Chemical Compositions of Crassocephalum crepidioides Essential Oils and Larvicidal Activities Against Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus

Abstract

The leaf, stem, and floral essential oils of Crassocephalum crepidioides growing wild in central Vietnam were obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. The major component in all 3 oils was myrcene (59.3%, 26.1%, and 43.3%, respectively). The 24-hour mosquito larvicidal activities of the oil of the aerial parts (stems and leaves) were determined against wild-caught Aedes albopictus (IC 50 = 14.3 μg/mL), laboratory-reared Aedes aegypti (IC 50 = 4.95 μg/mL), and wild-caught Culex quinquefasciatus (IC 50 = 18.4 μg/mL). The high concentration of myrcene in the essential oil likely accounts for the mosquito larvicidal activity observed.

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

“…Conyza spp., as well as Erechtites spp. [ 34 ], Crassocephalum crepidioides [ 35 ], and Severinia monophylla [ 33 ], are invasive weeds in Vietnam, and essential oils from these plants have demonstrated promising mosquito larvicidal activities. The plant materials are readily available and harvesting of these weeds may provide economically valuable “cash crops” as well as serve as a means for ecological remediation.…”

“…Essential oils have been suggested as viable, environmentally benign, and renewable alternatives to synthetic pesticides [ 28 , 29 , 30 , 31 , 32 ]. 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.…”

Essential Oils of Zingiber Species from Vietnam: Chemical Compositions and Biological Activities

“…albopictus , and Cx. quinquefasciatus were raised in the laboratory as previously described [ 74 ]. