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 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)

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.

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)

Development of a new method to prepare nano-/microparticles loaded with extracts of Azadirachta indica, their characterization and use in controlling Plutella xylostella.

Biodegradable nanoparticles have been widely explored as carriers for controlled delivery of therapeutic molecules; however, studies describing the development of nanoparticles as carriers for biopesticide products are few. In this work, a new method to prepare nanoparticles loaded with neem (Azadirachta indica) extracts is presented. In this study, nanoparticles were formulated as colloidal suspension and (spray-dried) powder and characterized by evaluating pH, particle size, zeta potential, morphology, absolute recovery, and entrapment efficiency. A high-performance liquid chromatography method was used for nanoparticle characterization. The best formulations presented absolute recovery and entrapment efficiencies of approximately 100% and a release profile based on swelling and relaxation of the polymer or polymer erosion. The biological data of the formulated products against Plutella xylostella showed 100% larval mortality. The nanoparticle information improved the stability of neem products against ultraviolet radiation and increased their dispersion in the aqueous phase.

Efeito de cultivares de repolho e doses de extrato aquoso de nim na alimentação e biologia de Plutella xylostella (Linnaeus) (Lepidoptera: plutellidae) / Effect of cabbage cultivars and doses of aqueous extrat of neem on feeding and biology of Plutella xylostella (linnaeus) (lepidoptera: plutellidae)

Avaliaram-se os efeitos isolados e associados das cultivares de repolho Ruby Ball e Chato de Quintal e o extrato aquoso de amêndoas de frutos de nim (Azadirachta indica A. Juss.) nas concentrações de 5 e 10% sobre a atratividade, alimentação e desenvolvimento de Plutella xylostella (L.). No teste de não preferência para alimentação com chance de escolha, discos foliares de cada tratamento foram dispostos em placas de Petri onde foram liberadas três lagartas/tratamento, enquanto no teste sem chance de escolha duas lagartas foram colocadas em placas de Petri contendo um disco foliar em cada placa. No teste de biologia, lagartas recém-eclodidas foram transferidas para placas de Petri, na proporção de uma por placa, onde foram avaliados os parâmetros biológicos: mortalidade larval após 1, 3 e 5 dias; mortalidade pupal; mortalidade total; peso de lagartas com seis dias de idade; peso de pupas com 24 horas de idade; e longevidade de adultos. A cultivar Ruby Ball apresentou menor atratividade às lagartas no teste com chance de escolha. O extrato de nim em ambas as concentrações foi considerado repelente no teste com chance de escolha. Não houve diferença na massa foliar seca consumida pelas larvas, nos testes com e sem chance de escolha. Também não foi observada diferença na mortalidade larval, pupal e total entre as cultivares. Ambas as doses do extrato de nim foram igualmente eficientes na mortalidade da traça-das-crucíferas. Não houve diferença do peso de lagartas e pupas e da longevidade dos adultos de P. xylostella entre as cultivares.

The isolated and associated effects of cabbage cultivars Ruby Ball and Chato de Quintal and aqueous extract of seeds of fruits of neem (Azadirachta indica A. Juss.) were evaluated in the concentrations of 5 and 10% on Plutella xylostella (L.) attractiveness, feeding and development. In free-choice no-preference for feeding test, leaf discs of each treatment were placed in Petri dishes where three caterpillars/treatment were released while in no-choice test two caterpillars were placed in Petri dishes with one leaf disc in each dish. In the biology test, neonate larvae were transferred to Petri dishes in the proportion of one per dish, whereas the biological parameters were evaluated: larvae mortality after 1, 3 and 5 days; pupae mortality; total mortality; six day-old larvae weight; 24 hour-old pupae; and adult longevity. Cultivar Ruby Ball showed lower attractiveness to the caterpillars in free-choice test. Neem extract in both concentrations was repellent to the caterpillars in free-choice test. There were no differences in the dry mass consumed by the caterpillars in free-choice and no-choice tests. There were no differences in larval, pupal and total mortality between the cultivars. Both doses of neem extract were equally efficient in the mortality of the diamondback moth. There were no differences in caterpillars and pupae weight and in the longevity of the adults of P. xyostella between the cultivars.

Influência de genótipos de couve (Brassica oleracea L. var. acephala DC.) na biologia de Plutella xylostella (L., 1758) (Lepidoptera: Plutellidae) / Influence of cabbage genotypes (Brassica oleracea L. var. acephala DC.) on the biology of Plutella xylostella (L., 1758) (Lepidoptera: Plutellidae)

Objetivou-se, com este trabalho, avaliar a influência de alguns genótipos de couve (Brassica oleracea L. var. acephala DC.) no desenvolvimento de Plutella xylostella (L., 1758) (Lepidoptera: Plutellidae). Os genótipos avaliados foram: Manteiga de Ribeirão Pires I-2620, Roxa I-919, Manteiga de São José, Manteiga de Monte Alegre, Pires 2 de Campinas, Couve Comum, Couve de Arthur Nogueira 2, Couve de Arthur Nogueira 1. Lagartas recém-eclodidas foram mantida em discos foliares de 8 cm de diâmetro para cada genótipo. Foram analisados os seguintes parâmetros: duração e viabilidade das fases larval e pupal, longevidade e fecundidade de adultos, utilizando análises paramétricas e de agrupamentos para interpretação dos dados. Observou-se um prolongamento em dias no ciclo de P. xylostella, aumento no peso de pupa e maiores valores de viabilidade e fecundidade, durante a segunda geração. O genótipo Couve de Arthur Nogueira 2 foi menos favorável ao desenvolvimento de P. xylostella nas duas gerações, e Couve Comum demonstrou maior influência negativa ao inseto na segunda geração. Manteiga de Ribeirão Pires I-2620 foi o mais suscetível nas duas gerações, agrupando com este na segunda geração Pires 2 de Campinas e Manteiga de São José.

