessimista (B1) e um mais pessimista (A2). Em relação ao período de referência é possível observar que, nas estações mais frias, as regiões Sul e Sudeste mostram-se inadequadas para o desenvolvimento de A. grandis, apresentando no máximo uma geração, enquanto nas estações mais quentes o inseto pode chegar a duas gerações. Nas demais regiões do país, onde as temperaturas apresentam-se mais elevadas durante todo o ano, o número de gerações é de no mínimo duas e não há variação de uma estação climática para outra. Quando analisado o aumento da temperatura, em um cenário mais pessimista (A2), é possível observar uma variação considerável no número de gerações nos três cenários climáticos futuros, podendo A. grandis dobrar o número de gerações. Em relação a um cenário menos pessimista (B1), é evidente uma variação menor no número de gerações, principalmente na região Sul do país, enquanto que na região Sudeste essa variação já é mais acentuada devido ao aumento da temperatura, podendo dobrar o número de gerações mesmo nas estações mais frias.(AU)
Asunto(s)
Cambio Climático , Cucurbitaceae , Tephritidae , Factores AbióticosRESUMEN
Anastrepha grandis is one of the main pests related to Cucurbitaceae in South and Central America. This study discusses the impact of temperature increase on the number of generations of A. grandis, whose distribution could be aggravated due to temperature increase. Climatic variations were analyzed for reference scenarios obtained from 1961â'1990 and of A2 and B1 climatic change scenarios of the Intergovernmental Panel on Climate Change, in which a less pessimistic scenario (B1) and a more pessimistic scenario (A2) were found. In relation to the reference scenarios, in colder seasons, the southern and southeastern regions are inadequate for the development of A. grandis, presenting one generation at most. In other regions of Brazil, where temperatures are higher throughout the year, the number of generations is at least two, and there is no variation from one climatic season to another. When analyzing the temperature increase, in a more pessimistic scenario (A2), there is a considerable variation in the number of generations, if we take into account three future climate scenarios in which A. grandis practically doubles the number of generations. In relation to a less pessimistic scenario (B1), there is a smaller variation in the number of generations, mainly in the southern region of the country. This variation is more accentuated in southeastern Brazil due to the temperature increase, in which the pest's number of generations doubles even in colder seasons.(AU)
Anastrepha grandis é uma das principais pragas relacionadas à Cucurbitaceae nas Américas do Sul e Central. O presente trabalho teve como objetivo conhecer o impacto do aumento da temperatura no número de gerações de A. grandis, cuja distribuição poderá ser agravada devido ao aumento da temperatura. Essas variações climatológicas foram analisadas para cenários de referência obtidos de 1961â'1990 e nos cenários de mudanças climáticas A2 e B1 do Painel Intergovernamental de Mudanças Climáticas, onde encontramos um cenário menos pessimista (B1) e um mais pessimista (A2). Em relação ao período de referência é possível observar que, nas estações mais frias, as regiões Sul e Sudeste mostram-se inadequadas para o desenvolvimento de A. grandis, apresentando no máximo uma geração, enquanto nas estações mais quentes o inseto pode chegar a duas gerações. Nas demais regiões do país, onde as temperaturas apresentam-se mais elevadas durante todo o ano, o número de gerações é de no mínimo duas e não há variação de uma estação climática para outra. Quando analisado o aumento da temperatura, em um cenário mais pessimista (A2), é possível observar uma variação considerável no número de gerações nos três cenários climáticos futuros, podendo A. grandis dobrar o número de gerações. Em relação a um cenário menos pessimista (B1), é evidente uma variação menor no número de gerações, principalmente na região Sul do país, enquanto que na região Sudeste essa variação já é mais acentuada devido ao aumento da temperatura, podendo dobrar o número de gerações mesmo nas estações mais frias.(AU)
Asunto(s)
Cambio Climático , Cucurbitaceae , Tephritidae , Factores AbióticosRESUMEN
Toxic bait formulations have been one of the main strategies used in apple orchards in southern Brazil for the control of South American fruit fly. However, its effects on the stingless bees Plebeia emerina (Friese) and Tetragonisca fiebrigi (Schwarz) are unknown. This study aimed to assess the toxicity, attraction and repellency of food lures and toxic baits on P. emerina and T. fiebrigi. We evaluated the food lures Anamed® (pure), Biofruit® (3%), Flyral® (1.25%), Sugarcane molasses (7%) and Samaritá Tradicional® (3%), in toxic baits formulations associated with spinosad (Tracer® 480SC) and malathion (Malathion® 1000EC), and the ready-to-use toxic baits Success® 0.02CB and Gelsura®. We obtained the mean lethal concentration (LC50) and the mean survival of workers after exposure to toxic bait formulations. In the field, we carried out attraction and repellency tests of toxic baits to foraging. The food lures associated with malathion and spinosad showed different levels of toxicity to P. emerina and T. fiebrigi. Sugarcane molasses and Samaritá Tradicional® associated with spinosad showed high toxicity, with LC50 values of 6.92 and 10.61â¯ng/µL diet to P. emerina, and of 4.37 and 15.48â¯ng/µL diet to T. fiebrigi, respectively. Gelsura® and food lures with malathion caused rapid workers mortality, with mean survival less than 3â¯h after exposure. No toxic bait formulation was attractive to P. emerina foragers in the field. Anamed®, Gelsura®, and Success® were repellent to P. emerina foragers.
