ABSTRACT Corn, Zea mays (L.), is one of the most expressive crops in Brazil, due to its wide-ranging uses as animal feeding, biofuel production or used for human consumption. However, there is a huge gap between the actual yield and the natural yield potential of the crop, due to insects’ attack. Leptoglossus zonatus (Dallas) (Hemiptera: Coreidae) is a key corn pest in seed producing regions, due to its attack on corn ears. Plant resistance is a valuable tool for Integrated Pest Management systems and may maintain insect populations at a level that is below an economic or damage threshold. This study aimed to evaluate the biological performance of L. zonatus in different corn genotypes, under laboratory conditions, searching for possible characterization of antibiosis/antixenosis. To achieve this goal, ten nymphs (1st instar) were transferred to polyvinylchloride (PVC) ring containing a corn ear (R6) of each genotype. Each ring corresponded to one replicate, for a total of five replicates per genotype in a completely randomized design. The parameters assessed included the duration of each instar, nymphal period, nymphal survival (%), percentage of mortality of each nymphal stage, adult longevity, and adult weight. The results demonstrate that XB 8018 Bt, 30F53, IAC Airan, XB 8030 and 30F53 YHR genotypes reduced the mean survival and caused high mortality of L. zonatus nymphs at the second instar (above 75.00%) indicating the occurrence of antibiosis/antixenosis. The higher mortality rates were observed at the second nymphal instar.

ABSTRACT Aphis gossypii Glover (Hemiptera: Aphididae), also known as the cotton aphid, is a notable pest of several crops. Its damage can be direct and indirect. The direct damage is due to its feeding, which causes leaf shriveling, deformation of shoots, and loss of plant vigor. The pest’s indirect damage is through virus transmission to cotton. In Brazil, A. gossypii is considered as a pest to several crops, but there are no references to infestations of this aphid in soybeans. The objectives of this manuscript were to report the presence of A. gossypii infesting and colonizing soybean crops in São Paulo state, Brazil, and to alert the scientific community and farmers about this possible new pest in Brazilian soybean fields.

RESUMO Bemisia tabaci (Hemiptera: Aleyrodidae) é um inseto polífago que causa danos diretos e indiretos na cultura do tomateiro. A pulverização com inseticidas sintéticos é um dos principais métodos de controle, porém, o uso abusivo dessa ferramenta pode impactar o ambiente e os seres humanos. Este estudo avaliou a bioatividade de extratos de plantas das famílias Asteraceae e Meliaceae sobre B. tabaci biótipo B em tomateiro. Um ensaio preliminar avaliou os efeitos dos extratos a 2% (p/v) sobre a infestação e oviposição dessa mosca-branca. Os efeitos ninficida e ovicida do extrato clorofórmico de Trichilia pallida - TP-Cl em seis concentrações foram avaliados. Finalmente, a TP-Cl CL50 foi estimada. Todos os extratos foram repelentes para a mosca-branca, com exceção de T. pallida (etanólico) e Melia azedarach (hexânico), considerados neutros em 24 h. Todos os extratos causaram deterrência para oviposição. Todas as concentrações de TP-Cl apresentaram atividade ninficida e as maiores promoveram as menores médias de viabilidade de ovos. A CL50 foi de 0,0955%. Os resultados evidenciaram o potencial dos extratos para serem usados como agentes alternativos de controle de B. tabaci biótipo B em tomateiro.

ABSTRACT Bemisia tabaci (Hemiptera: Aleyrodidae) is a polyphagous insect that causes direct and indirect damage on tomato. Spraying with synthetic insecticides is one of the main control tools for the whitefly; however, the abusive use of this tool can impact the environment and human beings. In this study we evaluated the bioactivity of extracts from plant species from Asteraceae and Meliaceae families on B. tabaci biotype B in tomato. A preliminary bioassay evaluated the effects of the extracts at 2% (w/v) on infestation and oviposition of this whitefly. Then, the nymphicidal and ovicidal effects of the chloroformic extract of Trichilia pallida - TP-Cl at six concentrations were performed. Finally, the TP-Cl LC50 was estimated. All extracts were repellent to the whitefly, except that ones from T. pallida (ethanolic) and Melia azedarach (hexanic), considered neutral at 24 h. All the extracts caused deterrence of oviposition. All concentrations of TP-Cl revealed nymphicidal activity and the highest ones provided the lowest egg viability averages. The estimated LC50 was 0.0955%. These results provide evidence for the potential of the extracts to be used as alternative control agents of B. tabaci biotype B in tomatoes.

