Exploring chemical diversity in Glycine max cultivars: A multivariate approach in the search for bioactive compounds against Spodoptera cosmioides.

Soybean crop is regulated by abiotic and biotic stresses with great potential in reducing grain yield and quality. The selection of resistant cultivars is a promising approach for mitigating these damages. We evaluated the chemical profile of Glycine max leaves from different cultivars in order to explore their defense mechanisms against Spodoptera cosmioides caterpillars. We optimized solid-liquid extraction techniques using ultrasound bath and static headspace extraction. Additionally, we developed an approach based on liquid and gas chromatography for analyzing the chemical profile of G. max cultivars. The principal component analysis allowed the classification of transgenic cultivars, which are classified as susceptible to S. cosmioides, from those obtained by genetic improvement and resistant to the insect. Differences were observed in the abundance of phenolic glycosides, lipids, aldehydes, and alcohols. More specifically, S. cosmioides resistant cultivars presented molecules related to the jasmonic and salicylic acid pathways. Such data can contribute to a molecular understanding of phenotypic diversity in soybean cultivars, from plant quality to resistance mechanisms and adaptation, to environmental stress and herbivory.

Morphological and chemical plant traits associated with feeding non-preference to adult of Diabrotica speciosa (Coleoptera: Chrysomelidae) in soybean genotypes.

Diabrotica speciosa is an important pest of several crops in South America, including soybeans. Adults cause severe defoliation in soybean plants, and damage is significant when cotyledons are attacked. This study evaluated feeding non-preference to D. speciosa adults using 10 soybean genotypes, testing (i) 15-day-old whole plants and (ii) leaf disks of 60-day-old plants, through assessments of soybean attractiveness and leaf area consumed (LAC). Foliar contents of flavonoids and nutrients, and leaf trichome density were quantified for potential correlations with soybean resistance to adult of D. speciosa. In the whole young-plant experiment, under free-choice conditions, the lowest LAC was observed in IAC 100 and PI 227687. In no-choice, PI 227687 and IGRA RA 626 RR showed lower LAC than the other genotypes. In the leaf disk test, in free-choice, the genotypes IAC 100, PI 274454, PI 227687, DM 339, and BR 16 were the least preferred by adult of D. speciosa. In no-choice, PI 274454 was one of the least preferred, similarly to IGRA RA 626 RR, Dowling, and PI 227687. In the whole plant experiment, a high rutin content and low amounts of zinc, calcium, sulfur and manganese were associated with less consumption of D. speciosa on leaves of resistant genotypes. In contrast, in the leaf disk test there was a significant influence of trichomes in soybean resistance to the pest. In conclusion, the PI lines herein assessed are also promising sources for developing cultivars resistant to D. speciosa.

Oviposition behavior of Helicoverpa armigera in soybean / Comportamento de oviposição de Helicoverpa armigera em soja

The objective of this study was to evaluate the oviposition behavior of Helicoverpa armigera confined in different adult pair density and growth stages of soybean plants, and the resistance of soybean genotypes to H. armigera in the category nonpreference for oviposition. The oviposition behavior of H. armigera was assessed using one, two, and four adult pairs per soybean plant of the cultivar BR-16 at the growth stages: vegetative V8 (eighth unrolled trifoliate leaf), reproductive R2 (full bloom) and reproductive R5.2 (beginning seed). The nonpreference for oviposition was evaluated using eight soybean genotypes and an oviposition preference index was calculated. The number of trichomes in leaflets was quantified for being correlated to H. armigera oviposition. One adult pair and soybean plants stage at pod-set affected and showed the best results oviposition preference on soybean plants. The genotypes M8230-RR and W711-RR presented resistance characteristics, and PI-227687 was preferred for oviposition. The trichome density positively affects the female oviposition behavior.(AU)

O objetivo deste trabalho foi avaliar o comportamento de oviposição de Helicoverpa armigera confinadas em diferentes densidades de casais e estádios fenológicos de plantas de soja, e a resistência de genótipos de soja na categoria não preferência para oviposição para H. armigera. Para o comportamento de oviposição de H. armigera, foram avaliadas as densidades de um, dois e quatro casais por planta, e os estádios fenológicos vegetativo, de florescimento e reprodutivo de plantas de soja do cultivar BR 16. Para o teste de não preferência para oviposição, oito genótipos de soja foram utilizados e um índice de preferência para oviposição foi calculado. A densidade de tricomas nos folíolos foi quantificada para ser correlacionada com a oviposição de H. armigera. A densidade de um casal e plantas de soja em estádio reprodutivo proporcionaram os melhores resultados quanto à preferência para oviposição de H. armigera em soja. Os genótipos M8230 RR e W711 RR apresentaram características de resistência, enquanto o PI 227687 foi o mais preferido para oviposição. A quantidade de tricomas influenciou positivamente no comportamento de oviposição das fêmeas.(AU)

Oviposition behavior of Helicoverpa armigera in soybean / Comportamento de oviposição de Helicoverpa armigera em soja

