186 research outputs found

    Butterflies and moths (Insecta: Lepidoptera) associated with erva-mate, the South American Holly (Ilex paraguariensis St. Hil.), in Rio Grande do Sul, Brazil

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    The result of an inventory on the lepidopteran fauna associated with the South American Holly (erva-mate) is described. This inventory was based on a bibliographic review, the examination of specimens deposited in scientific collections from the state of Rio Grande do Sul, the systematic collection within commercial erva-mate farms located in Anta Gorda, RS, and on the occasional collections from native trees within the Região dos Vinhedos campus of the Universidade de Caxias do Sul. Every fifteen days between 20 August 2005 and 19 August 2006, 150 trees were visually inspected and all Lepidoptera were collected. A list of 75 lepidopteran taxa belonging to 16 families is presented, including 27 new occurrences for the erva-mate crop, of which 14 species represent new records for the state.

    Survival and Development of Striacosta albicosta (Smith) (Lepidoptera: Noctuidae) Immature Stages on Dry Beans, non-Bt, Cry1F, and Vip3A Maize

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    Striacosta albicosta is a crop pest that causes economic damage in the United States and Canada. Only maize and dry beans are shown to be suitable hosts, since larval development is incomplete on other hosts. The objective of this study was to describe the developmental parameters of immature stages of S. albicosta feeding on dry beans, non-Bt, Cry1F, and Vip3A maize. For Vip3A, mortality was 100% after 24 h. Larvae feeding on non-Bt maize had the highest larval survival (70.6%) compared to the other hosts. Maize expressing Cry1F had higher survival (31.3%) than dry beans (26.0%). Larvae feeding on dry beans had a significantly faster total development time (74.8 days), compared to 92.5 days for non-Bt and 96.2 days for Cry1F. All larvae developed through seven instars. Pupae from larvae that had fed on non-Bt maize were significantly heavier than pupae from other hosts. An understanding of S. albicosta immature development on various host plants is needed to improve recommendations for effective scouting, treatment timing, and economic thresholds. Differential development can result in an extended adult emergence period, and possibly result in assortative mating between Bt susceptible and resistant populations, which violates the assumption of random mating necessary for current resistance management strategies for Bt maize. Therefore, understanding the impact of host plant and transgenic traits on aspects of pest biology will aid in developing effective integrated pest management and insect resistance management strategies for this pest

    Life-History Parameters of Striacosta albicosta (Lepidoptera: Noctuidae) Under Laboratory Conditions

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    Striacosta albicosta (Smith) is a key pest of maize and dry beans in North America. It has expanded its distribution from the western Great Plains of the United States to the Great Lakes region in the United States and Canada. There has been limited research on the baseline biological aspects of this insect under controlled conditions. The objective of this study was to detail the biological parameters of S. albicosta feeding on an artificial diet under laboratory conditions. Overall survival from neonate to adult at 26.6 ± 1°C was 36.72% and the total developmental time was approximately 110 d. Survival of the egg, larval, prepupal, and pupal stages were 75.71, 98.50, 51.78, and 95.10%, respectively. Average duration of the egg, larval, prepupal, and pupal stages was 4.64, 28.20, 41.50, and 25.91 d, respectively. During the larval stage, 92.50% of larvae developed through seven instars and the remaining through six instars. Larvae that developed through six and seven instars exhibited a mean growth ratio of 1.60 and 1.47, respectively; however, there was no difference in pupal weight. Eggs laid by field-mated moths showed a fertility of 75.71%, compared with 4.18% from laboratory-reared moths. These data suggest that S. albicosta develop primarily through seven instars and the most vulnerable developmental stage is the prepupa. Laboratory conditions strongly affected fertility success. Information presented here greatly expands our understanding of S. albicosta biology, which can be used to improve the efficiency of laboratory bioassays and management techniques for this critical crop pest

    Battle in the New World: \u3ci\u3eHelicoverpa armigera\u3c/i\u3e versus \u3ci\u3eHelicoverpa zea\u3c/i\u3e (Lepidoptera: Noctuidae)

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    The corn earworm Helicoverpa zea (Boddie) and the old world bollworm Helicoverpa armigera (HuÈbner) (Lepidoptera: Noctuidae) are allopatric species and occur in important agricultural crops. In maize, both species tend to infest the ear. The introduction of H. armigera in Brazil has created a new scenario, where these Helicoverpa species might cohabit and interact with one another, affecting the prevalence of each species in the agroecosystem, integrated pest management, and insect resistance management. In this study, larval occurrence and proportion of these species in maize was assessed in three regions of Brazil during three crop seasons. Interaction between the species was evaluated in interspecific and intraspecific scenarios under laboratory and field conditions. Helicoverpa zea was predominant in Rio Grande do Sul and the Planaltina, DF (central Brazil). In western Bahia, H. zea was predominant in the first collection, but approximately equal in number to H armigera in the second crop season. Both species exhibit high cannibalism/predation rates, and larval size was the primary factor for larval survival in the interaction studies. Larva of H. zea had higher survival when interacting with H. armigera, indicating that H. zea has an advantage in intraguild interactions with H. armigera in maize. Overall, the results from this study indicate that maize might play a role as a source of infestation or a sink of insecticide or Bt protein unselected H. armigera populations, depending on the H. zea:H. armigera intraguild competition and adult movement in the landscape