ABSTRACT The silverleaf whitefly Bemisia tabaci biotype B is one of the most important sucking pests of common bean, which causes severe damages and requires frequently synthetic insecticides spraying to protect crop productivity. The use of common bean cultivars resistant to whitefly attack is an important strategy within an integrated pest management (IPM) program. The biological development of B. tabaci confined to 17 bean genotypes was evaluated in greenhouse trials to verify the occurrence of antibiosis. Whitefly adults were released on plants of these genotypes to oviposit, afterward the incubation period of eggs, nymphal period, complete development period (egg–adult), and viability of the silverleaf whitefly nymphs were recorded. As main results, genotype CHIP 300 prolonged the developmental period from egg to adult (~10 days) and BRS Estilo, Arcelina 4, IPR Garça, Tybatã, CHIP 300, IPR Eldorado, H96A102-1-1-1-52, SCS-202-Guará and CHIB 06 caused nymphal mortality, suggesting high levels of antibiosis and/or antixenosis. These genotypes may be helpful in common bean breeding programs aimed at developing commercial cultivars resistant to B. tabaci biotype B.

ABSTRACT The soybean looper Chrysodeixis includens is one of the main defoliating pests of soybean cultures in Brazil. This work aimed to evaluate the effect of offering different soybean genotypes to this insect to verify the occurrence of antixenosis. In a greenhouse, assays were carried out to determine the attractiveness of C. includens adults given free-choice tests. This experiment used a randomized block design with five replicates. A second experiment assessed oviposition preference using no-choice tests, employing a completely randomized design with five replicates. Seventeen soybean cultivars were used; several of these had previously been reported as carriers of resistance to more than one species of insect. In the laboratory, a morphological analysis was carried out by quantifying the number of trichomes on leaf surfaces and evaluating the color of the leaf blade of the germplasm. In the attractiveness assay, genotypes ‘IAC 19’, ‘IAC 18’, ‘IAC 23’, L1-1-01, PI 274453, PI 229358, PI 171451, ‘IAC 100’, ‘IAC 24’, ‘IAC 17’ and IAC 74-2832 were classified as repellents. In the oviposition preference experiment, PI 171451, PI 274453, ‘IAC 18’, L1-1-01 and ‘IAC 23’ showed the fewest eggs. The high density of trichomes presented by the genotypes PI 227687 and PI 274453 stand out as a possible C. includens resistance factor. The genotype L1-1-01 presented intermediate luminosity (L*) and more intense green (a*) and yellow (b*) colors compared to other genotypes. There was no correlation between oviposition and trichome density or leaf coloration.

ABSTRACT Some species of pentatomids stink bugs have global economic importance, damaging various plant species during the vegetative and reproductive phases. Dichelops melacanthus (Dallas) (Hemiptera: Pentatomidae), known as the green-belly stink bug, is part of the soybean stink bug complex in Brazil and has increasing importance in crops,with potential to reduce crop yield. This polyphagous stink bug has been registered in 29 plant species belonging to 10 plant families which include cultivated and non-cultivated plants. Plant resistance is a valuable tool in integrated pest management and may reduce insect populations below economic injury level. This study characterized the resistance of 17 soybean genotypes to the green-belly stink bug. All of the materials affected the biological performance of the green-belly stink bug, but PI 227687; ‘IAC 100’; PI 171451; IAC 78-2318; D 75-10169; IAC 74-2832; ‘IAC 23’ and ‘IAC 24’ caused mortality above 80% in the second instar. ‘IAC 17’; ‘IAC 18’; PI 171451; PI 274454; ‘Conquista’ and ‘IAC 19’ decreased the longevity of adults of D. melacanthus, showing the same mechanism of resistance. PI 227687 did not allow any insects to complete the immature stage. These results are unprecedented for the species D. melacanthus and can assist breeding programs that focus on resistance to members of the stink bug complex in soybean.