Asunto(s)
Abejas/efectos de los fármacos , Control de Insectos/métodos , Insecticidas/toxicidad , Animales , Abejas/fisiología , Brasil , Drosophila , Combinación de Medicamentos , Insecticidas/química , Dosificación Letal Mediana , Macrólidos/química , Macrólidos/toxicidad , Malatión/química , Malatión/toxicidad , Análisis de SupervivenciaRESUMEN
This study aimed to assess, under laboratory conditions, the selectivity of nine pesticides used in peach to the egg and pupal stages of the predators Chrysoperla externa and Coleomegilla quadrifasciata. Tests consisted of the direct application of pesticides on eggs and pupae of predators and assessment of sublethal effects on fertility and fecundity of emerged adults. For eggs, the pesticides were classified according to the effects on the reduction of the percentage of larval hatching, while for pupae they were classified as a function of the total effect, according to the toxicity scale proposed by the International Organization for Biological and Integrated Control (IOBC). All the pesticides (used dose) were harmless (class 1) to eggs of C. externa, but abamectin (80) and copper + calcium (1%) were considered slightly harmful (class 2) to pupae. In bioassays with C. quadrifasciata, abamectin (80), deltamethrin (40), and malathion (150) were classified as slightly harmful (class 2), while fenitrothion (100) was moderately harmful (class 3) to predator eggs; in the pupal stage, abamectin (80), fenitrothion (100), and malathion (150) were considered harmful (class 4). Azadirachtin (1%), chlorantraniliprole (14), deltamethrin (40), copper + calcium (25% + 10%), and sulfur + calcium (3.5 Ba) were harmless (class 1) to eggs and pupae of C. externa and C. quadrifasciata and thus should be prioritized in sprayings for pest control in the IPM of peach.(AU)
Objetivou-se com este trabalho avaliar em laboratório a seletividade de nove produtos fitossanitários utilizados na cultura do pessegueiro sobre as fases de ovo e pupa dos predadores Chrysoperla externa e Coleomegilla quadrifasciata. Os ensaios consistiram da aplicação direta dos agrotóxicos sobre ovos e pupas dos predadores e avaliação de efeitos subletais na fertilidade e fecundidade dos adultos emergidos. Para ovos, os produtos fitossanitários foram classificados em função dos efeitos na redução da porcentagem de eclosão de larvas, e para pupas em função do efeito total, conforme a escala de toxicidade proposta pela International Organization for Biological and Integrated Control (IOBC). Todos os produtos fitossanitários (dosagem utilizada) foram inócuos (classe 1) aos ovos de C. externa, entretanto, abamectina (80) e cobre + cálcio (1%) foram considerados levemente nocivos (classe 2) às pupas. Nos bioensaios com C. quadrifasciata, abamectina (80), deltametrina (40) e malationa (150) foram classificados como levemente nocivos (classe 2), enquanto fenitrotiona (100) apresentou-se como moderadamente nocivo (classe 3) aos ovos do predador; para a fase de pupa, abamectina (80), fenitrotiona (100) e malationa (150) foram nocivos (classe 4). Os produtos Azadiractina (1%), clorantraniliprole (14), deltametrina (40), cobre + cálcio (25% + 10%) e enxofre + cálcio (3,5 Ba) são inócuos (classe 1) aos ovos e pupas de C. externa e C. quadrifasciata, e assim devem ser priorizados em pulverizações visando ao controle de pragas no MIP pessegueiro.(AU)
