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Abstract The goal of this work is to test the potency of the photosensitizers hematoporphyrin (HP) and methylene blue (MB) as photopesticides by its application alone or mixing it with adjuvants and with minimum amounts of chemical insecticides to diminish the environmental risk. The effect of HP and MB as photopesticides has been tested according to the survival percentage of the whitefly in two successive seasons for two weeks after their application. We can summarize our results as follow : By application of the sensitizer alone without additives, it was found that the most effective concentration of HP was 1x10-4 M/L. For MB, the most effective concentration was 3x10-3 M/L We found that applying a mixture of the photosensitizer (either HP or MB) with adjuvants such as Triton X-100 (TX-100) and sodium dodecyl sulphate (SDS) markedly enhanced the activity of the used sensitizers against the whitefly, especially the mixture of TX-100 with either HP or MB Combined application of either HP or MB with a little amount of the insecticides such as Malathion and Dimethoate significantly reduced the survival percentage of the whitefly, particularly the mixture of Dimethoate with either HP or MB Generally the photoinsecticidal activity of both HP and MB appear to be increase with increasing their concentration. Radiosterilization is also used to control the whiteflies through the sterility technique by Laser irradiation. Two types of laser were used, argon ion (514.5 nm) and He-Cd (325 nm) lasers. He-Cd laser was more effective in inducing sterility than the argon ion laser. Thus, the laser can be successfully used in sterile insect technique. The effect of the used photosensitizers on the whitefly predator (ants) and host plant chlorophylls content was also investigated in this work. |