Abstract

Investigations were carried out to assess the spatial flight pattern and movement of three stored grain insect pests in storage godown using sticky traps. Significant variations of Tribolium castaneum (Herbst) trap catches were registered on different height and trapping periods. The traps placed at a height of 18 feet recorded the highest mean trap catches of T. castaneum (341.3 / trap) followed by 15 feet height (202 / trap) and catches between 6 PM – 10 AM were the highest mean trap catches of T. castaneum, which ranged from 73.7 to 341.3. Whereas, 4 PM – 6 PM registered 46.3 to 195.7 numbers per trap. The maximum mean trap catches of Cryptolestes ferrugineus (Stephens) was observed at a height of 3 feet from the ground level and ranged from 1.7 to 12.0 numbers per trap for different trapping period. Among the trapping period, the period between 4PM – 6PM recorded the maximum mean trap catches (12 / trap). There were no significant differences of mean trap catches of Ephestia cautella (Walker) on different height intervals and trapping period. Very low number of E. cautela was trapped throughout the study period and the mean trap catches ranged from 0.3 to 2.0 per trap. The trap placed at a height of 18 feet and late evening hours of 6 PM to 10 AM accounted for the maximum mean trap catches (2.0 / trap). The independent variable temperature exerted a significant influence on movement of T. castaneum and C. ferrugineus and showed that one degree rise in temperature could reduce the trap catches by 3.15 and 4.41 numbers, respectively. However, the relative humidity showed significant influence on movement of T. castaneum and E. cautella and revealed that one per cent of relative humidity could increase the trap catches by 3.29 and 2.99 numbers, respectively.

Keywords: Spatial flight pattern, Storage pests, Tribolium castaneum, Cryptolestes ferrugineus, Ephestia cautella, Sticky trap, Storage godown