ABSTRACT: Plectris alienaChapin, 1934, a white grub that promotes serious damage to a variety of crops in North America and Australia, has been reported for the first time in Brazil. Larvae and adults of P. aliena were recorded in sugarcane crops in the state of Mato Grosso do Sul, sampled by trenches in the soil with light traps, respectively, during 2012 and 2013. Root consumption was also determined for the first, second and third instar larvae. The species is univoltine; adults were found mainly in Aug and the peak of third instar larval density was in Apr in all fields sampled. Pupae and adults of P. aliena were observed in the soil profile at depths of up to 60 and 80 cm, respectively. Larvae of P. aliena of the second and third instar consumed the primary and secondary roots of sugarcane, causing serious damage. Third instar larvae consumed 916 mg of root fresh matter, representing 72 % of the sugarcane root system. These results assist in furthering the understanding of its larval dynamics in the soil and provide support for Integrated Pest Management.

ABSTRACT The fall armyworm (Spodoptera frugiperda) is a major maize (Zea mays L.) pest in Brazil, whose larvae cause losses from plant emergence to harvesting stage. This pest has been controlled almost exclusively with chemical insecticides and Bt plants (transgenics); however, resistance evolution has been detected to these two control tactics. Therefore, alternative control tactics are needed for management and control of the fall armyworm. Thus, this study aimed to evaluate the resistance of maize landraces from Brazil to larvae of this herbivore in the winter and summer seasons, studying also the occurrence of the predator Doru luteipes (Dermaptera: Forficulidae). The variety Pérola had the highest resistance levels to fall armyworm in the summer season, with lower values of leaf injury, number of infested plants, and number of larvae. Conversely, this variety did not express resistance to the pest in winter. Doru luteipes was found abundantly in the summer season, showing no differences between varieties. This is the first study to evaluate the resistance of maize landraces from Brazil to fall armyworm in the winter and summer seasons. The next step is the molecular characterization of the variety Pérola, as well as evaluating its effects on the most common natural enemies of the pest in Brazil, such as the predator D. luteipes and the egg parasitoid Trichogramma pretiosum (Hymenoptera: Trichogrammatidae). These results may assist future maize breeding programs aimed at developing cultivars and hybrids resistant to the pest, and hence reducing agriculture’s dependence on chemical insecticides and transgenic plants.

The southern armyworm Spodoptera eridania is a polyphagous species that can feed on cowpea plants. Although there is some knowledge about the resistance of cowpea cultivars, little is known on the effects of neem oil to control pest insects of cowpea in Brazil. This study aimed to evaluate the effects of cowpea cultivars combined with neem oil on attractiveness, feeding, and development of Spodoptera eridania (Cramer). The experiment was carried out under environmentally controlled conditions, and set up in a 6 x 3 factorial arrangement using six cowpea cultivars and two doses of neem oil plus the control (deionized water). Free-choice and no-choice feeding preference assays were performed to assess treatment attractiveness to the larvae and leaf consumption. Duration and survival of larvae, pre-pupae, and pupae, weights of larvae and pupae, longevity of adults, sex ratio, duration of larva-to-adult period, and larval mortality after 3, 6, 12, and 24 days were recorded. Cultivars BRS Urubuquara and BR17 Gurgueia were the least consumed in the free-choice test. Neem oil at 0.35 and 0.7% reduced leaf consumption. Cultivars BRS Novaera and BR17 Gurgueia showed to be the least suitable for S. eridania development. Neem oil at both doses affected S. eridania development. Cultivars BR7 Gurgueia and BRS Novaera were moderately resistant; BR3 Tracuateua, susceptible; and Sempre Verde, Milênio, and BRS Urubuquara were highly susceptible to S. eridania.

Spodoptera eridania es una especie polífaga, cuya oruga puede alimentarse de plantas de caupí. Aunque hay algunos conocimientos sobre la resistencia de cultivares de caupí, se conoce poco sobre los efectos de aceite de nim para controlar insectos plaga de caupí, en Brasil. Esta investigación tuvo como objetivo evaluar los efectos de cultivares de caupí asociados con aceite de nim sobre la atracción, alimentación, y desarrollo de Spodoptera eridania (Cramer). El experimento se llevó a cabo bajo condiciones ambientales controladas, en un diseño factorial 6x3, evaluando seis cultivares de caupí y dos dosis de aceite de nim, además del tratamiento testigo (agua desionizada). Se realizaron pruebas de no preferencia para alimentación con y sin opción de escoger para evaluar la atracción de los tratamientos a las larvas y el consumo de las hojas. Se registró la duración y supervivencia de larvas, prepupas y pupas, pesos de larvas y pupas, longevidad de los adultos, proporción sexual, duración del período de larva a adulto, y mortalidad larval después de 3, 6, 12, y 24 días. Los cultivares BRS Urubuquara y BR17 Gurgueia fueron los menos consumidos en la prueba de libre elección. El consumo de hojas fue reducido cuando utilizó aceite de nim a 0,35 y 0,7%. Los cultivares BRS Novaera y BR17 Gurgueia mostraron ser los menos adecuados para el desarrollo de S. eridania. Aceite de nim en ambas dosis afectó el desarrollo de S. eridania. Los cultivares BR7 Gurgueia y BRS Novaera fueron moderadamente resistentes; BR3 Tracuateua, susceptible; y Sempre Verde, Milênio, y BRS Urubuquara fueron altamente susceptibles a S. eridania.

