The photosensitizing activity of different photosensitizers irradiated with sunlight against aquatic larvae of Culex pipiens L. (Diptera: Culicidae)

A. El-Mehdawy Et Al., Ahmed

doi:10.21608/ejabf.2021.205672

The photosensitizing activity of different photosensitizers irradiated with sunlight against aquatic larvae of Culex pipiens L. (Diptera: Culicidae)

Document Type : Original Article

Author

Ahmed A. El-Mehdawy et al.

10.21608/ejabf.2021.205672

Abstract

The response of Culex pipiens early 3^rd instar larvae to three photosensitizing dyes (Toluidine blue O, Methylene blue, and Rose Bengal) was studied under laboratory conditions. Despite lack of toxicity in dark and with exposure to only sunlight, C. pipiens third instar larvae were highly sensitive to the three tested photosensitisers with 20 minutes of sunlight irradiation. Larvae showed the most sensitivity to Rose Bengal (RB) with LC₅₀ values of 1.07, 1.19, 1.35, 1.65µM, and LC₉₀ values of 3.88, 3.98, 4.19, and 4.51µM. Also, less sensitivity to methylene blue (MB) was recorded with LC₅₀ values of 2.70, 2.79, 2.99, 3.08µM and LC₉₀ values of 4.82, 4.90, 5.04, and 5.22µM. In addition, the least sensitivity was recorded by larvae towards toluidine blue o (TBO) with LC₅₀ values of 3.30, 3.39, 3.58, and 3.87µM and LC₉₀ values of 5.23, 5.32, 5.57, and 5.96 µM, respectively. Results showed that photosensitizers could be an excellent replacement for the traditional insecticides avoiding their negative impact on the environment.

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