Incidence, Infestation and Role of Weather Factors in Regulating the Population of Flea Beetle (Altica hemensis) on Soybean under Temperate Conditions

Abstract

Pulses have a strong history of nourishing human beings for centuries together. Soybean (G. max) being an important pulse crop, became vulnerable to a number of insect pests, viz., flea beetle (A. hemensis), pod borer (H. armigera), etc. Since in Kashmir through its intensive cultivation the acreage and production of the crop steadily increased, it is imperative to study the population buildup of the major insect-pests attacking soybean. The incidence of flea beetle, Altica hemensis commenced from 27th Standard meteorological week (SMW) with an average population level of 0.48 beetles per three leaves per plant reached its peak level of 1.75 beetles in 32nd SMW and then decreased and reached 0.24 beetles in 40th SMW. The percentage of flea beetle, A. hemensis infestation ranged from 8-40%, with highest infestation recorded in 33rd and 34th SMW respectively. The incidence of flea beetle revealed positive correlation with maximum temperature (r = 0.45), minimum temperature (r = 0.87), morning relative humidity (r = 0.39), evening relative humidity (r = 0.68) and negative correlation with rainfall (r = - 0.41) and sunshine hours (r = - 0.19). The regression analysis revealed that 88 per cent of flea beetle, A. hemensis population was influenced by weather parameters.