Effect of temperature on the biology and thermal requirements of Pseudaletia sequax (Lop.: Noctuidae), on artificial diet.

Estudou-se o efeito de seis temperaturas constantes (18, 20, 22, 26, 30 e 32ºC), na biologia das fases imaturas de Pseudalesia sequax Franclemont, 1951 (Lep.: Noctuidae), criada em dieta artificial. Parâmetros da fase adulta também foram avaliados nos regimes térmicos de 25 ± 2ºC e 28 ± 2ºC. A sobrevivência e a duração das fases de ovo, lagarta e pupa, bem como o peso da popa, foram afetados pela temperatura. Na faixa de 20 a 30ºC para a fase de ovo e de 18 a 30ºC para as fases larval e pupal, a duração do desenvolvimento decresceu com o aumento da temperatura. A longevidade, a duração do período de pré-oviposição e a capacidade de postura foram afetadas pela temperatura, sendo que o regime térmico de 25 ± 2ºC foi mais adequado à espécie do que o de 28 ± 2ºC. A temperatura-base (Tb) e a constante térmica (K) foram de 8,1ºC e 84,4 GD) para a fase de ovo, 8,8ºC e 505,9 GD para a fase larval, 12,5ºC e 180,6 GD para a fase pupal e de 9,1ºC e 804,4 GD) para todo  o período de desenvolvimento. A condição térmica mais adequada para a criação de P. sequax é entre 25 e 26ºCThe effect of six temperatures (18, 20, 22, 26, 30 e 32ºC) on the biology of immature stages of Pseudaletia sequax Franclemont, 1951 (Lep.: Noctuidae), was studied in laboratory, on artificial diet. The adult parameters were also evaluated at 25 ± 2ºC and 28 ± 2ºC. The viability and the length of embrionary, larval and pupal stages, and the pupal weight was affected by the temperature. The length of development decreased with the increase of temperature of 2010 30ºC for the eggs, and 18 to 30ºC for larvae and pupae. As for the adults, the temperature affected the longevity, the preoviposition and oviposition periods as well as the capacity of laying eggs; the thermal condition of 25 ± 2ºC was more suitable than the 28 ± 2ºC one. The values for base temperature (Tb) and K were, respectively, 8,1ºC and 84,4 GD for the egg stage, 8,8ºC and 505,9 GD for the larval stage, 12,5ºC and 180,6 GD for the pupal stage, and 9,1ºC and 804,4 GD during all the period of development. The most adequate thermal condition for rearing this species was found to be between 25 and 26º

Performance of Pseudaletia sequax (Lep.: Noctuidae) in natural and artificial diels

Estudou-se o desempenho de Pseudaletia sequax Franc., 1951 (Lep.: Noctuidae  em folhas de trigo e em três dietas artificiais, sob condições controladas de temperatura (25 ± 20ºC para as fases imaturas e 23 - 30ºC para os adultos), umidade relativa do ar (60 ± 10%) e fotófase (14 horas). O alimento ingerido pelas lagartas influenciou a viabilidade das fases de ovo, lagarta e pupa, a duração dos períodos larval e pupal e o peso da pupa. Foram identificadas duas dietas artificiais, urna à base de feijão, caseína, farinha de soja, genne de trigo e levedura de cerveja, e outra à base de feijão, germe de trigo e levedura de cerveja; ambas podem ser utilizadas em substituição às folhas de trigo para a criação de P. sequax.Pseudaletia sequax Franc., 1951 (Lep.: Noctuidae) was studied on wheat leaves and on three artificial dieta, in laboratory under controlled conditions (temperature: 25 ± 20ºC for the immature stages and 23 - 30ºC to the adults; air moisture: 60 ± 10%; photophase: 14 h). The food ingested during the larval stage affected the viability of eggs, larvae and pupae, the length of larval and pupal stages and pupal weight. Two artificial diets were the most suitable: one composed by beans, casem, soybean flour, wheat germ and yeast, and other composed by beans and wheat germ and yeast only; both dieta may substitute the natural diet, i.e., wheat leaves for P. sequax rearin

Estrutura e sistema de aeração do cupinzeiro de Cornitermes cumulans (Kollar, 1832) (Isoptera: Termitidae)

