Pesticidal Activities of Callicarpa and Premna Essential Oils From Vietnam

Mosquito-borne diseases are a consistent problem in Vietnam. Additionally, freshwater snail species are agricultural pests and are known to be intermediate hosts for several parasitic worms. There is a need for new and complementary botanical pesticidal agents for controlling these pests and essential oils have shown promise. In this work, essential oils from 2 species of Callicarpa (C. rubella and C. sinuata) and 4 species of Premna (P. chevalieri, P. corymbosa, P. maclurei, and P. tomentosa) were screened for mosquito larvicidal activity against Aedes albopictus and Culex quinquefasciatus and for molluscicidal activity against 3 freshwater snail species, Gyraulus convexiusculus, Pomacea canaliculata, and Tarebia granifera. Callicarpa rubella essential oil showed exceptional larvicidal activity against Cx. quinquefasciatus with 24-h LC50 of 9.8 μg/mL. In addition to C. rubella, the essential oils of P. chevalieri and P. tomentosa showed notable molluscicidal activities against P. canaliculata with LC90 values ≤ 20 μg/mL. These Callicarpa and Premna essential oils were all rich in sesquiterpenes and should be considered for continued investigation as botanical pesticidal agents.