Ecological and Toxicological Studies on the Mosquitoes from Jazan Region in Saudi Arabia

Abstract

The present study was undertaken during the period from February 2009 to September 2010 to survey the different species of mosquitoes in Jazan province, study the distribution, prevalence as well as abundance of that mosquitoes species. Also evaluate the effect of climatic factors governing the distribution of mosquitoes. The prevalent mosquito, Cx. pipiens, was chosen to treat with some natural products to evaluate the biological aspects (larval, pupal and adult mortalities percent as well as larval, pupal and adult durations also the growth index, total inhibition and malformations) against it. Seven genera and 16 species of mosquitoes are reported in Jazan region. Cx. pipiens and Cx. tritaeniorhynchus were the most prevalent mosquitoes, distributed in (90 % and 80 % of the total localities respectively) whereas Am. vexans was reported as the most abundant mosquito species recording 56.9 % of the total collected mosquitoes. Mosquitoes were available throughout the year, but at different densities depending significantly(P>0.01, r= 0.459) on the rain fall rate as two peaks of mosquito activity were attained yearly, February – April and July – September, in the frequently visited sites but mosquitoes activity was increased in occasionally visited sites in Winter than that of Summer. Different tested plant products induced toxic effects on different stages of Cx. pipiens but in different percent. They revealed Lc50 of 13.6, 658.39 and 5991.5 ppm for rotenone, limonine and jojoba oil respectively.