The objective of this study was to evaluate the oviposition behavior of Helicoverpa armigera confined in different adult pair density and growth stages of soybean plants, and the resistance of soybean genotypes to H. armigera in the category nonpreference for oviposition. The oviposition behavior of H. armigera was assessed using one, two, and four adult pairs per soybean plant of the cultivar BR-16 at the growth stages: vegetative V8 (eighth unrolled trifoliate leaf), reproductive R2 (full bloom) and reproductive R5.2 (beginning seed). The nonpreference for oviposition was evaluated using eight soybean genotypes and an oviposition preference index was calculated. The number of trichomes in leaflets was quantified for being correlated to H. armigera oviposition. One adult pair and soybean plants stage at pod-set affected and showed the best results oviposition preference on soybean plants. The genotypes M8230-RR and W711-RR presented resistance characteristics, and PI-227687 was preferred for oviposition. The trichome density positively affects the female oviposition behavior.(AU)

O objetivo deste trabalho foi avaliar o comportamento de oviposição de Helicoverpa armigera confinadas em diferentes densidades de casais e estádios fenológicos de plantas de soja, e a resistência de genótipos de soja na categoria não preferência para oviposição para H. armigera. Para o comportamento de oviposição de H. armigera, foram avaliadas as densidades de um, dois e quatro casais por planta, e os estádios fenológicos vegetativo, de florescimento e reprodutivo de plantas de soja do cultivar BR 16. Para o teste de não preferência para oviposição, oito genótipos de soja foram utilizados e um índice de preferência para oviposição foi calculado. A densidade de tricomas nos folíolos foi quantificada para ser correlacionada com a oviposição de H. armigera. A densidade de um casal e plantas de soja em estádio reprodutivo proporcionaram os melhores resultados quanto à preferência para oviposição de H. armigera em soja. Os genótipos M8230 RR e W711 RR apresentaram características de resistência, enquanto o PI 227687 foi o mais preferido para oviposição. A quantidade de tricomas influenciou positivamente no comportamento de oviposição das fêmeas.(AU)

Common bean resistance expression to whitefly in winter and rainy seasons in Brazil

Whitefly Bemisia tabaci (Gennadius) biotype B is the major pest of common bean (Phaseolus vulgaris L.) in Brazil and other countries. Host plant resistance is one of the cornerstones of Integrated Pest Management (IPM), and assessment of cultivars for insect resistance is fundamental to provide farmers options for pest control. This study evaluated common bean resistance to whitefly in the winter and rainy seasons in Jaboticabal, Brazil, and correlated the infestation with climatic factors. The plant part and development period of common bean that are more susceptible to whitefly infestation were also examined for potential use in IPM. Field experiments were carried out using 18 and 19 commercial cultivars in the winter and rainy seasons, respectively. Whitefly eggs, nymphs, and adults in the upper part and lower part of plants were sampled from 25 to 60 days after emergence (DAE). Cultivars IAC-Una and IAC-Eldorado had less oviposition and the former also showed lower adult infestation in the winter season. In the rainy season, cultivars IAPAR-81 and Guará had a smaller number of eggs, whereas IAC-Centauro was less infested by nymphs. The number of nymphs and adults was similar among cultivars in the winter and rainy seasons, respectively. The upper part of plants had a greater number of eggs and adults, while, the lower part harbored larger numbers of nymphs. Common bean was more susceptible to whitefly at 25-32 DAE in both seasons. These results add useful information to IPM of whitefly in common bean.(AU)

Common bean resistance expression to whitefly in winter and rainy seasons in Brazil

Whitefly Bemisia tabaci (Gennadius) biotype B is the major pest of common bean (Phaseolus vulgaris L.) in Brazil and other countries. Host plant resistance is one of the cornerstones of Integrated Pest Management (IPM), and assessment of cultivars for insect resistance is fundamental to provide farmers options for pest control. This study evaluated common bean resistance to whitefly in the winter and rainy seasons in Jaboticabal, Brazil, and correlated the infestation with climatic factors. The plant part and development period of common bean that are more susceptible to whitefly infestation were also examined for potential use in IPM. Field experiments were carried out using 18 and 19 commercial cultivars in the winter and rainy seasons, respectively. Whitefly eggs, nymphs, and adults in the upper part and lower part of plants were sampled from 25 to 60 days after emergence (DAE). Cultivars IAC-Una and IAC-Eldorado had less oviposition and the former also showed lower adult infestation in the winter season. In the rainy season, cultivars IAPAR-81 and Guará had a smaller number of eggs, whereas IAC-Centauro was less infested by nymphs. The number of nymphs and adults was similar among cultivars in the winter and rainy seasons, respectively. The upper part of plants had a greater number of eggs and adults, while, the lower part harbored larger numbers of nymphs. Common bean was more susceptible to whitefly at 25-32 DAE in both seasons. These results add useful information to IPM of whitefly in common bean.

Oviposition Preference and Antibiosis to Spodoptera frugiperda (Lepidoptera: Noctuidae) in Brazilian Maize Landraces.

Spodoptera frugiperda (J.E. Smith) is a major pest of maize [Zea mays L. (Poales: Poaceae)] in tropical and subtropical regions. We aimed to evaluate the oviposition preference, growth, and survival of S. frugiperda on maize landraces and assess the nutritional quality of the leaves of different Brazilian maize landraces through evaluation of consumption indices. The oviposition preference was assayed using free and no-choice tests, and antibiosis by evaluating insect growth parameters, including weight, development time, survival in different stages of the life cycle, and nutritional indices. Landrace Pérola and cultivar BRS-Caatingueiro were the least preferred for S. frugiperda oviposition. Larvae fed with landrace Pérola consumed a lower amount of leaves and showed longer development time and lower survival until the end of the pupal stage. Larvae fed with the leaves of landrace Pérola and cultivar BRS-Caatingueiro displayed the lowest nutritional indices. Overall, Pérola was the most promising source of resistance to S. frugiperda. Identification of resistance in maize landraces may support breeding programs aimed at developing cultivars and hybrids resistant to S. frugiperda and other agricultural pests and inform growers regarding resistance of their landraces for integrated pest management.