The purpose of this study was to evaluate the effect of cabbage genotypes (Brassica oleracea L. var. acephala DC.) on growth of Plutella xylostella (Lepidoptera: Plutellidae). The genotypes evaluated were: Manteiga of Ribeirão Pires I-2620, Roxa I919, Manteiga of São José, Manteiga of Monte Alegre, Pires 2 of Campinas, Couve Comum, Couve of Arthur Nogueira 2, Couve of Arthur Nogueira 1. Neonate larvae were reared in 8 cm leaf discs of each genotype. The parameters evaluated were: period and viability of the larval and pupal stages, sex ratio, longevity and fecundity of adults. Parametric and Cluster analyses were used for data analysis. Overall, it was observed a developmental delay in the P. xylostella cicle, larger pupal, higher viability and fecundity during the second generation. Couve of Arthur Nogueira 2 was less favorable to the development of P. xylostella in the two generations, and Couve Comum was not an appropriate host for the insect in the second generation. Manteiga of Ribeirão Pires I-2620 was the most susceptible in both generations belonging to the same cluster with Pires 2 of Campinas and Manteiga of São José in the second generation.

Fatores que afetam a oviposição de Bemisia tabaci (Genn. ) Biótipo B (Hemiptera: aleyrodidae) em feijoeiro / Factors acting on Bemisia tabaci (Genn. ) biotype B (Hemiptera: aleyrodidae) oviposition in common bean

Este trabalho teve por objetivo avaliar o comportamento de oviposição de Bemisia tabaci (Genn.) biótipo B, em relação à idade da planta, densidade de adultos e regiões da planta de feijoeiro, sendo utilizado o genótipo Pérola. No teste com chance de escolha foram utilizadas plantas com 20, 30 e 40 dias de idade para avaliar a preferência de oviposição do inseto. Para o teste sem chance de escolha, referentes às diferentes densidades de adultos, foram utilizadas plantas com 30 dias de idade, liberando-se 50, 100 e 150 adultos por planta. Quanto ao teste sem chance de escolha para a posição da planta (ápice, mediana e basal), adotou-se a idade de 40 dias para a liberação dos adultos. As plantas com 30 dias de idade foram preferidas para oviposição. A densidade de 100 adultos por planta propiciou oviposição adequada para discriminar genótipos quanto aos graus de resistência enquanto a região apical da planta foi a preferida para postura, portanto a mais adequada para as amostragens de ovos de B. tabaci biótipo B em plantas de feijoeiro, visando um manejo adequado da praga.

The objective of this work was to evaluate the oviposition behavior of the whitefly Bemisia tabaci (Genn.) biotype B in relation to plant age, adult density and plant region on common beans plants. The genotype Perola was used to do the test. In free-choice tests 20, 30 and 40 day-old plants were used where evaluated the oviposition Fatores que afetam... JESUS, F. G. et al. Biosci. J., Uberlândia, v. 27, n. 2, p. 190-195, Mar./Apr. 2011 194 preference of the insect. In no-choice test, 30 day-old plants were used to evaluate densities of 50, 100 and 150 adults per plants. No-choice test for plant position (apex, median, base) 40 day-old plants were adopted for liberation of adults. The 30 and 40 day-old plants were preferred for oviposition, the densities of 100 adults per plants ensured the number of eggs enough to discriminate common beans genotypes with different whitefly resistance degrees, and apical region of plant were preferred for whitefly egg laying and therefore more suitable for egg sampling in common bean plants.

Efeito de quatro tipos de mel na longevidade e reprodução de Catolaccus grandis (Hymenoptera: pteromalidae) / Effect of four types of honey on longevity and reproduction of Catolaccus grandis (Hymenoptera: Pteromalidae)

O trabalho teve como objetivo conhecer o melhor tipo de mel em relação à longevidade e fertilidade do parasitóide do bicudo-do-algodoeiro Catolaccus grandis. Adultos recém-emergidos foram transferidos para recipientes plásticos de 500mL, adaptados com tubo para fornecer água e umidade para os insetos. Um casal do parasitóide foi mantido em cada recipiente em câmara climatizada a 25±1°C, UR = 70±10 por cento e fotoperíodo de 14h. O trabalho constou de 4 tratamentos: mel de flor de laranjeira; mel de flores de plantas silvestres; mel de cana-de-açúcar (todos produzidos por Apis mellifera) e mel de flores silvestres produzido por abelha Jataí (Tetragonistica angustula), com 15 repetições cada. Adultos recém-emergidos do parasitóide receberam cinco larvas de Euscepes postfasciatus encapsuladas em parafilm. Três gotículas de mel foram colocadas sobre o parafilm. Calculou-se a longevidade de machos e fêmeas, número de ovos dia-1 fêmea-1 e número total de ovos fêmea-1 e construíram-se as tabelas de fertilidade. As melhores dietas para alimentar adultos de C. grandis foram o mel silvestre e o de laranjeira. A melhor fecundidade foi observada na dieta de mel de laranjeira (101,60 ovos fêmea-1) e os melhores resultados para aumento reprodutivo e populacional deste parasitóide foram obtidos com mel de laranja e com mel silvestre.