الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
a) Among ten mosquito larval species recorded in the State of Kuwait Culex pipiens complex larvae are the prevailing species in the country constituting more than 90 of the total mosquito larval species in the country. Cx. pipiens complex in the State of Kuwait exhibits homodynamicity and breeds and flourish readily in different types of breeding sites particularly in agricultural and animal husbandry farms followed by urban and semi-urban areas as well as border and sea ports. Chemical mosquito larval control has been the main tool adopted by insect control teams of Ministry of Health in the country since, 1975. Hence, in many countries as well as in the State of Kuwait there has been increased interest in using new biocides in mosquito larval control. Before adoption of such strategy in the country under the local environmental conditions, comparative laboratory and field studies to evaluate chemical and biological agents in Cx. pipiens complex larval control have been performed. In the present study the larvicidal action of temephos, dimilin, and toxins producing mosquitocidal bacilli, Bacillus thuringiensis israelensis (B. t. i.) and Bacillus sphaericus (B. s.) (tablets and ABG formulations) were investigated in details under both laboratory (susceptiblility tests) and field conditions in agricultural and animal husbandry farms area (Al-Wafra) with high density of Cx. pipiens complex the prevailing species in the area. Associated arthropods and others organsims with mosquito larvae were identified and checked up after larvicide application. Physical and chemical characteristics of the water in different breeding sites were determined as well. Comparative studies were done among the above mentioned larvicide, and presistence and cost effectiveness of these compounds were determined. I- Laboratory Studies Third and early fourth instar larvae of the first generation of the laboratory reared Cx. pipiens complex collected during the peak densities in the study area (Agricultural and animal husbandry farms, Al-Wafra), Kuwait State were used in the laboratory experiments. The susceptibility of these larvae to the selected larvicides, temephos, dimilin, B. t. i. and B. s. was determined. The procedure for susceptibility test was carried out according to the method described by WHO (1981). The obtained results can be summarized as follows: ? Temephos (abate) As regards susceptibility of Cx. pipiens complex to temephos as revealed from the present work 1998/99, the LC50 value was 0.037 ppm. ranging between 0.023 ppm-0.058 ppm with 95 CL and the slope value was 0.98 unit. Previous studies on value of Cx. pipiens complex from the same study area showed LC50 value (0.018 ppm), ranging between 0.013 ppm -0.023 ppm with 95 of CL and the slope value was 0.88 unit during the year 1994. It might be concluded that Cx. pipiens larvae in the State of Kuwait but its response still homogenous to temephos. ? Insect Growth Regulator (dimilin) Concerning susceptibility of Cx. pipiens complex larvae to dimilin as revealed from the present study 1998/99, the LC50 value was 0.23 ppm ranging between 0.133 ppm-0.369 ppm with 95 of CL and the slope value was 0.89 unit (SE 0.107). Morphological aberrations induced by dimilin treatment are shown in (figures, 11a, b, c, and d). In 1994, previous studies on larvae of Cx. pipiens complex collected from the same study area showed that the LC50 value was 0.24 ppm ranging between 0.14 ppm-0.38 ppm with 95 of CL and the slope value was 0.518 unit. The response of Cx. pipiens complex towards dimilin was still homogenous. This may be attributed to that no wide scale applications of IGRs had been adopted in the country. Microbial Agents ? Bacillus thuringiensis israelensis (B. t. i.) During the present study 1998/99, the susceptibility test of Cx. pipiens complex to B. t. i. indicated that LC50 value was 0.009 ppm ranging between 0.008 ppm-0.010 ppm with 95 of CL, 24 hr, and the slope value was 3.44 unit. Showing the homogenicity of Cx. pipiens complex towards the B. t. i. ? Bacillus sphaericus (B. s.) LC50 of the reference strain SPH-88 B. spharericus strain 2362 to Cx. pipiens complex larvae in the state of Kuwait (48 hr. exposure period) as revealed from the present study was 0.0198 mg/l ranging between 0.017 ppm-0.227 ppm with 95 of CL and the slope value was 3.094 unit. Showing the homogenicity of Cx. pipiens complex larvae towards B. spharericus as indicated from the well filted regression line. The gross morphogenetic aberration features on the 3rd-4th instar larvae of Cx. pipiens complex detected after the application of both B. t. i. and B. s. are shown in figures (121, and 2). II- Field Studies The present field studies 1998/99 were carried out in agriculture and animal husbandry farms area (Al-Wafra), the State of Kuwait. The larvicidal effect of each of tested compounds was determined, in the mean time, the persistence of temephos, B. t. i. and B. s. at the site of application was studied using 100 larvae placed in isolation cage and exposed for 24 hr at different time intervals, then the mortalities were counted. In case of dimilin the larvae were continously exposed till the adults in the control site were successfully emerged. This procedure was repeated at 1, 14, and 35 days following application. ?