Possible effects of Ultraviolet ray (UV-C) on biological traits of Callosobruchus maculatus (Col.: Chrysomelidae)

摘要

Cowpea seed beetle, Callosobruchus maculatus (F.) (Col.: Chrysomelidae), is one the most important pests of stored products worldwide, which specially distributed in the tropical and subtropical regions. In the present study, effects of different irradiation times of Ultraviolet ray (0,10, 20, 30, 40 and 50 min) on the most important biological traits of this pest were evaluated under laboratory conditions. Our findings revealed that different irradiation times significantly affect mortality of immature stages of C. maculatus. The UV-C irradiation had no significant effects on duration of different life stages of this pest. Population growth parameters of C. maculatus were significantly affected by different treatments. The highest and lowest recorded values for net reproductive rate (R-0) were calculated at Control (38.70 offspring) and 50 min of irradiation (10.36 offspring), respectively. The calculated values for intrinsic rate of increase (r) at different treatments were significantly decreased with increasing irradiation time. The lowest value of this parameter was obtained at 40 min of irradiation (0.058 day(-1)) and followed by 50 min (0.061 day(-1)), while the highest value was recorded at Control (0.096 day(-1)). Sex ratio of C maculatus was not significantly affected at different treatments. The results of the present study can be used for further assessment of irradiation as a means to control C maculatus. (C) 2016 Published by Elsevier Ltd.