Spodoptera albula susceptibility to Bacillus thuringiensis-based biopesticides.

Single concentration and virulence (mean lethal concentration) bioassays were performed to evaluate the susceptibility of S. albula second instar larvae to seven Bacillus thuringiensis-based biopesticides. Bioassays were conducted using three replicates and repeated three times at 25 °C, 70 ±â€¯10% RH, and a 12:12 (light/dark) photoperiod; mortality was recorded seven days after treatment. The results were subjected to a Tukey's test and Probit analysis. Agree, DiPel SC, and XenTari achieved mortality rates of up to 80%, with the first of these being the most virulent against S. albula. Different Dipel formulations showed different degrees of larvicidal activity.

Attractiveness, non-preference for feeding and oviposition to Ascia monuste orseis Godart (Lepidoptera: Pieridae) in collard greens / Atratividade, não-preferência para alimentação e oviposição de Ascia monuste orseis Godart (Lepidoptera: Pieridae) em couve comum

Collard greens Brassica oleracea var. acephala is one of the most important horticultural grown in Brazil for human feeding. The caterpillar Ascia monuste orseis (Lepidoptera: Pieridae) stands out among the important pest in Brassicaceae causing severe plant defoliation. The objective of this study was to identify resistant genotypes (antixenosis) in 26 collard greens genotypes to A. monuste orseis. In free-choice test, randomized blocks were used; and in the non-choice test we adopted a completely randomized design. Manteiga de Jundiaí, crespa de Capão Bonito, couve de Arthur Nogueira 1, manteiga I-1811, manteiga de Ribeirão Pires I-1811, orelha-de-elefante and Pires 1 de Campinas presented antixenosis (non-preference for oviposition). Pires 1 de Campinas, manteiga I-1811, manteiga de São José, verde-escura and manteiga de Monte Alegre presented antixenosis (non-preference for feeding). These collard greens genotypes can be directly used by farmers for cultivation or by breeders as donor sources in breeding programs for resistance to A. monuste orseis.(AU)

Brassica oleracea var. acephala (couve comum) é uma das mais importantes olerícolas cultivadas no Brasil para alimentação humana. A lagarta Ascia monuste orseis (Lepidoptera: Pieridae) destaca-se entre as pragas mais significativas no cultivo de Brassicaceae por causar severa desfolha na planta. O objetivo deste trabalho foi identificar, em 26 genótipos de couve comum, fontes de resistência (antixenose) a A. monuste orseis. No teste de livre escolha, adotou-se o esquema casualizado de blocos; e no teste sem chance de escolha o esquema foi inteiramente casualizado. Manteiga de Jundiaí, crespa de Capão Bonito, couve de Arthur Nogueira 1, manteiga I-1811, manteiga de Ribeirão Pires I-1811, orelha-de-elefante e Pires 1 de Campinas apresentaram antixenose (não preferência para oviposição). Pires 1 de Campinas, manteiga I-1811, manteiga de São José, verde-escura e manteiga de Monte Alegre apresentaram antixenose (não preferência para alimentação). Esses genótipos de couve comum podem ser cultivados diretamente por agricultores ou ser usados por melhoristas em programas de melhoramento genético para resistência a A. monuste orseis.(AU)

Attractiveness, non-preference for feeding and oviposition to Ascia monuste orseis Godart (Lepidoptera: Pieridae) in collard greens / Atratividade, não-preferência para alimentação e oviposição de Ascia monuste orseis Godart (Lepidoptera: Pieridae) em couve comum

Collard greens Brassica oleracea var. acephala is one of the most important horticultural grown in Brazil for human feeding. The caterpillar Ascia monuste orseis (Lepidoptera: Pieridae) stands out among the important pest in Brassicaceae causing severe plant defoliation. The objective of this study was to identify resistant genotypes (antixenosis) in 26 collard greens genotypes to A. monuste orseis. In free-choice test, randomized blocks were used; and in the non-choice test we adopted a completely randomized design. Manteiga de Jundiaí, crespa de Capão Bonito, couve de Arthur Nogueira 1, manteiga I-1811, manteiga de Ribeirão Pires I-1811, orelha-de-elefante and Pires 1 de Campinas presented antixenosis (non-preference for oviposition). Pires 1 de Campinas, manteiga I-1811, manteiga de São José, verde-escura and manteiga de Monte Alegre presented antixenosis (non-preference for feeding). These collard greens genotypes can be directly used by farmers for cultivation or by breeders as donor sources in breeding programs for resistance to A. monuste orseis.(AU)