Asunto(s)
Insectos/efectos de los fármacos , Insectos/crecimiento & desarrollo , Escarabajos/crecimiento & desarrollo , Escarabajos/efectos de los fármacos , Control de Plagas/métodos , Plagas Agrícolas , Prunus persica/efectos adversos , Agroquímicos/administración & dosificación , Agroquímicos/análisis , Agroquímicos/toxicidadRESUMEN
This study aimed to assess, under laboratory conditions, the selectivity of nine pesticides used in peach to the egg and pupal stages of the predators Chrysoperla externa and Coleomegilla quadrifasciata. Tests consisted of the direct application of pesticides on eggs and pupae of predators and assessment of sublethal effects on fertility and fecundity of emerged adults. For eggs, the pesticides were classified according to the effects on the reduction of the percentage of larval hatching, while for pupae they were classified as a function of the total effect, according to the toxicity scale proposed by the International Organization for Biological and Integrated Control (IOBC). All the pesticides (used dose) were harmless (class 1) to eggs of C. externa, but abamectin (80) and copper + calcium (1%) were considered slightly harmful (class 2) to pupae. In bioassays with C. quadrifasciata, abamectin (80), deltamethrin (40), and malathion (150) were classified as slightly harmful (class 2), while fenitrothion (100) was moderately harmful (class 3) to predator eggs; in the pupal stage, abamectin (80), fenitrothion (100), and malathion (150) were considered harmful (class 4). Azadirachtin (1%), chlorantraniliprole (14), deltamethrin (40), copper + calcium (25% + 10%), and sulfur + calcium (3.5 Ba) were harmless (class 1) to eggs and pupae of C. externa and C. quadrifasciata and thus should be prioritized in sprayings for pest control in the IPM of peach.
Objetivou-se com este trabalho avaliar em laboratório a seletividade de nove produtos fitossanitários utilizados na cultura do pessegueiro sobre as fases de ovo e pupa dos predadores Chrysoperla externa e Coleomegilla quadrifasciata. Os ensaios consistiram da aplicação direta dos agrotóxicos sobre ovos e pupas dos predadores e avaliação de efeitos subletais na fertilidade e fecundidade dos adultos emergidos. Para ovos, os produtos fitossanitários foram classificados em função dos efeitos na redução da porcentagem de eclosão de larvas, e para pupas em função do efeito total, conforme a escala de toxicidade proposta pela International Organization for Biological and Integrated Control (IOBC). Todos os produtos fitossanitários (dosagem utilizada) foram inócuos (classe 1) aos ovos de C. externa, entretanto, abamectina (80) e cobre + cálcio (1%) foram considerados levemente nocivos (classe 2) às pupas. Nos bioensaios com C. quadrifasciata, abamectina (80), deltametrina (40) e malationa (150) foram classificados como levemente nocivos (classe 2), enquanto fenitrotiona (100) apresentou-se como moderadamente nocivo (classe 3) aos ovos do predador; para a fase de pupa, abamectina (80), fenitrotiona (100) e malationa (150) foram nocivos (classe 4). Os produtos Azadiractina (1%), clorantraniliprole (14), deltametrina (40), cobre + cálcio (25% + 10%) e enxofre + cálcio (3,5 Ba) são inócuos (classe 1) aos ovos e pupas de C. externa e C. quadrifasciata, e assim devem ser priorizados em pulverizações visando ao controle de pragas no MIP pessegueiro.
