biological effects of the insect growth regulators; pyriproxyfen and diflubenzuron on the mosquito Aedes aegypti

The biological effects of two insect growth regulators [IGRs], pyriproxyfen and diflubenzuron against larvae of the mosquito Aedes aegypti [L.] have been evaluated. Mosquitoes were collected from Jeddah governorate, west of the Kingdom of Saudi Arabia and maintained in the laboratory. According to IC[50] values obtained [concentrations which inhibit the emergence of 50% of adults], diflubenzuron [0.00036 ppm] proved to be more effective by 11.4 fold of pyriproxyfen [0.0041ppm]. In addition to the delayed lethal action, larval treatment with the two IGRs, pyriproxyfen and diflubenzuron led to pronounced reduction in the reproductive potential of mosquito adults that emerged from these treatments. Pyriproxyfen caused a 33.2% decrease in egg production compared to 25.5% for diflubenzuron. The reduction in egg hatchability was by 40.6 and 36.2 % for pyriproxyfen and diflubenzuron, respectively, with up to 4 fold higher reduction rates than in the control tests. These results shed light on the extended biological effects of IGRs on mosquitoes and encourage further testing of IGRs for wider use in the control of Ae. aegypti and other important disease vectors in Arabia and the world

Human zoonotic cutaneous leishmaniasis and associated sand flies [Diptera: psychodidae] in Sheikh Atiya village, southern Sinai, Egypt

During entomological surveys conducted in Southern Sinai in the summers of 1997-1999, a clinically confirmed zoonotic cutaneous leishmaniasis [ZCL] case was encountered for the first time in Sheikh Atiya Village in June 1999. The parasite was isolated and identified as L. major using cellulose acetate electrophoresis. A total of 784 phlebotomine sand flies was collected. Sand fly species composition at Sheikh Atiya Village showed that P. papatasi and P. alexandri were the most abundant species in the area and each comprises about 47% of the collected files. P. sergenti and P. kazeruni occurred in very low numbers. All the female flies dissected [N = 304] were negative for any Leishmania-like flagellates. When the identified isolate was inoculated in the footpads of a clean laboratory colonized Acomys cahirinus dimidiatus, a lesion was developed on the site of inoculation nine months post-injection