EFFECTS OF GAMMA RADIATION ON THE ACTIVITY OF THE. MOSQUITO CULEX PIPIENS L. I. EFFECTS ON THE ATTRACTION OF THE MOSQUITO TO LIGHT, COLOURS AND HOST

The present work was carried out to investigate the effects of gamma radiation at three doses: 40, 80 and 120 Gray. On the response of the adult mosquito Culex pipiens complex when irradiated in the larval, pupal or adult stage, to the surrounding environmental factors as light, colour and host. There was no effect of any of the doses applied on the response of both sexes of the adult mosquito to light whether the irradiation was applied at the larval or the pupal stages. When the adult females were irradiated at 120 Gray there was a significant decrease in its response when compared to control females. The colour preference of the control adults was in the order, pink, green, yellow, blue (the least preferable). When adults were irradiated in the larval stage at 40 Gray they preferred the pink colour. While when they were irradiated in the pupal stage at 40 Gray, the males preferred the green colour while the females preferred the pink colour, the blue colour still the least preferable. At _so and 120 Gray both males and females preferred the pink colour and the blue was the least preferable too. When adults were irradiated at 40 Gray the pink colour was preferable and the blue was still less preferable. However with increasing the dose to 80 and 120 Gray, the attraction to the blue colour was increased and that to the pink colour was decreased. There was no significant effect on the response of the females to host when they were irradiated in the larval stage at 40 Gray. However there were significant decreases in the attraction of females to host when they were irradiated in the pupal stage at high doses tested. When newly emerged adults were irradiated with 40 Gray no significant effect was observed on the female response to host, while at 80 and 120 Gray there was a significant reduction.