Brassica oleracea var. acephala (couve comum) é uma das mais importantes olerícolas cultivadas no Brasil para alimentação humana. A lagarta Ascia monuste orseis (Lepidoptera: Pieridae) destaca-se entre as pragas mais significativas no cultivo de Brassicaceae por causar severa desfolha na planta. O objetivo deste trabalho foi identificar, em 26 genótipos de couve comum, fontes de resistência (antixenose) a A. monuste orseis. No teste de livre escolha, adotou-se o esquema casualizado de blocos; e no teste sem chance de escolha o esquema foi inteiramente casualizado. Manteiga de Jundiaí, crespa de Capão Bonito, couve de Arthur Nogueira 1, manteiga I-1811, manteiga de Ribeirão Pires I-1811, orelha-de-elefante e Pires 1 de Campinas apresentaram antixenose (não preferência para oviposição). Pires 1 de Campinas, manteiga I-1811, manteiga de São José, verde-escura e manteiga de Monte Alegre apresentaram antixenose (não preferência para alimentação). Esses genótipos de couve comum podem ser cultivados diretamente por agricultores ou ser usados por melhoristas em programas de melhoramento genético para resistência a A. monuste orseis.(AU)

Resistance in cowpea cultivars to Bruchidius atrolineatus (PIC) (Coleoptera: Chrysomelidae: Bruchinae) / Resistência em cultivares de feijão-caupi a Bruchidius atrolineatus (Pic) (Coleoptera: Chrysomelidae: Bruchinae)

This study aimed to assess the resistance in cowpea cultivars to Bruchidius atrolineatus (Pic) attack. The experiment was conducted at the Faculdade de Ciências Agrárias e Veterinárias of Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Jaboticabal (SP). The following cultivars were used: BR17 Gurgueia, BR3 Tracuateua, BRS Novaera, Sempre Verde, BRS Milênio, and BRS Urubuquara. The non-preference test without choice evaluated the number of viable eggs, unviable and total posed by insects in grains, after 25 days of confinement. In addition, it was observed, in a daily basis, the total dry matter consumed and dry matter consumed per insect; male and female mass; male, female and total egg-adult cycle length; male and female longevity; sex ratio; number of emerged insects and percentage of emerged insects. The non-preference test with free choice evaluated the number of viable, unviable and total eggs and adult attractiveness after 24 hours and seven days of release. Sempre Verde cultivar was the least preferred for oviposition in the test without choice and showed lower number and percentage of emerged insects. BRS Milênio had the lowest total dry mass consumed and dry mass consumed per insect.(AU)

O objetivo do presente trabalho foi avaliar a resistên cia em cultivares de feijãocaupi ao ataque de Bruchidius atrolineatus (Pic). O experimento foi conduzido na Faculdade de Ciências Agrárias da Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), campus de Jaboticabal/SP. Seis cultivares foram utilizados: BR17 Gurgueia, BR3 Tracuateua, BRS Novaera, Sempre Verde, BRS Milênio e BRS Urubuquara. No teste de não preferência sem chance de escolha, foram feitas as avaliações do número de ovos viáveis, inviáveis e totais colocados pelos insetos nos grãos, após 25 dias de confinamento. Nas amostras foram observadas também, diariamente, a massa seca consumida e a massa seca consumida por inseto; a massa de machos e fêmeas; o período de ovo adulto de fêmeas, machos e total; a longevidade de machos e fêmeas; a razão sexual; e a porcentagem de insetos emergidos. No teste com chance de escolha foram realizadas as contagens de ovos viáveis, inviáveis e totais e avaliada a atratividade dos adultos após 24 horas e sete dias da liberação. O cultivar Sempre Verde foi o menos preferido para oviposição, em teste sem chance de escolha, e apresentou menor número e porcentagem de insetos emergidos. Já BRS Milênio teve a menor massa seca consumida total e por inseto.(AU)

Resistance in cowpea cultivars to Bruchidius atrolineatus (PIC) (Coleoptera: Chrysomelidae: Bruchinae) / Resistência em cultivares de feijão-caupi a Bruchidius atrolineatus (Pic) (Coleoptera: Chrysomelidae: Bruchinae)

This study aimed to assess the resistance in cowpea cultivars to Bruchidius atrolineatus (Pic) attack. The experiment was conducted at the Faculdade de Ciências Agrárias e Veterinárias of Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Jaboticabal (SP). The following cultivars were used: BR17 Gurgueia, BR3 Tracuateua, BRS Novaera, Sempre Verde, BRS Milênio, and BRS Urubuquara. The non-preference test without choice evaluated the number of viable eggs, unviable and total posed by insects in grains, after 25 days of confinement. In addition, it was observed, in a daily basis, the total dry matter consumed and dry matter consumed per insect; male and female mass; male, female and total egg-adult cycle length; male and female longevity; sex ratio; number of emerged insects and percentage of emerged insects. The non-preference test with free choice evaluated the number of viable, unviable and total eggs and adult attractiveness after 24 hours and seven days of release. Sempre Verde cultivar was the least preferred for oviposition in the test without choice and showed lower number and percentage of emerged insects. BRS Milênio had the lowest total dry mass consumed and dry mass consumed per insect.

