Yellow meal worm (Tenebrio molitor L.) development time of life stages duration and survival rate at different temperatures in laboratory conditions

Abstract

The yellow mealworms (Tenebrio molitor L.) is one of the most valuable and high-nutritional food insects that is used in the animal and human feed industry. In the current study development time of eggs, larvae, pupa, and the entire immature stage, at five constant temperatures of 20, 23, 25, 27, and 30 oC (+-1), 60+-10% RH was examined under laboratory conditions. The eggs in the same age (less than 24 hours) were randomly selected. The growth was completed at all temperatures of the test. Data showed that the developmental times of males or females on each variety at various constant temperatures differed significantly. The regression and Ikemoto and Takailinear models, in the absence of 27 oC described the relationship of developmental rate to temperature for males and females of T. molitorvery well. Data were fitted to various nonlinear temperature-dependent models. The model of Lactin-1 and Janisch/Rochat have the best estimate for Tu about 36.79 and 37.36 oC. Development time of immature stage was 203.70+-2.65, 170.71+-3.51, 143.07+-2.29, 111.31+-0.81 day. The longest development time was recorded at 20 oC and the shortest growth period at 27 oC. The results of the variance of the data showed that the development time of the immature stages at different temperatures at a 5% probability level was significant. Although by the increasing in temperature from 20 to 27 development time was declined but that was not associated with increased growth rates.