Diante da crescente importância de Cerotoma arcuata nos últimos anos, devido aos prejuízos econômicos causados à cultura da soja, ausência de inseticidas registrados no Brasil e escassez de informações a respeito de cultivares resistentes, este trabalho objetivou avaliar a preferência alimentar de adultos e o desenvolvimento pós-embrionário de C. arcuata, em cultivares e linhagem de soja, visando a encontrar possíveis fontes de resistência. Utilizaram-se as cultivares comerciais BRSMG 750 SRR, M-SOY 7908 RR e P 98Y30 RR e a linhagem PI 274454 (padrão de resistência a partir de resultados com Diabrotica speciosa). No teste de preferência alimentar com e sem chance de escolha, foi avaliada a atratividade em diferentes tempos, após a liberação dos adultos, e a área foliar consumida, ao final do experimento. No teste de antibiose, foram avaliados o período e a viabilidade de desenvolvimento pós-embrionário, massa de adultos, razão sexual e longevidade de adultos sem alimento. Em geral, não houve diferenças na atratividade para os adultos e área foliar consumida entre as cultivares e linhagem de soja. Apenas a longevidade dos adultos foi maior na linhagem PI 274454 e menor na cultivar BRSMG 750 SRR. As cultivares comerciais de soja não apresentaram resistência dos tipos não preferência para alimentação ou antibiose a C. arcuata, e a linhagem PI 274454 não deve ser utilizada como padrão de resistência, em testes de resistência a esta espécie.

Considering the increasing importance of Cerotoma arcuata in the last years, due to the economical losses caused on soybean crop, absence of insecticides registered in Brazil and lack of information about resistant cultivars, this study aimed to assess the feeding preference of adults and postembryonic development of C. arcuata on soybean cultivars and breeding line, in an attempt to find potential sources of resistance. The BRSMG 750 SRR, M-SOY 7908 RR and P 98Y30 RR commercial cultivars and the PI 274454 breeding line (used as the resistance standard from results obtained with Diabrotica speciosa) were used. In both the free-choice and no-choice feeding preference test, the attractiveness in different times, after releasing the adults, and the leaf area consumed at the end of the experiment were evaluated. In the antibiosis assay, the period and viability of the postembryonic development, weight of adults, sex ratio and longevity of adults without feeding were assessed. Overall, there were no differences in the attractiveness of the adults and leaf area consumed between the soybean cultivars and breeding line. Only the longevity of adults was longer on the PI 274454 breeding line and shorter on the BRSMG 750 SRR cultivar. The soybean commercial cultivars did not present resistance of the non-preference for feeding or antibiosis kinds to C. arcuata, and the PI 274454 breeding line must not be used as a resistance standard in resistance assays against this species.

O feijão-vagem (Phaseolus vulgaris L.) pode sofrer ataque de carunchos, como os da espécie Zabrotes subfasciatus (Bohemann, 1833) (Coleoptera: Chrysomelidae), afetando, diretamente, a qualidade das vagens e sementes e deixando-as inviáveis para o consumo e comercialização. A fim de buscar uma alternativa para o controle deste inseto, foram determinados os tipos e graus de resistência, envolvidos em genótipos de feijão-vagem, ao ataque de Z. subfasciatus, em testes com e sem chance de escolha. Os genótipos utilizados foram UEGD7, UEG05, UEG06, UEG11, UEG13, UEG15, UEG18, UEG19 e UEG26, com quatro repetições. No teste com chance de escolha, os parâmetros avaliados foram o número de ovos viáveis, inviáveis e total e a atratividade dos adultos pelos genótipos. No teste sem chance de escolha, foram avaliados o número de ovos viáveis, inviáveis e total, massa seca consumida e massa seca consumida por inseto, massa e longevidade dos adultos, período de ovo a adulto, razão sexual e número e percentagem de insetos emergidos. Concluiu-se que o genótipo UEG05 foi o menos preferido por Z. subfasciatus, para oviposição, em teste com chance de escolha. O UEG13 foi altamente resistente e UEG05, UEG15 e UEG19 foram moderadamente resistentes. O UEG18 foi susceptível e os demais genótipos foram altamente susceptíveis a Z. subfasciatus.

The string bean (Phaseolus vulgaris L.) can be attacked by worms of species such as the Zabrotes subfasciatus (Bohemann, 1833) (Coleoptera: Chrysomelidae), which directly affects the pods and seeds quality, making them unsuitable for consumption and commercialization. In order to find out an alternative way of controlling this insect, string bean genotypes and resistance levels to the Z. subfasciatus attack were evaluated, by using free and no-choice tests. The genotypes used were the UEGD7, UEG05, UEG06, UEG11, UEG13, UEG15, UEG18, UEG19 and UEG26, with four replications. In the free-choice test, the number of total, viable and unviable eggs and the attractiveness of adults by genotypes were evaluated. In the no-choice test, the number of total, viable and unviable eggs, dry weight consumption and dry weight consumption per insect, adult insect weight and longevity, period from egg to adult, sex ratio and number and percentage of insect emergence were evaluated. It was observed that the UEG05 genotype was the less preferred for oviposition by Z. subfasciatus, in the free-choice test. The UEG13 genotype showed to be highly resistant and the UEG05, UEG15 and UEG19 were moderately resistant. The UEG18 genotype was considered susceptible and the other ones highly susceptible to Z. subfasciatus.