O objetivo do presente trabalho foi avaliar a resistên cia em cultivares de feijãocaupi ao ataque de Bruchidius atrolineatus (Pic). O experimento foi conduzido na Faculdade de Ciências Agrárias da Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), campus de Jaboticabal/SP. Seis cultivares foram utilizados: BR17 Gurgueia, BR3 Tracuateua, BRS Novaera, Sempre Verde, BRS Milênio e BRS Urubuquara. No teste de não preferência sem chance de escolha, foram feitas as avaliações do número de ovos viáveis, inviáveis e totais colocados pelos insetos nos grãos, após 25 dias de confinamento. Nas amostras foram observadas também, diariamente, a massa seca consumida e a massa seca consumida por inseto; a massa de machos e fêmeas; o período de ovo adulto de fêmeas, machos e total; a longevidade de machos e fêmeas; a razão sexual; e a porcentagem de insetos emergidos. No teste com chance de escolha foram realizadas as contagens de ovos viáveis, inviáveis e totais e avaliada a atratividade dos adultos após 24 horas e sete dias da liberação. O cultivar Sempre Verde foi o menos preferido para oviposição, em teste sem chance de escolha, e apresentou menor número e porcentagem de insetos emergidos. Já BRS Milênio teve a menor massa seca consumida total e por inseto.

Resistance in cowpea cultivars to Bruchidius atrolineatus (PIC) (Coleoptera: Chrysomelidae: Bruchinae) / Resistência em cultivares de feijão-caupi a Bruchidius atrolineatus (Pic) (Coleoptera: Chrysomelidae: Bruchinae)

This study aimed to assess the resistance in cowpea cultivars to Bruchidius atrolineatus (Pic) attack. The experiment was conducted at the Faculdade de Ciências Agrárias e Veterinárias of Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Jaboticabal (SP). The following cultivars were used: BR17 Gurgueia, BR3 Tracuateua, BRS Novaera, Sempre Verde, BRS Milênio, and BRS Urubuquara. The non-preference test without choice evaluated the number of viable eggs, unviable and total posed by insects in grains, after 25 days of confinement. In addition, it was observed, in a daily basis, the total dry matter consumed and dry matter consumed per insect; male and female mass; male, female and total egg-adult cycle length; male and female longevity; sex ratio; number of emerged insects and percentage of emerged insects. The non-preference test with free choice evaluated the number of viable, unviable and total eggs and adult attractiveness after 24 hours and seven days of release. Sempre Verde cultivar was the least preferred for oviposition in the test without choice and showed lower number and percentage of emerged insects. BRS Milênio had the lowest total dry mass consumed and dry mass consumed per insect.(AU)

O objetivo do presente trabalho foi avaliar a resistência em cultivares de feijão-caupi ao ataque de Bruchidius atrolineatus (Pic). O experimento foi conduzido na Faculdade de Ciências Agrárias da Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), campus de Jaboticabal/SP. Seis cultivares foram utilizados: BR17 Gurgueia, BR3 Tracuateua, BRS Novaera, Sempre Verde, BRS Milênio e BRS Urubuquara. No teste de não preferência sem chance de escolha, foram feitas as avaliações do número de ovos viáveis, inviáveis e totais colocados pelos insetos nos grãos, após 25 dias de confinamento. Nas amostras foram observadas também, diariamente, a massa seca consumida e a massa seca consumida por inseto; a massa de machos e fêmeas; o período de ovo adulto de fêmeas, machos e total; a longevidade de machos e fêmeas; a razão sexual; e a porcentagem de insetos emergidos. No teste com chance de escolha foram realizadas as contagens de ovos viáveis, inviáveis e totais e avaliada a atratividade dos adultos após 24 horas e sete dias da liberação. O cultivar Sempre Verde foi o menos preferido para oviposição, em teste sem chance de escolha, e apresentou menor número e porcentagem de insetos emergidos. Já BRS Milênio teve a menor massa seca consumida total e por inseto.(AU)

Factors Influencing Expression of Antixenosis in Soybean to Anticarsia gemmatalis and Spodoptera frugiperda (Lepidoptera: Noctuidae).

This study aimed to evaluate some factors that influence the expression of antixenosis in soybean genotypes against Anticarsia gemmatalis Hübner and Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae). Free-choice and no-choice feeding assays were performed with the resistant soybean genotype IAC 100 and the susceptible genotype BRSGO 8360 using A. gemmatalis and S. frugiperda larvae. The following factors that may affect expression of resistance were evaluated: one larva versus two larvae per leaf disc; use of larvae without prior feeding suspension versus larvae starved for 3 h prior to the assay; leaf discs versus entire leaflets; upper part versus lower part of the plant; and, vegetative versus reproductive growth stages. The level of resistance exhibited by the genotype IAC 100 was high enough to not be obscured by the effects of all factors assayed in the present study upon the feeding preference of A. gemmatalis and S. frugiperda larvae. However, our results demonstrate the importance of knowing the optimal conditions for conducting an assay for evaluating resistance of genotypes for specialist and generalist insect species. Utilization of two larvae of A. gemmatalis per leaf disc, not starved before the assays, with leaf discs from the upper part of plants at the reproductive growth stage provided better discrimination of differences in antixenosis expression in soybean genotypes. For S. frugiperda, use of one larva per leaf disc, not starved before the assays, with leaf discs from the lower part of plants at the reproductive growth stage gave more satisfactory results for feeding preference tests.

Infestation of Caliothrips phaseoli (Thysanoptera: Thripidae) on Bean Cultivars Grown in the Winter, Rainy, and Dry Seasons in Brazil.

