Evaluation of Cold and Thermal Fogging Spraying Methods for Mosquito Control.

The efficacy of three pyrethroid insecticides (lambda-cyhalothrin, deltamethrin, and cyphenothrin) in cold (CF) and thermal fogging (TF) applications against caged adults of Culex pipiens Linnaeus were evaluated under hot-dry conditions in Riyadh, Saudi Arabia. The efficacy of CF and TF at different distances from the release point (15, 30, 45, and 60 m) and height (1 and 2 m) was also investigated by evaluating adult mortality after 24 h of exposure. Our data indicated that TF was more efficacious than CF. While the distance from the spray path did not affect TF efficacy, CF showed decreased efficacy with the increase in distance from the spray path. Deltamethrin efficacy was significantly affected by both the application method and distance from the spray path, whereas lambda-cyhalothrin was only affected by the spray method.

Effect of azadirachtin of neemix-4.5 on SWR/J mice.

Inbred normal SWR/J male and female mice, 8-10 weeks old and weighing 22.55-26.72 g, were used throughout the study. A total of 100 males and 100 females were used and were divided into 20 groups, 10 animals in each group. Azadirachtin of neemix-4.5, a commercial botanical pesticide derived from the neem tree, orally administered to male and female SWR/J mice at a dose level 9.0 mg/kg (1/10 LD50) for different treatment periods (2, 4, 6, 8 or 11.5 weeks) has produced signs of toxicity, mortality and changes in body and tissue weights of both sexes at almost all treated periods used in the present study. Moreover the oral administration of this dose level for 11.5 weeks has also resulted in some histopathological changes in the livers, kidneys and testes of treated animals compared with the control group, and the degree of these changes ranged from mild to severe in these organs of treated males. However, conflicting results have been reported concerning the toxicity of azadirachtin in mammalian species using different formulations of neem-based pesticides. It appears, therefore, that the toxicity produced by neemix-4.5 in the present study may be due to factors other than azadirachtin in this formulation.

Efficacy of flumethrin and coumaphos against the camel tick Hyalomma dromedarii L. (Acari: Ixodidae).

The efficacy of Flumethrin pour on and Coumaphos 50% WP was tested against different stages of Hyalomma dromedarii. With contact method, LC50 values for larvae and adults were 0.04, 0.03 ug/cm2 and 0.05, 1.06 ug/cm2 respectively. The LC50 for coumaphos against the larvae, adults and eggs using dipping method were 44, 63, and 62 ppm respectively. Flumethrin caused significant reduction in oviposition and hatchability in female ticks that survived sublethal concentrations, while sublethal doses of coumaphos had no effect on the reproductive potential of the tick. The results showed that flumethrin was 8 times more toxic than coumaphos.

Uscharin, the most potent molluscicidal compound tested against land snails.

Calotropis procera, is a shrub with broad ovate fleshy leaves that grows wild in the Egyptian deserts. The plant was discovered to be highly toxic to the land snailsThepa pisana. The active ingredient responsible for the molluscicidal activity was isolated from its latex by solvent extraction and partitioning and was finally purified by fractional crystallization from 95% aqueous ethanol. The purity of the isolated material was monitored by TLC. Chemical identification was carried out using mass, infrared, and proton magnetic resonance spectroscopic methods. The active compound was found to be uscharin, and its identity was confirmed by comparing its spectroscopic data with the literature values. The isolated compound was 128 times more toxic than methomyl to the snails tested.