RESUMO: O objetivo do trabalho foi avaliar o efeito de pós de oito espécies botânicas, misturados aos grãos de feijão, Phaseolus vulgaris (Fabaceae), ou em sachês, sobre os aspectos comportamentais e de desenvolvimento biológico de Zabrotes subfasciatus (Coleoptera: Chrysomelidae: Bruchinae) em laboratório. Três ensaios foram realizados. Primeiro, a repelência de adultos de Z. subfasciatus pelas espécies vegetais foi avaliada com 20 casais em teste com chance de escolha. Segundo, a mortalidade de adultos foi avaliada, diariamente, até o sétimo dia após a infestação. Terceiro, sete casais foram mantidos por sete dias em recipientes contendo 0,3 g de pó de cada espécie vegetal e 10 g de grãos de feijão (3% p.p-1) para avaliação dos parâmetros oviposição, emergência de adultos (%) e período de desenvolvimento ovo-adulto (dias) de Z. subfasciatus. Os ensaios seguiram arranjo fatorial 2 x 9 (fator 1 = formas de aplicação pó e sachê; fator 2 = oito espécies vegetais e testemunha) em delineamento inteiramente casualizado com oito repetições. A forma de pó foi mais eficiente no controle de Z. subfasciatus. As espécies Azadirachta indica (na forma de pó), Ruta graveolens (na forma de pó) e Piper aduncum (na forma de sachê) reduziram a infestação por adultos do inseto. A. indica, Piper tuberculatum, Trichilia catigua, Pfaffia glomerata, R. graveolens e Mentha pulegium, independente da forma de aplicação utilizada, inibiram a oviposição do inseto. R. graveolens (na forma de pó) controlou 100% de adultos. Pós das espécies R. graveolens e M. pulegium reduziram a viabilidade de ovos e emergência do inseto, apresentando alto potencial no controle alternativo de Z. subfasciatus em feijão armazenado.

ABSTRACT: This study aimed to evaluate the insecticidal activity of eight botanical species in the behavior and biological development of Zabrotes subfasciatus (Coleoptera: Chrysomelidae: Bruchinae) under laboratory conditions. The botanical species were applied on bean grains (Phaseolus vulgaris Linnaeus) directly as powder or indirectly within TNT bags. Three laboratory assays were performed. First, a repellent activity test was performed by exposing twenty couples of Z. subfasciatus adults in a choice-test arena. Second, a mortality test was performed for seven days after infestation. Finally, the oviposition and emergency rates of adults (%) and the development from egg to adult (in days) were evaluated in seven couples (males and females) for seven days inside of a vial containing 0.3g of the powder from each botanical species and 10 g of bean grains (3% w.w-1). The study was conducted in a completely randomized design, and the treatments were arranged as a factorial design (2 x 9) with two factors (factor 1= powder and TNT bag application forms and factor 2= eight botanical species and control) with eight replications. The powder application form was more efficient in controlling Z. subfasciatus. Azadirachta indica (powder application), Ruta graveolens (powder application), and Piper aduncum (TNT bag) reduced the infestation of adults. The species A. inidica, Piper tuberculatum, Trichilia catigua, Pfaffia glomerata, R. graveolens, and Mentha pulegium inhibited the oviposition of the insects regardless of the formulation applied. R. graveolens (powder application) caused 100% of mortality. The powder application of R. graveolens and M. pulegium reduced egg viability and insect emergence; therefore, they are very promising alternatives to control Z. subfasciatus in stored grains.