The present study aimed to identify common bean (Phaseolus vulgaris L.) cultivars less susceptible to Caliothrips phaseoli (Hood) in different growing seasons, to evaluate whether climatic conditions influence plant resistance to C. phaseoli infestation, and to investigate the preferred plant part for insect feeding. Eighteen common bean cultivars were evaluated in the winter season, and 19 cultivars were assessed in the rainy and dry seasons, under field conditions in the municipality of Jaboticabal, state of São Paulo, Brazil. Infestation of C. phaseoli nymphs in the upper and lower parts of the beans plants was recorded at weekly intervals from 25 days after plant emergence (DAE) to 60 DAE. In the winter season, the cultivars 'IAC Galante,' 'IAC Centauro,' 'IAC Carioca Eté,' and 'IAC Formoso' had significantly lower number of thrips than the cultivar 'IAC Diplomata.' In the rainy season, the cultivars 'IAC Harmonia' and 'IPR Siriri' had the lowest thrips infestation, differing from the cultivars 'BRS Pontal' and 'IAC Una.' The bean cultivars were equally susceptible to C. phaseoli in the dry season. The results suggest that C. phaseoli nymphs prefer to infest leaves of the lower part of bean plants, like most generalist herbivorous insects. In the winter and dry seasons, the highest thrips infestation was observed at 60 DAE, while in the rainy season, it was recorded from 32 to 46 DAE. Overall, C. phaseoli infestation on bean cultivars was not influenced by either temperature, relative humidity, or rainfall.

Determinação dos tipos de resistência a Spodoptera cosmioides (Walker) (Lepidoptera: Noctuidae) em genótipos de soja / Determination of the resistance types to Spodoptera cosmioides (Walker) (Lepidoptera: Noctuidae) in soybean genotypes

O objetivo do presente trabalho foi avaliar os tipos de resistência de genótipos de soja a Spodoptera cosmioides (Walker) em laboratório. Os genótipos de soja testados foram: IAC 100 (padrão resistente), BR16 (padrão suscetível), Dowling, PI 227687, PI 274454, IGRA RA 626 RR, PI 227682, BRSGO 8360, IGRA RA 516 RR e P 98Y11 RR. Foram realizados testes de não preferência para alimentação com e sem chance de escolha utilizando-se duas lagartas recém-eclodidas por genótipo ou uma lagarta de 3º instar por genótipo em ambos os testes. Avaliou-se a atratividade das lagartas em diferentes intervalos de tempo, e ao término dos experimentos, quantificou-se a área foliar consumida. No teste de antibiose, lagartas recém-eclodidas foram individualizadas em placas de Petri, onde foram fornecidos folíolos dos genótipos durante toda a fase larval, e os seguintes parâmetros biológicos foram avaliados: período e viabilidade de larvas, pupas e total (larvas + pupas), peso de lagartas e de pupas, razão sexual e longevidade dos adultos. Em geral, nos testes de preferência para alimentação, não se verificaram diferenças significativas no consumo foliar entre os genótipos. No ensaio de antibiose, os genótipos PI 227687, PI 227682 e IAC 100 proporcionaram 100% de mortalidade larval e os menores pesos de lagartas, variando entre 37,65 a 85,56 mg. Os genótipos de soja testados não...(AU)

The aim of this work was to evaluate the resistance types in soybean genotypes to Spodoptera cosmioides (Walker) in laboratory. Soybean genotypes assessed were as follows: IAC 100 (resistance standard), BR16 (susceptible standard), Dowling, PI 227687, PI 274454, IGRA RA 626 RR, PI 227682, BRSGO 8360, IGRA RA 516 RR and P 98Y11 RR. Free-choice and no-choice feeding non-preference tests were done using two newly-hatched larvae per genotype or one third-instar larva per genotype in both tests. Larvae attractiveness was evaluated in different times, and at the end of the experiments the leaf area consumed was quantified. In the antibiosis test, newly-hatched larvae were individualized into Petri dishes, where leaflets of the genotypes were offered over the larval stage, and the following biological parameters were assessed: period and viability of larvae, pupae and overall (larvae + pupae), weight of larvae and pupae, sex ratio and adults longevity. Overall, in the feeding preference tests, significant differences were not found in leaf consumption among the genotypes. In the antibiosis assay, genotypes PI 227687, PI 227682 and IAC 100 caused 100% larval mortality and the lowest weight of larvae, ranging between 37.65 and 85.56 mg. All soybean genotypes evaluated do not exhibit feeding non-preference type resistance to S. cosmioides, and PI 227687, PI 227682 and...(AU)

Não preferência para alimentação e antibiose em cultivares de amendoim a Stegasta bosquella (Chambers) (Lepidoptera: Gelechiidae) / Non-preference for feeding and antibiosis in peanut cultivars to Stegasta bosquella (Chambers) (Lepidoptera: Gelechiidae)

