HISTOPATHOLOGICAL EFFECT OF CERTAIN HEAVY METALS ON THE MOSQUITO VECTOR CULEX PIPIENS L. (DIPTERA: CULICIDAE)

In the laboratory, histopathological effects of heavy metals in the form of cadmium chloride, copper sulphate, lead nitrate and mercuric nitrate were tested against the adults resulted from the 2nd larval instar of C. pipiens treatment with the LC50s (0.11, 5.1, 45.4 and 0.44ppm ) to study their effect on certain histological organssuch as ovary, testis and fat body. The histological examinations of ovaries in heavy metals-treated C. pipiens females showed a reduction in the number of developed oocytes and degeneration of a great number of oocytes. The highest reduction and damage were induced by Cd and Hg. The present study also showed damage and reduction in spermatogonia and spermatocytes in heavy metals-treated C. pipiens males. The highest reduction and abnormality were caused by Cd and Hg. In addition, the present study showed alteration and abnormality of fat body in heavy metals-treated mosquitoes.It is clear from the results obtained in this study that the presence of such elements in the ecosystem water for Culex mosquitoes as possible to contribute to the reduction of mosquito breeding.