O objetivo deste trabalho foi avaliar genótipos de feijoeiro quanto à resistência a lagarta-falsa-medideira (Chrysodeixis includens). Inicialmente, foram realizados testes com chance de escolha com 59 genótipos, divididos em três grupos, de acordo com a intensidade de coloração das folhas (verde-escura, verde-clara e verde-médio), para avaliar a preferência quanto à oviposição. Em seguida, selecionaram-se 12 genótipos com grande potencial de resistência, assim como dois padrões comerciais suscetíveis. Com estes genótipos, realizaram-se novos ensaios de oviposição, em casa de vegetação, além de testes de atratividade e consumo, em condições de laboratório (26±2ºC, 65±10% UR e fotófase de 14 h luz: 10 h escuro). No teste sem chance de escolha, com adultos, em casa de vegetação, os genótipos 'IAC Jabola', Arcelina 1, 'IAC Boreal', 'Flor de Mayo' e 'IAC Formoso' foram os menos ovipositados, tendo apresentado resistência do tipo antixenose à oviposição. No teste com chance de escolha, com larvas, Arcelina 4, 'BRS Horizonte', 'Pérola', H96A102-1-1-1-52, 'IAC Boreal', 'IAC Harmonia' e 'IAC Formoso' foram os genótipos menos consumidos, o que indica antixenose à alimentação. No teste sem chance de escolha, todos os genótipos (exceto 'IAPAR 57') expressaram níveis moderados de antixenose à alimentação de larvas de C. includens.

The objective of this work was to evaluate bean genotypes for resistance to soybean looper (Chrysodeixis includens). Initially, free-choice tests were carried out with 59 genotypes, divided into three groups according to leaf color intensity (dark green, light green, and medium green), in order to evaluate oviposition preference. Subsequently, 12 genotypes with high potential for resistance were selected, as well as two susceptible commercial standards. With these genotypes, new tests were performed for oviposition in a greenhouse, besides tests for attractiveness and consumption under laboratory conditions (26±2ºC, 65±10% RH, and 14 h light: 10 h dark photophase). In the no-choice test with adults, in the greenhouse, the 'IAC Jabola', Arcelina 1, 'IAC Boreal', 'Flor de Mayo', and 'IAC Formoso' genotypes were the least oviposited, showing antixenosis-type resistance for oviposition. In the free-choice test with larvae, Arcelina 4, 'BRS Horizonte', 'Pérola', H96A102-1-1-1-52, 'IAC Boreal', 'IAC Harmonia', and 'IAC Formoso' were the less consumed genotypes, which indicates antixenosis to feeding. In the no-choice test, all genotypes (except for 'IAPAR 57') expressed moderate levels of antixenosis to feeding against C. includens larvae.

O objetivo deste trabalho foi avaliar a bioatividade de extratos etanólicos de folhas de quatro espécies do gênero Piper sobre a traça-do-tomateiro Tuta absoluta (Lepidoptera: Gelechiidae), em condições de laboratório. As espécies avaliadas foram: P. amalago var. medium, P. glabratum, P. mikanianum e P. mollicomum. Na triagem inicial (concentração do extrato de 2.000 mg L-1), todos os extratos testados causaram significativa mortalidade larval, principalmente o extrato de P. amalago var. medium; entretanto, nenhum extrato ocasionou redução do peso das lagartas sobreviventes. O extrato de P. amalago var. medium na concentração de 1.011 mg L-1 promoveu alongamento significativo da fase larval e pupal. O extrato etanólico de folhas de P. amalago var. medium é promissor no controle de lagartas de T. absoluta em tomateiro, pois exibe toxicidade aguda a lagartas na concentração de 2.000 mg L-1 e afeta o desenvolvimento do inseto, ao reduzir a sua sobrevivência e alongar as fases larval e pupal.

The objective of this work was to evaluate the bioactivity of ethanolic leaf extracts from four species of the genus Piper against the tomato leafminer Tuta absoluta (Lepidoptera: Gelechiidae) under laboratory conditions. The evaluated species were: P. amalago var. medium, P. glabratum, P. mikanianum, and P. mollicomum. In the initial screening assay (extract concentration of 2,000 mg L-1), all tested extracts caused significant larval mortality, particularly the extract of P. amalago var. medium; however, no extracts reduced the weight of the surviving larvae. The extract from P. amalago var. medium at the concentration of 1,011 mg L-1 caused a significant lengthening of the larval and pupal stages. The ethanolic leaf extract of P. amalago var. medium is promising for the control of T. absoluta larvae in tomato, since it exhibits acute toxicity toward these caterpillars at the concentration of 2,000 mg L-1 and affects the insect's development by reducing its survival and lengthening the larval and pupal stages.

