Effect of Temperature and Relative Humidity on the Growth and Development of Acridid Grasshopper, Chrotogonus trachypterus Blanchard

Growth and development of acridid grasshopper, Chrotogonus trachypterus Blanchard was greatly influenced by different levels of temperature (20, 25, 30, 35 and 37oC) and relative humidity (40, 60 and 70%). A laboratory study was revealed that temperature between 30-35oC with 60% relative humidity is mostly suitable for life cycle of the test insect. Maximum oviposition period was 54.6±2.21 days at 25oC whereas, maximum hatching percent was recorded at 30oC (90.6±1.18). Average fecundity of a female increased with the increase in temperature up to 35oC (242.1±2.55) but decreased at 37oC. Developmental period of nymphs was longer at 20oC as 94.03±3.45 and 105.3±3.16 days for males and females whereas, nymphs quickly developed at 37oC within 50.3±0.55 and 60.2±2.44 days, respectively. Highest survivability was obtained at 25o and 30oC. Relative humidity ranged from 60-70% gave non-significant differences and found to be most suitable for insect growth. Study of interaction of ecological factors will be helpful in management strategy of the pest and future adaptation behavior and outbreak issues.