Essential Oil Compositions of Three Invasive Conyza Species Collected in Vietnam and Their Larvicidal Activities against Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus.

Tran Minh Hoi,Hoang Van Chinh,Nguyen Huy Hung,Thieu Anh Tai,William N Setzer,Prabodh Satyal,Do Ngoc Dai,Le Thi Huong,Vu Thi Hien,Dang Viet Hau

doi:10.3390/molecules25194576

Abstract

Mosquito-borne infectious diseases are a persistent problem in tropical regions of the world, including Southeast Asia. Vector control has relied principally on synthetic insecticides, but these have detrimental environmental effects and there is an increasing demand for plant-based agents to control insect pests. Invasive weedy plant species may be able to serve as readily available sources of essential oils, some of which may be useful as larvicidal agents for control of mosquito populations. We hypothesize that members of the genus Conyza (Asteraceae) may produce essential oils that may have mosquito larvicidal properties. The essential oils from the aerial parts of Conyza bonariensis, C. canadensis, and C. sumatrensis were obtained by hydrodistillation, analyzed by gas chromatography–mass spectrometry, and screened for mosquito larvicidal activity against Aedes aegypti, Ae. albopictus and Culex quinquefasciatus. The essential oils of C. canadensis and C. sumatrensis, both rich in limonene (41.5% and 25.5%, respectively), showed notable larvicidal activities against Ae. aegypti (24-h LC50 = 9.80 and 21.7 μg/mL, respectively) and Ae. albopictus (24-h LC50 = 18.0 and 19.1 μg/mL, respectively). These two Conyza species may, therefore, serve as sources for alternative, environmentally-benign larvicidal control agents.

Highlights

Mosquito-borne infectious diseases have been a continuous health problem in Southeast Asia, including Vietnam
We have recently studied several introduced invasive plant species in Vietnam for potential use as mosquito vector control agents [33,34,35], and as part of our ongoing efforts in identifying readily-available essential oils for mosquito control, we have examined three Conyza species for larvicidal activity against Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus, with the aim of identifying new mosquito-control essential oils and the components responsible for the activity
The essential oils from the aerial parts of C. bonariensis, C. canadensis, and C. sumatrensis were obtained by hydrodistillation in 1.10%, 1.37%, and 1.21% yield

Summary

Introduction

Mosquito-borne infectious diseases have been a continuous health problem in Southeast Asia, including Vietnam. Aedes aegypti (L.) (Diptera: Culicidae), the yellow fever mosquito, is a recognized vector of dengue fever virus, chikungunya fever virus, Zika virus, and yellow fever virus [3]. Aedes albopictus (Skuse) (Diptera: Culicidae), the Asian tiger mosquito, is a key vector of several pathogenic viruses, including yellow fever virus [4], dengue fever virus [5], chikungunya virus [6], and possibly Zika virus [7]. Culex quinquefasciatus Say (Diptera: Culicidae), the southern house mosquito, is a vector of lymphatic filariasis [8] as well as several arboviruses such as West Nile virus and St. Louis encephalitis virus [9] and possibly Zika virus [10]

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Results

Conclusion