Este trabalho teve como objetivos avaliar a atratividade, não preferência para alimentação e antibiose em cultivares de amendoim de hábitos de crescimento ereto e rasteiro a Stegasta bosquella (Chambers). Avaliaram-se oito cultivares, sendo quatro de hábito de crescimento ereto (IAC Tatu, IAC 22, IAC 8112 e IAC 5) e quatro de hábito rasteiro (IAC Runner 886, IAC 147, IAC 125 e IAC 503). Foram realizados testes de não preferência para alimentação com e sem chance de escolha, utilizando-separes de discos foliares sobrepostos de 1,0 cm de diâmetro, os quais foram dispostos em placas de Petri onde foram liberadas lagartas de terceiro instar de S. bosquella. Avaliou-se a atratividade das lagartas em tempos pré-estabelecidos, além da massa seca consumida. No teste de antibiose, foram avaliados os parâmetros biológicos: período e viabilidade larval, de pré-pupa, pupal e total, pesos de lagartas e pupas, razão sexual e longevidade. Nenhuma das cultivares de amendoim de hábito de crescimento rasteiro apresentaram resistência do tipo não preferência para alimentação. Dentre as cultivares de hábito de crescimento ereto, IAC 5 e IAC 22 foram as menos atrativas e consumidas no teste de não preferência para alimentação com chance de escolha, e IAC 5 e IAC 8112 foram as menos atrativas no teste sem chance de escolha. As cultivares de hábito rasteiro IAC 147 e IAC Runner 886 afetaram a...(AU)

This work aimed to evaluate the attractiveness, non-preference for feeding and antibiosis in straight and runner growth habit peanut cultivars to Stegasta bosquella (Chambers). Eight cultivars were evaluated, four of straight growth habit (IAC Tatu, IAC 22, IAC 8112 and IAC 5) and four of runner growth habit (IAC Runner 886, IAC 147, IAC 125 and IAC 503). Free-choice and no-choice feeding tests were performed, using pairs of overlapped leaf discs with 1.0 cm diameter, which were placed in Petri dishes where third instar larvae of S. bosquella were released. The attractiveness to the larvae was assessed in predetermined times, in addition to the dry mass consumed. In the antibiosis assay, the biological parameters were evaluated: period and viability of larvae, pre-pupae, pupae, and total, weight of larvae and pupae, sex ratio and longevity. None of the runner growth habit cultivars exhibited non-preference for feeding-type resistance. Among the straight growth habit cultivars, IAC 5 and IAC 22 were the least attractive and consumed in the free-choice feeding test, and IAC 5 and IAC 8112 were the least attractive in the no-choice test. The runner growth habit cultivars IAC 147 and IAC Runner 886 affected the larval survival of S. bosquella, exhibiting antibiosis-type resistance. For the straight growth habit cultivars, IAC 22 and IAC 8112 affected the larval viability...(AU)

 

Determinação dos tipos de resistência a Spodoptera cosmioides (Walker) (Lepidoptera: Noctuidae) em genótipos de soja / Determination of the resistance types to Spodoptera cosmioides (Walker) (Lepidoptera: Noctuidae) in soybean genotypes

O objetivo do presente trabalho foi avaliar os tipos de resistência de genótipos de soja a Spodoptera cosmioides (Walker) em laboratório. Os genótipos de soja testados foram: IAC 100 (padrão resistente), BR16 (padrão suscetível), Dowling, PI 227687, PI 274454, IGRA RA 626 RR, PI 227682, BRSGO 8360, IGRA RA 516 RR e P 98Y11 RR. Foram realizados testes de não preferência para alimentação com e sem chance de escolha utilizando-se duas lagartas recém-eclodidas por genótipo ou uma lagarta de 3º instar por genótipo em ambos os testes. Avaliou-se a atratividade das lagartas em diferentes intervalos de tempo, e ao término dos experimentos, quantificou-se a área foliar consumida. No teste de antibiose, lagartas recém-eclodidas foram individualizadas em placas de Petri, onde foram fornecidos folíolos dos genótipos durante toda a fase larval, e os seguintes parâmetros biológicos foram avaliados: período e viabilidade de larvas, pupas e total (larvas + pupas), peso de lagartas e de pupas, razão sexual e longevidade dos adultos. Em geral, nos testes de preferência para alimentação, não se verificaram diferenças significativas no consumo foliar entre os genótipos. No ensaio de antibiose, os genótipos PI 227687, PI 227682 e IAC 100 proporcionaram 100% de mortalidade larval e os menores pesos de lagartas, variando entre 37,65 a 85,56 mg. Os genótipos de soja testados não...

The aim of this work was to evaluate the resistance types in soybean genotypes to Spodoptera cosmioides (Walker) in laboratory. Soybean genotypes assessed were as follows: IAC 100 (resistance standard), BR16 (susceptible standard), Dowling, PI 227687, PI 274454, IGRA RA 626 RR, PI 227682, BRSGO 8360, IGRA RA 516 RR and P 98Y11 RR. Free-choice and no-choice feeding non-preference tests were done using two newly-hatched larvae per genotype or one third-instar larva per genotype in both tests. Larvae attractiveness was evaluated in different times, and at the end of the experiments the leaf area consumed was quantified. In the antibiosis test, newly-hatched larvae were individualized into Petri dishes, where leaflets of the genotypes were offered over the larval stage, and the following biological parameters were assessed: period and viability of larvae, pupae and overall (larvae + pupae), weight of larvae and pupae, sex ratio and adults longevity. Overall, in the feeding preference tests, significant differences were not found in leaf consumption among the genotypes. In the antibiosis assay, genotypes PI 227687, PI 227682 and IAC 100 caused 100% larval mortality and the lowest weight of larvae, ranging between 37.65 and 85.56 mg. All soybean genotypes evaluated do not exhibit feeding non-preference type resistance to S. cosmioides, and PI 227687, PI 227682 and...

