در تغذيه از مغز پسته PLODIA INTERPUNCTELLA )HUBNER( اثرات رقابت درون گونه اي بر رشد، توليد مثل و بقاي شب پره هندي

Effects of Intraspecific Competition on Growth, Reproduction and Survival of Indian Meal Moth, Plodia interpunctella (Hubner), feeding on Pistachio Kernels

In this research, potentials of growth and reproduction of Indian meal moth was assessed in an experimental treatments consisting different levels of intraspecific competition (e. g. seven densities of 20, 40, 60, 80, 100, 150 and 200 eggs in each treatment containing equal amounts of pistachio kernels from Badami cultivar) in the laboratory condition at 25±1°C, 60±5% R.H. and a photoperiod of 16:8 h (L:D) during 2002-2003. Then, the effects of population density on the growth, reproduction and mortality of egg, larvae, pupae and adults were assessed. Results indicated that the competition pattern of Indian Meal Moth is Scramble type competition and effects of this type of competition in density-dependent manner caused the asynchrony in completing the life span (mean emerging period of 21 days at highest density and 12 days at lowest ones) and also decrease adults reproduction emerging in that plots (mean of 83.2 eggs at highest density and 165.5 eggs at lowest ones). In addition, competition among larvae of this pest by means of increasing the number of contacts, caused inhibition of feeding and also cannibalism phenomenon in larvae on each other and on eggs and pupae (93.1%total mortality at highest density and 34% at lowest one). Higher levels of population density with acceleration in competition effects led to sever mortality rates in the pest. It was concluded that occurring high-density levels of population of this pest in feeding from pistachio kernels, will more accelerate cannibalism specially on the first instars by feeding on each other and on available eggs, in comparison to the other instars.