Temperature Effects on the Immature Development Time of Culex eduardoi Casal & García (Diptera: Culicidae)

The effect of constant temperatures on the development time from first instar to adult emergence was studied in Culex eduardoi Casal & García reared at 7, 10, 15, 20, 25, 30 or 33°C. Data were adjusted to the linear degree-day model and the nonlinear Briére model. According to the linear model, the development time was inversely related to the rearing temperatures between 7°C and 25°C. Maximum mortality (100 percent) was recorded at temperatures > 30°C. According to the linear model, the development threshold temperature and thermal constant were 5.7°C and 188.8 degree days, respectively. The lower and upper threshold temperatures and the optimum temperature for the nonlinear model were -2.3, 30.0 and 28.1°C, respectively.

An adapted thermal-gradient block for the germination of photoblastic seeds

This work describes an adapted thermal-gradient block with internal illumination, allowing experiments with light-requiring seeds. The temperature dependence study on the germination of the photoblastic Plantago tomentosa seeds was carried out in order to test the performance of the apparatus. With the aid of the model described here, some parameters related to the response of the seeds to temperature could be estimated, showing that the apparatus was suitable for the studies on the temperature dependence of photoblastic seeds.

Este trabalho descreve um bloco termo-gradiente com iluminação interna, adaptado para estudos com sementes que requerem luz para germinar. Para se aferir o desempenho do equipamento, este foi usado num experimento sobre o efeito da temperatura na germinação de sementes fotoblásticas de Plantago tomentosa. Com o protótipo aqui descrito, alguns parâmetros da resposta dessa semente à temperatura puderam ser estimados, mostrando que o equipamento pode ser usado em estudos sobre a dependência térmica da germinação de sementes fotoblásticas.