This paper deals with the nest structure and aeration system of Cornitermes cumulans (Kollar, 1832) (Isoptera, Termitidae), an important insect pest species existing in areas requiring mechanization. The structure was studied by cutting longitudinal intersections of the nest. The aeration system was analyzed by using a motorized thermonebulizator and a powder insufflator. The results indicated that the powder injection process did not provide information as to the structures involved with aeration. However, the tog produced by the thermonebulizator showed to be efficient to demonstrate the importance of the cavity that surrounds the nest base, in the aeration. Estudou-se a estrutura do ninho e o sistema de aeração do cupim de montículo, Cornitermes cumulans (Kollar, 1832), importante espécie de praga existente em áreas de cultivo que exigem mecanização. Para o estudo da estrutura promoveu-se o corte longitudinal para que cada parte do ninho fosse analisada. Para o estudo do sistema de aeração empregou-se um aparelho termonebulizador e um insuflador de pó, com o propósito de detecção e demarcação, respectivamente, das estruturas envolvidas no sistema de aeração do ninho. Os resultados mostraram que o processo da injeção de pó no interior do ninho não trouxe informações precisas na demarcação das estruturas envolvidas com a aeração; no entanto, a fumaça produzida pelo termonebulizador mostrou-se eficiente para demonstrar o importante papel da cavidade, que circunda a base do ninho, na aeração

Occurrence of Aceria tosichella in Brazil

O objetivo deste trabalho foi avaliar a ocorrência de Aceria tosichella Keifer (Prostigmata: Eriophyidae), ácaro-do-enrolamento-do-trigo, no Rio Grande do Sul. Amostras para detectar espécimes de A. tosichella foram coletadas em lavouras de trigo, milho e aveia e em potenciais gramíneas hospedeiras em 46 localidades, em outubro de 2006 e em agosto e outubro de 2007. Amostras de trigo tambÚm foram coletadas em casas de vegetaþÒo na Embrapa Trigo, Passo Fundo, RS. EspÚcimes de A. tosichella foram encontradas em amostras de trigo de Passo Fundo, Palmeira das Missões, São Luís Gonzaga e Santo Antonio das Missões. Sintomas de infestação de A. tosichella foram observados somente em condições de casa de vegetação. Este é o primeiro registro de A. tosichella no Brasil e o segundo na América do Sul.The objective of this work was to evaluate the occurrence of Aceria tosichella Keifer (Prostigmata: Eriophyidae), the wheat curl mite, in Rio Grande do Sul, Brazil. Samples to detect A. tosichella specimens were collected in wheat, corn, oat crops and potential host grasses in 46 localities, in October 2006, August and October 2007. Samples of wheat were also collected in experimental greenhouses at Embrapa Trigo, Passo Fundo, RS, Brazil. A. tosichella specimens were found in wheat samples from Passo Fundo, Palmeira das Missões, São Luís Gonzaga, and Santo Antônio das Missões, RS, Brazil. Symptoms due to A. tosichella infestations were observed only in greenhouse conditions. This is the first report of A. tosichella in Brazil and the second in South America

Performance of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) larvae in different food sources

Recently observed in Brazil, Helicoverpa armigera became a relevant pest due to its rapid spread and the economic importance of crops in which it has established, such as soybean and maize. Understanding its establishment process in different regions and production systems, as well as the population dynamics of a polyphagous pest, as the basis for its management, depends on the knowledge of the effect of plant species as food sources on the pest biology. A laboratory experiment was conducted, supplying the caterpillars with reproductive organs of soybean, maize, canola, black oat, oat, turnip and ryegrass. It was concluded that the different food sources affect the larval development of H. armigera. Maize and wheat ears and canola siliques are the best food sources for the development of H. armigera. Ryegrass ears, on the other hand, are the worst ones. Black oat and oat panicles and turnip siliques are less suitable than soybean pods as food sources for the caterpillars

Performance of helicoverpa armigera larvae on leaves of plant species / Desempenho de larvas de helicoverpa armigera em folhas de espécies vegetais

Helicoverpa armigera (Hübner) (Lep.: Noctuidae) has established itself as a soybean pest in southern Brazil; however, as a polyphagous species, the caterpillar has been found in other economically important crops and even uncultivated plants. The nutritional value of host plants as food sources influences biological performance, which can interfere with population dynamics and pest management. In this sense, an experiment was carried out to assess the effect of different foods on biological aspects and larval consumption. Eight plant species were evaluated, including cultivated plants, ground cover plants, and weeds. Soybean, where caterpillars acquired greater importance as a pest, was considered the standard food. The plants were grown in pots in a greenhouse, and the leaves were harvested to feed the larvae as they hatched. The findings show that H. armigera larvae fed on canola or radish leaves exhibit biological performance comparable to that fed on soybean. The larvae did not survive when fed ryegrass, horseweed, corn, or wheat