This study aimed to evaluate the effects of nitrogen availability in fertigation and rainfed management, as well as their interactions with the incidence of and damage caused by D. saccharalis and red rot in sugarcane. The experiment consisted of four treatments (0 and 150 kg ha–1 of N-fertilizer with irrigation; 0 and 150 kg ha–1 of N-fertilizer in rainfed management) in a randomized complete block design with four replications. The evaluated parameters were the number of holes and internodes with red rot per meter of cultivation, stalk yield and sugar content. In the laboratory (T = 25 ± 2 °C; R.H. = 70 ± 10%: 12:12-L:D), we evaluated the attractiveness and consumption of fragments of stalks from the different treatments for fourth instar larvae through choice and no-choice tests in a randomized complete block design with ten replications. Nitrogen fertilization via irrigation has favorable effects on borer-rot complex and leads to higher gains in stalk and sugar yields when compared to rainfed management. The increments of stalk and sugar yields due to nitrogen fertilization compensates for the increase in borer-rot complex infestation. In laboratory tests, D. saccharalis larvae were similarly attracted to all treatments regardless of the doses of N-fertilizer or the water regimes evaluated. However, fragments of sugarcane stalks produced with nitrogen fertilization were consumed more by D. saccharalis in both water regimes.

O Brasil se destaca como o maior produtor mundial de cana-de-açúcar e sua produtividade está intimamente relacionada à disponibilidade de água e nitrogênio durante seu desenvolvimento e também à incidência de insetos-praga. Dentre as espécies mais nocivas à cana-de-açúcar no Brasil, destaca-se Mahanarva fimbriolata, a qual tem comprometido seriamente sua produtividade. Nesse contexto, o presente trabalho teve como objetivo avaliar o efeito da fertirrigação nitrogenada sobre a incidência e os danos ocasionados por M. fimbriolata em cana-de-açúcar. O experimento foi composto por cinco tratamentos e quatro repetições em delineamento de blocos casualizados (DBC). Os tratamentos foram constituídos por quatro doses de N-fertilizante e controle (0, 50, 100, 150 e 200 kg.ha-1) em sistema de irrigação por gotejamento. Os parâmetros avaliados foram: número de ninfas nas raízes, produtividade de colmos (TCH), produtividade de açúcar (TPH), açúcar total recuperável (ATR), pol de cana corrigido (PCC) e margem de contribuição agrícola. Foi observado que a produtividade de colmos e de açúcar aumentou com a adubação nitrogenada por meio da irrigação. O uso de 200 kg.ha-1 de N-fertilizante elevou a incidência de M. fimbriolata até os níveis de controle e dano econômico. O maior rendimento financeiro foi obtido com a dose de 150 kg.ha-1 de N-fertilizante.

Brazil stands out as the world's largest producer of sugarcane and its productivity is closely related to the availability of water and nitrogen during its development and also to the incidence of pest insects. Among the species most harmful to the sugarcane in Brazil, Mahanarva fimbriolata stands out, which has seriously endangered the yields. In this context, the present study aimed to evaluate the effect of the nitrogen fertirrigation on the incidence and damage caused by M. fimbriolata in sugarcane. The experiment was composed of five treatments and four replications in a randomized block design (RBD). The treatments were composed of four doses of N-fertilizer and control (0, 50, 100, 150, 200 kg.ha-1) in drip irrigation system. The parameters evaluated were: number of nymphs in the roots, stalk productivity, sugar content, percentage of sugar, total recoverable sugar and the agricultural contribution margin. It was observed that the fertirrigation increases the productivity of stalks and sugar with the increase of nitrogen fertilization by irrigation. The use of 200 kg.ha-1 of N-fertilizer increased the incidence of M. fimbriolata up to the control and economic damage levels. The biggest financial yield was obtained with the dose of 150 kg.ha-1 of N-fertilizer.

