Bioecologia de Alabama argillacea I. Biologia em diferentes temperaturas, na cultivar de algodoeiro IAC-17

This research was carried out in order to study the biology of Alabama argillacea Hübner (1818) (Lepidoptera, Noctuidae) at constant temperatures of 20, 25, 30 and 35°C. This study was conducted in climatic chambers under relative humidity of 60 ± 10% and 14 hour photoperiod. Cotton-leaves of the cultivar IAC-17 were used as natural diet. A shortening of the larval period was observed as temperature increased from the 20 to 30°C. There was a variation between the number of instars of the cotton leafworm, and the temperature. There was no correlation between the number of instars and the size of the larvae. The pupal period decreased as temperature increased in the 20 - 30°C range. The optimum for oviposition ranged from 25 to 30°C and there was no oviposition at 20°C and 35°C. A complete life cycle was 26.88 and 17.83 days respectively at 25 - 30°C (optimum range for development). Regression equations for the different phases of the life cycle of the cotton leafworm in relation to temperature were determined.Estudou-se a biologia de Alabama argillacea Hübner (1818) (Lepidoptera, Noctuidae) em folhas de algodoeiro da cultivar IAC-17, utilizando-se câmaras climatizadas mantidas a 20, 25, 30 e 35°C, com umidade relativa de 60 ± 10% e fotófase de 14 horas. Observou-se que há um encurtamento do período larval com a elevação térmica, dentro da faixa de 20 a 30°C. O número de instares foi variável com a temperatura, mas não houve correlação entre ele e o comprimento das lagartas. Também a duração do período pupal decresceu com o aumento de temperatura, dentro da faixa de 20 - 30°C. A 20 e 35°C não ocorreram posturas, sendo que o ciclo total (ovo a adulto) foi de 26,88 e 17,83 dias respectivamente, quando o inseto foi mantido a 25 e 30°C (faixa favorável de desenvolvimento). Observou-se que, em função da elevação de temperatura, ocorreu um encurtamento do ciclo, dentro da faixa de 20 - 30°C. Foram determinadas equações de regressão simples para as diferentes fases do ciclo biológico do inseto, com relação à temperatura

Bioecologia de Alabama argillacea II. Evolução populacional em seis regiões do Estado de São Paulo, com base em suas exigências térmicas

The cotton leafworm (Alabama argillacea Hübner (1818) has, each year, a constant period of occurence during the cotton growing season, in the State of São Paulo, Brazil. Surveys with light traps in six localities of the State (Assis, Campinas, Mococa, Piracicaba, Ribeirão Preto and Valinhos) were made in order to find out those periods. With its thermal requirements it was possible to know the number of its generations all through the year in order to provide basic data concerning this pest, as a prediction of its outbreak, and for improving control procedures in the crop. The thermal requirements of the cotton leafworm were determined based on the biological results obtained in climatic chambers set at 20, 25, 30 and 35°C (60 ± 10% relative humidity and a 14-hour photoperiod) with IAC-17 cultivar leaves. The threshold of development for the egg, larval, pre-pupal and pupal phases was calculated by the coefficient of variation method; values of 12.6; 9.3; 14.9 and 13.5°C, respectively, were found. The formula for obtaining those thermal requirement data was: K = y (t - a). Values of 37.20, 195.97, 10.10 and 110.35 degree-days for the phases of egg, larva, pre-pupa and pupa, respectively, were obtained. Basing on the total sum of degree-days per "péntada" for the six localities, two to seven generations per year may occur.O curuquerê-do-algodoeiro (Alabama argillacea Hübner (1818) tem uma época definida de surto nas diferentes áreas do Estado de São Paulo. Tomando-se por base levantamentos realizados com armadilhas luminosas nas regiões de Assis, Campinas, Mococa, Piracicaba, Ribeirão Preto e Valinhos, determinou-se, em função destas épocas de seu aparecimento e das suas necessidades térmicas, o provável número de gerações desta praga nestas áreas durante o ano, numa tentativa de prever e controlar a sua evolução populacional dentro da cultura. As necessidades térmicas do curuquerê foram determinadas com base nos resultados biológicos obtidos em câmaras climatizadas reguladas a 20, 25, 30 e 35°C (UR de 60 ± 10% e fotófase de 14 h), com folhas da cultivar IAC-17, estimando-se a temperatura-base para as fases de ovo, lagarta, pré-pupa e pupa, pelo método do coeficiente de variação e encontrando-se valores, respectivamente, de 12,6; 9,3; 14,9 e 13,5°C. A constante térmica em graus dias (GD)foi estimada pela fórmula K = y (t - a), sendo obtidos os valores de 37, 20 GD, 195,97 GD, 10,10 GD e 110,35 GD para as fases de ovo, lagarta, pré-pupa e pupa, respectivamente. A partir destes resultados e de graus dias acumulados por pêntada, utilizando-se as normais de cada localidade, estimou-se que o número de gerações pode variar de duas a sete para as regiões analisadas

Multiple Signals Converge on a Differentiation MAPK Pathway

An important emerging question in the area of signal transduction is how information from different pathways becomes integrated into a highly coordinated response. In budding yeast, multiple pathways regulate filamentous growth, a complex differentiation response that occurs under specific environmental conditions. To identify new aspects of filamentous growth regulation, we used a novel screening approach (called secretion profiling) that measures release of the extracellular domain of Msb2p, the signaling mucin which functions at the head of the filamentous growth (FG) MAPK pathway. Secretion profiling of complementary genomic collections showed that many of the pathways that regulate filamentous growth (RAS, RIM101, OPI1, and RTG) were also required for FG pathway activation. This regulation sensitized the FG pathway to multiple stimuli and synchronized it to the global signaling network. Several of the regulators were required for MSB2 expression, which identifies the MSB2 promoter as a target “hub” where multiple signals converge. Accessibility to the MSB2 promoter was further regulated by the histone deacetylase (HDAC) Rpd3p(L), which positively regulated FG pathway activity and filamentous growth. Our findings provide the first glimpse of a global regulatory hierarchy among the pathways that control filamentous growth. Systems-level integration of signaling circuitry is likely to coordinate other regulatory networks that control complex behaviors