Preliminary studies on some effects of bacillus thuringiensis H-14 on culex univittatus larvae in Saudi Arabia

Exposing the second, third and fourth larval instars of culex univittatus to LC[50] of Bacillus thuringiensis H-14, neither delayed pupation nor delayed emergence occurred. Also the sex ratio was increased. It was observed that there was a reduction in the number of eggs laid by the females that developed from surviving larvae. Moreover there was a reduction in the percentage of hatchability of eggs. Also the longevity of female and male emerged adults was decreased

Laboratory studies on chemosterilization of culex univittatus with thiotepa

The results approved that with different exposure periods males and females of Culex univittatus can be sterilized by a range of concentrations of thiotepa. Shamara et al., [1973] found the same result with Culex pipiens fatigans. There was little difference in te survival pattern of the chemosterilized males and the normal mosquitoes. The results showed also that the presence of females reduced the life span of males. It was found that the levels of sterility in males reduced little by the time elapsed after treatment

Effect of some insecticides on certain biochemical enzymes of nervous system in different blood groups

Profenofos, fenitrothion, malathion and methomyl were tested for their interaction with ChE and MAO enzymes in-vitro activity of the blood group samples A, B, AB, and O. ChE was slightly affected. The degree of inhibition of ChE varied according to the type of blood group. On the contrary MAO was activated slightly. B-variation in blood biochemical constituents in different blood groups: The base line for the biochemical constituents content in the different blood group samples was investigated. Variations in the levels of 6 biochemical parameters were obvious between the four blood groups. Generally blood group O got the highest level in TG., B-lipoprotein and total phosphorus. On the other hand, blood group A showed the lowest level in TG. And B-lipoprotein while the same group had the highest level in copper, iron and calcium. These clear variations were found statistically significant. Thus these were differentiations between the blood groups in the specific biochemical constituents. Such specific differences should lead to variations in the response towards the toxication of insecticides and other toxicants

comparative toxicity of some synthetic pyrethroids to white male mice and culex pipens larvae

The selective toxicity of three synthetic parathyroid cypermethrin, decamethrin and fenvalerate, against male mice and mosquito larvae was studied for their use household application. Also, the suggested inhibitory effect of these compounds against ATPase and aniline hydroxylase activities in both species was studied

Susceptibility of anopheles pharoensis to synthetic pyrethroids compared with an insect growth regulation

Three synthetic pyrethroids and an insect growth regulator [IGR] were evaluated against larvae and pupae of An.pharoensis. Of all compounds tested the decamethrin was the most effective. An.pharoensis were more susceptible at LC[90] level to the synthetic pyrethroids than to IGR Altosid SR-10. LC[90] values for decamethrin, permethrin, fenvalerate and Altosid against larvae were 0.03 - 2.40 - 7.90 and 9.4 ppb respectively. LC[90] values for these compounds against pupae were 0.4 - 4.8 - 12.8 and 13.3 ppb respectively