Asunto(s)
Agroquímicos/administración & dosificación , Agroquímicos/análisis , Agroquímicos/toxicidad , Escarabajos/crecimiento & desarrollo , Escarabajos/efectos de los fármacos , Control de Plagas/métodos , Insectos/crecimiento & desarrollo , Insectos/efectos de los fármacos , Plagas Agrícolas , Prunus persica/efectos adversosRESUMEN
Euschistus heros (Fabricius) (Hemiptera: Pentatomidae) primarily attack the pods and seeds of soybean plants, causing severe economic losses in Neotropical Region, and chemical control is essential to avoid these losses. Thus, insecticides more effective against this pest and less toxic to Telenomus podisi Ashmead (Hymenoptera: Platygastridae) - the main biological control agent of E. heros - should be used. In this report, we studied the differential acute impacts of pesticides used in Brazilian soybean against E. heros and T. podisi and evaluated their sublethal effects on the parasitoid to identify effective pesticides towards the pest with less harmful effect to the natural enemy. The LC50 of the insecticides to E. heros ranged from 1.20 to 533.74 ng a.i./cm2; the order of toxicity was thiamethoxam + lambda-cyhalothrin > acetamiprid + fenpropathrin > zeta-cypermethrin > acephate > imidacloprid. All pesticides were classified as slightly to moderately toxic to T. podisi based on the risk quotient. The exposure of T. podisi females to imidacloprid and the insecticide pre-formulated mixtures reduced the emergence of the offspring parasitoids by up to 40% whereas zeta-cypermethrin and the insecticides pre-formulated mixtures reduced offspring survival. The preferred order of choice of insecticides for the management of E. heros according to agronomic, toxicological, and environmental feasibility was the following: thiamethoxam + lambda-cyhalothrin > zeta-cypermethrin > acetamiprid + fenpropathrin > acephate > imidacloprid. Our study provides important and pioneer information to select insecticides for effective control of E. heros with lower impacts on T. podisi.
Asunto(s)
Hemípteros/efectos de los fármacos , Himenópteros/efectos de los fármacos , Plaguicidas/toxicidad , Animales , Femenino , Interacciones Huésped-Parásitos , Insecticidas/toxicidad , Masculino , Neonicotinoides/toxicidad , Nitrilos/toxicidad , Nitrocompuestos/toxicidad , Compuestos Organotiofosforados/toxicidad , Fosforamidas/toxicidad , Piretrinas/toxicidad , Tiametoxam/toxicidadRESUMEN
Drosophila suzukii (Matsumura) is an important pest of small fruits, which has been causing significant damage to commercial crops in North America, Europe, and South America. This pest is mainly controlled with insecticide applications because of its highly biotic potential and polyphagy. However, studies conducted in crops infested by D. suzukii have shown that this species is attacked by parasitoids that may serve as effective biological controls for this pest. The aim of the current study is to assess the lethal time (LT10 and LT50) and parasitism potential of exposed adults (F0): sex ratio and longevity (F1) of Trichopria anastrephae Lima and Pachycrepoideus vindemmiae (Rondani) when exposed to dry residues of different commercial insecticides. Abamectin, acetamiprid, thiamethoxam, malathion, phosmet, deltamethrin, spinetoram, and spinosad were evaluated. Pachycrepoideus vindemmiae was more sensitive to insecticides than T. anastrephae, showing higher mortality rates in a shorter period of time, as well as a significant reduction in parasitism. Spinosyns (spinosad and spinetoram) and abamectin caused high P. vindemmiae mortality rates, but were harmless to T. anastrephae. Neonicotinoids, organophosphates, and pyrethroids caused high mortality rates regardless of the species. Treatments did not affect D. suzukii offspring longevity and sex ratio (F1). The current study provides information needed for the implementation of D. suzukii management programs focused on the conservation of natural enemies.
Asunto(s)
Himenópteros , Insecticidas , Animales , Drosophila , Europa (Continente) , Control de Insectos , América del Norte , América del SurRESUMEN
Palpita forficifera Munroe, 1959 (Lepidoptera: Crambidae) is the main pest of the olive tree (Olea europaea L. Oleaceae) in Brazil. This study investigated the biology of P. forficifera reared on different hosts and elaborated the corresponding fertility life table for a better understanding of its development. Biology of P. forficifera was studied using olive cultivars Arbequina, Arbosana and Koroneiki and the alternative host privet (Ligustrum lucidum Ait., Oleaceae), under controlled conditions of temperature (25 ± 2°C), relative humidity (60 ± 10%), and photophase (14 h). We evaluated duration and viability of egg, larva, and pupa stages; number and duration of instars; sex ratio; pupa weight; duration of preoviposition, oviposition, and postoviposition periods; fecundity and longevity. The fertility life table was elaborated from these parameters. Larvae fed with privet had longer larval stage, and consequently, egg-pupa period. Larva viability was lower in cv. Arbosana, which reflected in lower viability in the egg-pupa period. Larvae fed with cv. Koroneiki originated females with higher fecundity. From the joint assessment of the biological parameters and the fertility life tables, cv. Koroneiki provided the greatest population increase, while cv. Arbosana impaired P. forficifera development. Thus, in areas of high occurrence of this species, cv. Arbosana should be considered as the more indicated cultivar for the establishment of new olive groves.