    Primeiro registro de Isia alcumena, Spodoptera cosmioides e Spodoptera eridania (Lepidoptera: Noctuoidea) em maracujazeiro (Passiflora edulis Sims) no Brasil

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    O Brasil é considerado o centro de origem e de diversidade das passifloras, que apresentam importância, tanto para o consumo in natura, industrialização, uso medicinal e também como plantas ornamentais. As diferentes espécies de Passiflora hospedam uma grande diversidade de artrópodes que, ocasionando injúrias, podem causar danos econômicos e morte da planta. Dentre os artrópodes, as lagartas-desfolhadoras são consideradas as pragas mais frequentes e severas nas principais regiões produtoras de maracujá. Assim, o objetivo foi informar o primeiro registro da ocorrência das espécies Isia alcumena, Spodoptera cosmioides e S. eridania atacando maracujazeiros no Distrito Federal, Brasil. As lagartas de S. cosmioides e S. eridania foram coletadas enquanto consumiam folhas de híbridos intraespecíficos de Passiflora edulis cultivado no banco ativo de germoplasma “Flor da Paixão” da Embrapa Cerrados. Já as lagartas de I. alcumena foram coletadas em folhas da cultivar BRS Rubi do Cerrado, na Unidade de Apoio da Fruticultura da Embrapa Cerrados. Após a coleta, as lagartas foram individualizadas em sistema de criação com folhas das plantas hospedeiras. O desenvolvimento das lagartas foi acompanhado até à emergência dos adultos, que foram identificados e fixados em alfinetes entomológicos para preservação permanente, a seco.Brazil is considered the center of origin and diversity of passifloras. These species have a great importance to in natura fruits consumption, industrialization, medicinal use and also as ornamental plants. The different Passiflora speciesare host of a great diversity of arthropods that can cause injuries, economic damages and, in some situations, the plant death. Among the arthropods, leafhopper caterpillars are considered frequent and severe pests in the main passion fruit producing regions. The present work is an occurrence report of Isia alcumena and Spodoptera cosmioides attacking passion fruit plants (Passiflora edulis Sims) in the Federal District, Brazil. The S. cosmioides and S. eridania caterpillars were collected while consuming leaves of Passiflora edulis intra-specific hybrid located in the Germplasm Active Bank ‘Flor da Paixão’ at Embrapa Cerrados. The caterpillars of I. alcumena were collected on leaves of the Passiflora edulis cv. BRS Rubi do Cerrado at the Agricultural Support Unit, Embrapa Cerrados. After collected, the caterpillars were individualized in a breeding system with leaves of the host plants. The development of the caterpillar was accompanied until the emergence of the adults, which were identified and fixed in entomological pins for permanent dry preservation

    CARACTERIZAÇÃO MORFOLÓGICA DOS ESTÁGIOS IMATUROS DE Rachiplusia nu (GUENÉE, 1852) (LEPIDOPTERA: NOCTUIDAE: PLUSIINAE) E LISTA DE PLANTAS HOSPEDEIRAS

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    Rachiplusia nu (Guenée, 1852) é um noctuídeo cujas lagartas são vulgarmente conhecidas como “falsas-medideiras”. O hábito polífago e a voracidade das larvas têm tornado essa espécie uma das principais desfolhadoras de plantas cultivadas herbáceas no Sul do Brasil e em países do Cone Sul. Esse estudo teve como objetivo caracterizar a morfologia dos estágios imaturos de R. nu (Lepidoptera: Noctuidae: Plusiinae) e fornecer uma listagem atualizada das plantas hospedeiras. Os insetos foram coletados na localidade de Tuiuty em Bento Gonçalves (Rio Grande do Sul - Brasil) com o auxílio de armadilha luminosa. A criação foi conduzida sob as condições controladas 25 ± 1ºC, 70 ± 10% UR e fotofase de 14 horas. As lagartas foram alimentadas com dieta artificial e os adultos com solução de mel a 10%. Para caracterização morfológica foram preservados exemplares de cada fase de desenvolvimento em álcool 70%. Foi verificado na quetotaxia da lagarta que a cerda L3 nos segmentos torácicos T1, T2, T3, nos segmentos abdominais A1-A4, SD1 está presente acima da SD2, vertical a D2, apenas em A10 as cerdas L1, L2, L3, não foram localizadas. Foram registradas 56 espécies de plantas hospedeiras para R. nu pertencentes à 18 famílias botânicas