Não preferência para alimentação e antibiose em cultivares de amendoim a Stegasta bosquella (Chambers) (Lepidoptera: Gelechiidae) / Non-preference for feeding and antibiosis in peanut cultivars to Stegasta bosquella (Chambers) (Lepidoptera: Gelechiidae)

Este trabalho teve como objetivos avaliar a atratividade, não preferência para alimentação e antibiose em cultivares de amendoim de hábitos de crescimento ereto e rasteiro a Stegasta bosquella (Chambers). Avaliaram-se oito cultivares, sendo quatro de hábito de crescimento ereto (IAC Tatu, IAC 22, IAC 8112 e IAC 5) e quatro de hábito rasteiro (IAC Runner 886, IAC 147, IAC 125 e IAC 503). Foram realizados testes de não preferência para alimentação com e sem chance de escolha, utilizando-separes de discos foliares sobrepostos de 1,0 cm de diâmetro, os quais foram dispostos em placas de Petri onde foram liberadas lagartas de terceiro instar de S. bosquella. Avaliou-se a atratividade das lagartas em tempos pré-estabelecidos, além da massa seca consumida. No teste de antibiose, foram avaliados os parâmetros biológicos: período e viabilidade larval, de pré-pupa, pupal e total, pesos de lagartas e pupas, razão sexual e longevidade. Nenhuma das cultivares de amendoim de hábito de crescimento rasteiro apresentaram resistência do tipo não preferência para alimentação. Dentre as cultivares de hábito de crescimento ereto, IAC 5 e IAC 22 foram as menos atrativas e consumidas no teste de não preferência para alimentação com chance de escolha, e IAC 5 e IAC 8112 foram as menos atrativas no teste sem chance de escolha. As cultivares de hábito rasteiro IAC 147 e IAC Runner 886 afetaram a...

This work aimed to evaluate the attractiveness, non-preference for feeding and antibiosis in straight and runner growth habit peanut cultivars to Stegasta bosquella (Chambers). Eight cultivars were evaluated, four of straight growth habit (IAC Tatu, IAC 22, IAC 8112 and IAC 5) and four of runner growth habit (IAC Runner 886, IAC 147, IAC 125 and IAC 503). Free-choice and no-choice feeding tests were performed, using pairs of overlapped leaf discs with 1.0 cm diameter, which were placed in Petri dishes where third instar larvae of S. bosquella were released. The attractiveness to the larvae was assessed in predetermined times, in addition to the dry mass consumed. In the antibiosis assay, the biological parameters were evaluated: period and viability of larvae, pre-pupae, pupae, and total, weight of larvae and pupae, sex ratio and longevity. None of the runner growth habit cultivars exhibited non-preference for feeding-type resistance. Among the straight growth habit cultivars, IAC 5 and IAC 22 were the least attractive and consumed in the free-choice feeding test, and IAC 5 and IAC 8112 were the least attractive in the no-choice test. The runner growth habit cultivars IAC 147 and IAC Runner 886 affected the larval survival of S. bosquella, exhibiting antibiosis-type resistance. For the straight growth habit cultivars, IAC 22 and IAC 8112 affected the larval viability...

Antibiose e não preferência para oviposição de Bemisia tabaci (Genn) biótipo B (Hemiptera: Aleyrodidae) em genótipos de feijoeiro comum / Antibiosis and non preference for the oviposition of Bemisia tabaci (Genn) biotype B (Hemiptera: Aleyrodidae) in common bean genotypes

O feijoeiro comum, Phaseolus vulgaris L., constitui importante fonte de proteína e renda para muitos países, entre eles, o Brasil. Diferentes fatores contribuem para a redução da produção, como os insetos pragas, destacando-se Bemisia tabaci (Genn.) biótipo B. O presente trabalho teve por objetivo identificar genótipos de feijoeiro comum resistentes à B. tabaci biótipo B e os tipos de resistência envolvidos. Para isso, foram realizados dois experimentos desenvolvidos em laboratório e em casa-de-vegetação, avaliando-se 11 genótipos de feijoeiro comum. Para o teste com chance de escolha, o delineamento utilizado foi o de blocos casualizados, e para os testes sem chance de escolha e antibiose, a escolha foi pelo inteiramente casualizado, totalizando seis repetições para cada teste. As variáveis avaliadas foram: período de incubação dos ovos; período ninfal; período de ovo a adulto; viabilidade de ovo a adulto e longevidade de adultos. O genótipo IAC-Harmonia prolongou os períodos ninfal e de ovo a adulto de B. tabaci biótipo B. Os genótipos testados foram igualmente ovipositados pela mosca-branca, em testes com e sem chance de escolha.(AU)

The common bean Phaseolus vulgaris L. constitutes an important source of protein and income for many countries, including Brazil. Different factors contribute with the reduction in production, including pest insects, especially Bemisia tabaci (Genn.) biotype B. This study aimed to identify common bean genotypes resistant to B. tabaci biotype B and the types of resistance involved. Therefore, two experiments were developed in a greenhouse and laboratory, evaluating 11 common bean genotypes. To test the free-choice experimental design, the randomized block design was adopted, and the completely randomized one was selected for the no-choice tests and antibiosis, with six replications for each test. The following variables were evaluated: incubation period of eggs; nymphal; egg to adult; viability of egg to adult and adult longevity. The IAC-Harmony prolonged the nymphal and egg to adult periods of B. tabaci biotype B. The genotypes were also tested by the whitefly oviposition in free and no choice tests.(AU)