Asunto(s)
Herbivoria , Rasgos de la Historia de Vida , Mariposas Nocturnas/crecimiento & desarrollo , Olea , Animales , Fertilidad , Tablas de Vida , Ligustrum , Especificidad de la EspecieRESUMEN
The ecdysone receptor, naturally activated by steroidal hormones, is a key protein for molting and reproduction processes of insects. Artificial activation of such receptor by specific pesticides induces an anomalous process of ecdysis, causing death of insects by desiccation and starvation. In this paper, we established a protocol for screening agonistic molecules towards ecdysone receptor of insect cells line S2 (Diptera) and Sf9 (Lepidoptera), transfected with the reporter plasmid ere.b.act.luc. Therefore, we set dose-response curves with the ecdysteroid 20-hydroxyecdysone, the phytoecdysteroid ponasterone-A, and tebufenozide, a pesticide belonging to the class of diacylhydrazines. In both cell lines, the median effective concentration values on reporter gene induction (EC50) of ponasterone-A was the smallest, meaning the most active agonist molecule. In Sf9 cells, tebufenozide had as smaller EC50 than 20-hydroxyecdysone, indicating the high agonistic capability and lepidopteran specificity. The protocol established in this study can be useful for a quick screening and rational research of site-specific pesticides.(AU)
O receptor de ecdisona, naturalmente ativado por hormônios esteroidais, é uma proteína-chave nos processos de muda e reprodução de insetos. A ativação artificial desse receptor por meio de pesticidas específicos induz um processo de ecdise anômala, levando o inseto à morte por dessecação e inanição. Neste trabalho, foi estabelecido um protocolo para a triagem de moléculas agonistas em relação ao receptor de ecdisona nas linhagens celulares responsivas S2 (Diptera) e Sf9 (Lepidoptera), transfectadas com o plasmídeo repórter ere.b.act.luc. Para tanto, curvas de dose-resposta foram estabelecidas com o ecdisteroide 20-hidroxiecdisona, o fitoecdisteroide ponasterona-A e tebufenozida, um pesticida pertencente à classe das diacilhidrazinas. Em ambas linhagens celulares, os valores médios de concentração efetiva para indução gênica (EC50) ponasterona-A foram menores, significando que este é o agonista mais potente. Em células Sf9, a tebufenozida apresentou EC50 menor que a 20-hidroxiecdisona, indicando uma alta atividade agonista e especificidade deste inseticida a lepidópteros. O protocolo estabelecido neste trabalho pode ser utilizado para uma rápida triagem e busca racional de pesticidas de alvo bioquímico específico.(AU)
Asunto(s)
Plásmidos , Muda , Insectos , Plaguicidas , EcdisteronaRESUMEN
This work aimed to evaluate the persistence (duration of harmful activity) of five insecticides used for pest control in peach orchards, on larvae and adults of the predator Chrysoperla externa. The insecticides were sprayed on cv. Bordô vine plants using the maximum dosage recommended for peach orchards. Weekly, at 3, 10, 17, 24 and 31 days after spraying, larvae and adults of the predator were exposed to treated leaves in order to assess the residual effect of insecticides on mortality and possible effects on reproduction. Given the toxicity observed along the weekly bioassays, the insecticides were classified into persistence categories established by the International Organization for Biological and Integrated Control of Noxious Animals and Plants (IOBC). High persistence was obtained for the organophosphorus insecticides (% of active ingredient) phosmet (0.100) and malathion (0.200), and both were considered persistent (> 30 days of harmful activity) to larvae and adults of C. externa. Similarly, the benzoylurea insecticide lufenuron (0.005), which acts exclusively on immature stages of insects, was persistent to larvae. Differences concerning the persistence for both development stages evaluated were observed for the pyrethroid insecticide deltamethrin (0.001), that was persistent to larvae but moderately persistent (16 30 days of harmful activity) to adults; and for the organophosphate fenthion (0.050) which was considered moderately persistent to larvae and short-lived (< 5 days of harmful activity) to adults of C. externa.(AU)