A mosca branca Bemisia tabaci (Hemiptera: Aleyrodidae) é considerada uma das pragas agrícolas mais ameaçadoras em todo o mundo, pelo seu efeito direto na sucção de seiva das plantas e principalmente pelo seu efeito indireto de transmitir vírus, em especial os begomovírus. No Brasil, a espécie de begomovírus predominante em solanáceas é o Tomato severe rugose vírus - ToSRV. Uma possibilidade de manejo da doença é a utilização de cultivares resistentes ou tolerantes tanto ao vírus, como ao inseto vetor. Foram avaliados neste trabalho a dispersão primária e secundária do ToSRV por Bemisia tabaci, espécie MEAM1, também conhecida como biótipo B, em cultivares tolerantes ao ToSV Capsicum baccatum (IAC-1357) C. annuum (IAC-1566) e C. frutescens (IAC-1544). O genótipo (IAC-1544) apresentou menor número de plantas infectadas pelo ToSRV no ensaio de dispersão primária e nenhuma eficiência na transmissão do isolado na dispersão secundária. Estes resultados colaboram para o melhoramento de pimentão e pimentas visando a resistência ao ToSRV e seu inseto vetor.

The whitefly Bemisia tabaci (Hemiptera : Aleyrodidae) is considered one of the most threatening agricultural pests in the world due to its direct effect on the suction of sap from plants and especially due to its indirect effect in transmitting viruses, particularly the begomovirus. In Brazil, the predominant species of begomovirus within Solanaceae is Tomato severe rugose virus - ToSRV. A possibility of management of this disease is the use of cultivars that are resistant or tolerant to both the virus and the insect vector. This study evaluated the primary and secondary dispersal of ToSRV by B. tabaci, MEAM1 species, also known as biotype B, usin ToSRV-tolerant species Capsicum baccatum (IAC-1357), C. annuum (IAC -1566) and C. frutescens (IAC-1544). The genotype IAC -1544 showed a smaller number of plants infected by ToSRV during the primary dispersal assay and no efficiency in the isolate transmission in the secondary dispersal. These results contribute to capsicum and pepper breeding forresistance to ToSRV and its insect vector.

Desde 2009, populações crescentes de Chrysodeixis includens (Walker) (Lepidoptera: Noctuidae) vêm sendo observadas em lavouras de feijoeiro comum (Phaseolus vulgaris L.) e mamoneira (Ricinus communis L.), na Fazenda Experimental Lageado, pertencente à FCA/UNESP, Campus de Botucatu, Estado de São Paulo, Brasil. Desfolhas ao redor de 80% e 50% foram constatadas em feijoeiro Pérola e em mamoneira IAC-2028, respectivamente. Amostras de indivíduos (lagartas e pupas) foram coletadas a campo e mantidas em laboratório até a emergência dos adultos para confirmação da espécie. Essas observações em feijoeiro são inéditas para o estado de São Paulo e, no caso da mamoneira, inéditas no Brasil, sugerindo que o inseto vem se adaptando e atacando outras culturas de interesse agrícola, exigindo maior atenção por parte dos produtores de feijão e mamona.

Since 2009, increasing populations of Chrysodeixis includens (Walker) (Lepidoptera: Noctuidae) have been observed in cultivated common bean (Phaseolus vulgaris L.) and castor bean (Ricinus communis L.) at the Lageado Experimental Farm, belonging to the FCA/UNESP, Botucatu, São Paulo State, Brazil. Defoliations around 80% and 50% were observed in the common bean cv. Pérola and castor bean cv. IAC-2028, respectively. Samples of individuals (caterpillars and pupae) were collected in the field, and kept in laboratory until adult emergence aiming to confirm the species. These are new observations for common bean in São Paulo State and, in the case of castor bean, unpublished in Brazil. It suggests that C. includens has adapted to attack other agricultural crops, demanding attention of common bean and castor bean producers.

