Laboratory evaluation of the effect of Egyptian native plants against some parasitic vectors.

Objective: Four plant extracts possessing molluscicidal and insecticidal efficacy were evaluated under laboratory conditions versus Biomphalaria alexandrina, Lymnea cailliaudi snails, their egg masses and Culex pipiens larvae. These extracts included Grape seed, Eucalyptus, Pomegranate, Verbesina alcoholic extracts, as well as Eucalyptus oil.

Methods: Different mortalities in the exposed vectors were recorded due to the four plant extracts using different concentrations and exposure time.

Results: Total snail mortality LC < sub > 100 < /sub > was (100 ppm/12-24h) for Grape seed, (200 ppm/18-24h) for Eucalyptus, (100 ppm/12-18h) for Pomegranate, (100-200 ppm/24h) for Verbesina alcoholic extracts and (100-200 ppm/12h) for Eucalyptus oil. However, only Eucalyptus, Verbesina alcoholic extracts and Eucalyptus oil revealed snail ovicidal effects. LC < sub > 100 < /sub > was (100-200 ppm/24h), (100-200 ppm/24h) & (100-200 ppm/12-48h) respectively. Moreover, the same plant extracts were able to induce total Culex pipiens larvicidal mortality, LC < sub > 100 < /sub > was (200 ppm/48h). However, Grape seed and Pomegranate alcoholic extracts did not induce either snail ovicidal or Culex pipiens larvicidal total mortalities. Activities of the studied plant extracts were considered using reference molluscicidal (Copper sulfate) and insecticidal (Temephos) substances.

Conclusion: Egyptian native plants continue to provide a wealth of potential sources for biologically active agents that may have a promising role in the production of safe, biodegradable eco-friendly and natural molluscicidal and insecticidal agents.