Wheat cultivars response to Rhopalosiphum padi infestation

O objetivo deste trabalho foi avaliar a resposta de oito cultivares comerciais de trigo (BRS 194, BRS 208, BRS Camboatá, BRS Guabiju, BRS Guamirim, BRS Louro, BRS Timbaúva e BRS Umbu) à infestação do pulgão Rhopalosiphum padi (Hemiptera: Aphididae). O experimento foi realizado na Embrapa Trigo, em telado, em blocos ao acaso, com oito tratamentos e seis repetições, dispostos em parcelas subdivididas. As parcelas principais receberam os tratamentos com e sem infestação de pulgões, e as subparcelas foram compostas pelas cultivares. A infestação com os pulgões (20 adultos ápteros por planta) foi realizada aos 12 dias após a emergência das plantas, quando se encontravam no início do afilhamento, e foi mantida durante 15 dias. As cultivares avaliadas responderam diferentemente à infestação do pulgão R. padi. A cultivar BRS Timbaúva é a mais resistente, e as cultivares BRS Umbu e BRS Guabiju são as mais suscetíveis ao pulgão, quanto ao crescimento e a capacidade produtiva de plantas.The objective of this work was to evaluate the response of eight commercial wheat cultivars (BRS 194, BRS 208, BRS Camboatá, BRS Guabiju, BRS Guamirim, BRS Louro, BRS Timbaúva e BRS Umbu) to the infestation of Rhopalosiphum padi (Hemiptera: Aphididae). The experiment was carried out at Embrapa Trigo, in greenhouse conditions. It was used the randomized block design, in a split-plot array, with eight treatments and six replicates. The plots received treatments with or without infestation with aphids, and the split-plots were composed by the cultivars. The infestation with aphids (20 wingless adults per plant) was done 12 days after plant emergency, in the beginning of tillering, and was kept for 15 days. The cultivars responded differently to the infestation with aphids. BRS Timbaúva cultivar is more resistant, and BRS Umbu and BRS Guabiju cultivars are more susceptible to R. padi, concerning plant growth and plant yield

Agronomic performance, chromosomal stability and resistance to velvetbean caterpillar of transgenic soybean expressing cry1Ac gene

O objetivo deste trabalho foi analisar a performance agronômica e a estabilidade cromossômica de progênies transgênicas homozigotas de soja [Glycine max (L.) Merrill.], e confirmar a resistência dessas plantas a Anticarsia gemmatalis. Onze progênies com expressão dos genes cry1Ac, hpt e gusA foram avaliadas quanto às características agronômicas, em relação à cultivar parental IAS 5 não transformada. Análises citogenéticas foram realizadas em plantas transgênicas e não transgênicas. Duas das 11 progênies transgênicas também foram avaliadas quanto à resistência a A. gemmatalis, em bioensaios in vitro e in vivo. Dois controles negativos foram utilizados nos bioensaios: uma linha transgênica homozigota, com apenas o gene repórter gusA, e plantas de 'IAS 5' não transgênicas. A presença do transgene cry1Ac não afetou nem o desenvolvimento nem a produtividade das plantas. As plantas transgênicas apresentaram cariótipo normal. No bioensaio com folhas destacadas, as plantas cry1Ac exibiram completa eficácia contra A. gemmatalis, enquanto os controles negativos foram significativamente danificados. Ensaios com plantas inteiras confirmaram a elevada proteção do cry1Ac contra a lagarta-da-soja, enquanto as plantas 'IAS 5' não transgênicas e a linha homozigota gusA exibiram 56.5 e 71.5% de desfolhação, respectivamente. A presença do transgene cry1Ac não afeta a performance agronômica da soja (incluindo a produtividade) e confere elevada proteção a A. gemmatalis.The objective of this work was to analyze the agronomic performance and chromosomal stability of transgenic homozygous progenies of soybean [Glycine max (L.) Merrill.], and to confirm the resistance of these plants against Anticarsia gemmatalis. Eleven progenies expressing cry1Ac, hpt and gusA genes were evaluated for agronomic characteristics in relation to the nontransformed parent IAS 5 cultivar. Cytogenetical analysis was carried out on transgenic and nontransgenic plants. Two out of the 11 transgenic progenies were also evaluated, in vitro and in vivo, for resistance to A. gemmatalis. Two negative controls were used in resistance bioassays: a transgenic homozygous line, containing only the gusA reporter gene, and nontransgenic 'IAS 5' plants. The presence of cry1Ac transgene affected neither the development nor the yield of plants. Cytogenetical analysis showed that transgenic plants presented normal karyotype. In detached-leaf bioassay, cry1Ac plants exhibited complete efficacy against A. gemmatalis, whereas negative controls were significantly damaged. Whole-plant feeding assay confirmed a very high protection of cry1Ac against velvetbean caterpillar, while nontransgenic 'IAS 5' plants and homozygous gusA line exhibited 56.5 and 71.5% defoliation, respectively. The presence of cry1Ac transgene doesn't affect the majority of agronomic traits (including yield) of soybean and grants high protection against A. gemmatalis