Este trabalho teve como objetivo avaliar a persistência (duração da atividade nociva) de cinco inseticidas utilizados no controle de pragas em pessegueiro, em larvas e adultos do predador Chrysoperla externa. Os inseticidas foram pulverizados em plantas de videira cv. Bordô utilizando-se a máxima dosagem recomendada para o pessegueiro. Semanalmente, aos 3, 10, 17, 24 e 31 dias após a pulverização, larvas e adultos do predador foram expostos a folhas pulverizadas para determinação do efeito residual dos inseticidas na mortalidade e possíveis efeitos na reprodução. Em função da toxicidade observada ao longo dos bioensaios semanais, os inseticidas foram classificados conforme a escala de persistência da International Organization for Biological and Integrated Control of Noxious Animals and Plants (IOBC). Alta persistência foi obtida para os inseticidas (% de ingrediente ativo) fosmete (0,100) e malationa (0,200), sendo ambos considerados persistentes (> 30 dias de ação nociva) para larvas e adultos de C. externa. De forma semelhante, o inseticida do grupo das benzoilureias, lufenurom (0,005), que age exclusivamente sobre estágios imaturos de insetos, foi persistente para larvas. Diferenças quanto a persistência para ambos os estágios avaliados foi observada para o inseticida piretroide deltametrina (0,001), que se mostrou persistente para larvas, porém moderadamente persistente (16 30 dias de ação nociva) para adultos; e para o organofosforado fentiona (0,050), que foi considerado moderadamente persistente para larvas e de vida curta (< 5 dias de ação nociva) para adultos de C. externa.(AU)
Asunto(s)
Control de Plagas , Prunus persica , Bioensayo , Control Biológico de Vectores , InsecticidasRESUMEN
The ecdysone receptor, naturally activated by steroidal hormones, is a key protein for molting and reproduction processes of insects. Artificial activation of such receptor by specific pesticides induces an anomalous process of ecdysis, causing death of insects by desiccation and starvation. In this paper, we established a protocol for screening agonistic molecules towards ecdysone receptor of insect cells line S2 (Diptera) and Sf9 (Lepidoptera), transfected with the reporter plasmid ere.b.act.luc. Therefore, we set dose-response curves with the ecdysteroid 20-hydroxyecdysone, the phytoecdysteroid ponasterone-A, and tebufenozide, a pesticide belonging to the class of diacylhydrazines. In both cell lines, the median effective concentration values on reporter gene induction (EC50) of ponasterone-A was the smallest, meaning the most active agonist molecule. In Sf9 cells, tebufenozide had as smaller EC50 than 20-hydroxyecdysone, indicating the high agonistic capability and lepidopteran specificity. The protocol established in this study can be useful for a quick screening and rational research of site-specific pesticides.(AU)
O receptor de ecdisona, naturalmente ativado por hormônios esteroidais, é uma proteína-chave nos processos de muda e reprodução de insetos. A ativação artificial desse receptor por meio de pesticidas específicos induz um processo de ecdise anômala, levando o inseto à morte por dessecação e inanição. Neste trabalho, foi estabelecido um protocolo para a triagem de moléculas agonistas em relação ao receptor de ecdisona nas linhagens celulares responsivas S2 (Diptera) e Sf9 (Lepidoptera), transfectadas com o plasmídeo repórter ere.b.act.luc. Para tanto, curvas de dose-resposta foram estabelecidas com o ecdisteroide 20-hidroxiecdisona, o fitoecdisteroide ponasterona-A e tebufenozida, um pesticida pertencente à classe das diacilhidrazinas. Em ambas linhagens celulares, os valores médios de concentração efetiva para indução gênica (EC50) ponasterona-A foram menores, significando que este é o agonista mais potente. Em células Sf9, a tebufenozida apresentou EC50 menor que a 20-hidroxiecdisona, indicando uma alta atividade agonista e especificidade deste inseticida a lepidópteros. O protocolo estabelecido neste trabalho pode ser utilizado para uma rápida triagem e busca racional de pesticidas de alvo bioquímico específico.(AU)