Temperature and Host Plant Impacts on the Development of Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae): Linear and Nonlinear Modeling

The tobacco cutworm, Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae), is one of the most serious pests in field crops, vegetables, and ornamentals. Temperatures (15, 20, 25, 27, 30, 35, and 40 ffiC), host plants (soybean (Glycine max (L.)), maize (Zea mays L.), groundnut (Arachis hypogaea L.) and azuki bean (Vigna angularis (Willd.) Ohwi & H. Ohashi,), and the artificial diet-dependent developmental parameters and survival of S. litura were examined in this study. Stage-specific parameters such as threshold development temperature (LDT) and thermal constant (K) (Degree day (DD)) were determined by linear and nonlinear models (Sharpe-Schoolfield-Ikemoto), respectively. The total developmental time (egg-adult) decreased with increasing temperature on host plants and with an artificial diet. The total immature developmental time varied from 106.29, 107.57, 130.40, 111.82, and 103.66 days at 15 ffi C to 22.47, 21.25, 25.31, 18.30, and 22.50 days at 35 degrees C on soybean, maize, groundnut, azuki bean, and artificial diet, respectively. The LDT for the total immature completion was 7.50, 9.48, 11.44, 12.32, and 7.95 degrees C on soybean, maize, groundnut, azuki bean, and artificial diet, respectively. The K for the total immature completion was 587.88, 536.84, 517.45, 419.44, and 586.95 DD on soybean, maize, groundnut, azuki bean, and artificial diet, respectively. Temperature and host plant interaction also influenced the longevity and survival of adults. The findings of this study can be used to predict the number of generations, spring emergence, and population dynamics of S. litura. The nutrient content analysis of the host plants is discussed in terms of the developmental patterns of S. litura.