    Potencial reprodutivo de Spodoptera eridania (Stoll) (Lepidoptera: Noctuidae) em laboratório : efeito de múltiplos casais e do tamanho

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    Este estudo objetivou avaliar o efeito de confinar três casais em cada gaiola e o tamanho de adultos emergidos de pupas pequenas, medias e grandes (278,67 mg, 333,20 mg e 381,58 mg, respectivamente), sobre o potencial reprodutivo de S. eridania (Stoll, 1782), em condições controladas (25 ± 1 °C, 70% UR e 14 horas de fotofase). Avaliou-se a sobrevivência, o número de cópulas, fecundidade e fertilidade dos adultos. A sobrevivência não diferiu significativamente entre fêmeas provenientes de pupas de diferentes tamanhos, mas os machos oriundos de pupas grandes tiveram sobrevivência significativamente menor que os demais tamanhos. A fecundidade diferiu significativamente e correlacionou-se positivamente com o tamanho. O número de cópulas (espematóforos) e a fertilidade não variaram em função do peso pupal. Os resultados enfatizam a importância de indicar o número de cópulas e o tamanho dos insetos estudados para que comparações entre os parâmetros reprodutivos possam ser efetuadas.This study aimed to evaluate the effect of keeping three couples in the same cage, and the size of adults emerged from small, medium-sized and large pupae (278.67 mg; 333.20 mg and 381.58 mg, respectively), on the reproductive potential of S. eridania (Stoll, 1782) adults, under controlled conditions (25 ± 1 °C, 70% RH and 14 hour photophase). We evaluated the survival, number of copulations, fecundity and fertility of the adult females. The survival of females from these different pupal sizes did not differ statistically, but the survival of males from large pupae was statistically shorter than from small pupae. Fecundity differed significantly and correlated positively with size. The number of effective copulations (espematophores) and fertility did not vary significantly with pupal size. Our results emphasize the importance of indicating the number of copulations and the size of the insects when reproductive parameters are compared

    Noctuóides (Lepidoptera: Noctuoidea) associados a soja Bt e não-Bt no Cerrado brasileiro

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    O uso de OGM que expressam toxina Bt na produção de soja tem aumentado significativamente nos últimos anos no Brasil e são utilizados para conter os danos causados ​​pelos lepidópteros pragas. Neste estudo comparamos a riqueza e a abundância de Noctuoides (Noctuoidea) associados à soja Bt e não-Bt. Determinamos as variações temporais em função da fenologia e correlacionamos às variações populacionais das espécies mais comuns com variáveis ​​meteorológicas. A pesquisa foi conduzida na área experimental da Embrapa Cerrados. O método de coleta utilizado foi diferenciado sendo supressivo e absoluto. Um total de 13 espécies foram coletadas, das quais oito ocorreram em soja Bt. Os taxa mais representativos foram Chrysodeixis includens, Anticarsia gemmatalis e Spodoptera spp. O número de larvas pertencentes às espécies alvo da tecnologia Bt foram 10 vezes menores na soja Bt do que em soja não-Bt . Utetheisa ornatrix e Elaphria deltoides foram registradas na soja pela primeira vez, observando-se larvas de ambas espécies na soja não-Bt e as de U. ornatrix também na soja Bt. Somente as larvas de A. gemmatalis se correlacionaram (p <0,05) negativamente com a precipitação. Este estudo forneceu informações em campo sobre a abundância e riqueza de espécies na soja não- Bt, associada aos efeitos da soja Bt. A importância do monitoramento das lagartas é substancial, a fim de tomar a melhor decisão de controle, considerando-se os diferentes níveis de infestação entre cultivares como critério.The use of GMO expressing Bt toxin in soybean production has increased significantly in the last years in Brazil in order to manage the damage caused by lepidopteran pests. In this study, we compared the richness and abundance of owlet moths (Noctuoidea) associated with Bt and non-Bt soybean. We determined the temporal variations as a function of phenology, and correlated the population variations of the most common species with meteorological variables. The research was conducted at the experimental area of Embrapa Cerrados. The collection method used was differentiated being suppressive and absolute. A total of 13 species were collected, of which eight occurred on Bt soybeans. The most representative taxa were Chrysodeixis includens (72.87%), Anticarsia gemmatalis (18.17%) and Spodoptera spp (5.22%). The number of larvae belonging to species targeted by the Bt technology was 10 times lower on Bt than on non-Bt soybeans. Utetheisa ornatrix and Elaphria deltoides were recorded on soybean for the first time, observing larvae of both species in non-Bt soybean and those of U. ornatrix also in Bt soybean. Only A. gemmatalis larvae correlated (p <0.05) negatively with precipitation. This study provided field information on the abundance and species richness of owlet moths on non-Bt soybeans, associated with the effects of Bt soybean. When considering the different levels of infestation between cultivars as a criterion, larvae monitoring is of substantial importance in order to develop the lost control program
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