O objetivo deste trabalho foi caracterizar a resistência de 50 genótipos de feijão-caupi (Vigna unguiculata) a Callosobruchus maculatus. Utilizou-se o delineamento inteiramente casualizado com cinco repetições por tratamento (genótipo). Testes de confinamento foram realizados com os 50 genótipos de feijão-caupi, para avaliar a preferência para oviposição e o desenvolvimento do caruncho. Os genótipos IT85 F-2687, MN05-841 B-49, MNC99-508-1, MNC99-510-8, TVu 1593, Canapuzinho-1-2 e Sanzi Sambili apresentam resistência do tipo não preferência (oviposição e alimentação). IT81 D-1045 Ereto e IT81 D-1045 Enramador apresentam antibiose contra C. maculatus e descendem de genitores resistentes, o que lhes confere potencial para serem utilizados em futuros cruzamentos, para obtenção de variedades de feijão-caupi com maior nível de resistência.

The objective of this work was to characterize the resistance of 50 cowpea (Vigna unguiculata) genotypes to Callosobruchus maculatus. A completely randomized design with five replicates per treatment (genotype) was used. No-choice tests were performed using the 50 cowpea genotypes to evaluate the preference for oviposition and the development of the weevil. The genotypes IT85 F-2687, MN05-841 B-49, MNC99-508-1, MNC99-510-8, TVu 1593, Canapuzinho-1-2, and Sanzi Sambili show non-preference-type resistance (oviposition and feeding). IT81 D-1045 Ereto and IT81 D-1045 Enramador exhibit antibiosis against C. maculatus and descend from resistant genitors, which grants them potential to be used in future crossings to obtain cowpea varieties with higher levels of resistance.

O objetivo deste trabalho foi avaliar o efeito da fertirrigação nitrogenada sobre os danos causados pelo complexo broca-podridão à produtividade e à qualidade da cana-de-açúcar. O experimento foi realizado em campo, em delineamento de blocos ao acaso, com quatro repetições e cinco doses de N (0, 50, 100, 150 e 200 kg ha-1), aplicadas por irrigação por gotejamento. Quantificaram-se as seguintes variáveis: número de orifícios causados por Diatraea saccharalis (Lepidoptera: Crambidae); número de internódios infectados com a podridão-vermelha; percentagem de incidência de podridão-vermelha; produtividade de colmos; e teor de açúcar. Em laboratório, foram avaliados a atratividade e o consumo de fragmentos de colmos por lagartas de quarto instar, em testes com ou sem chance de escolha. A irrigação nitrogenada aumentou a incidência de D. saccharalis e de podridão-vermelha. O número de orifícios causados pelas lagartas correlacionou-se à ocorrência de podridão-vermelha. A percentagem de açúcar diminuiu com o aumento do número de internódios danificados pela podridão-vermelha. As doses de N não afetaram a atratividade dos fragmentos de colmos de cana-de-açúcar; no entanto, maiores doses de N fertilizante aumentaram o consumo destes fragmentos por lagartas de D. saccharalis. Apesar dos danos à qualidade, a adubação nitrogenada aumentou expressivamente a produtividade de colmos e de açúcar.

The objective of this work was to evaluate the effect of nitrogen-fertigation on the damage caused by the borer-rot complex to the productivity and quality of fertigated sugarcane. The experiment was carried out in field, using a randomized complete block design, with four replicates and five N doses (0, 50 100, 150, and 200 kg ha-1) applied through drip irrigation. The following variables were determined: number of holes caused by Diatraea saccharalis (Lepidoptera: Crambidae); number of internodes infected with red rot; incidence percentage of red rot; stalk productivity; and sugar content. In laboratory, the attractiveness and the consumption of culm fragments by fourth instar caterpillars, in trials with or without choice, were evaluated. Nitrogen fertigation increased the incidence of D. saccharalis and red rot. The number of holes produced by the larvae was correlated with the occurrence of red rot. Sugar percentage reduced with the increase in the number of red rot affected internodes. Nitrogen doses did not affect the attractiveness of sugarcane culm fragments; however, higher N doses increased the consumption of these fragments by D. saccharalis caterpillars. Despite the damages to quality, nitrogen fertilization expressively enhanced the productivity of stalks and sugar.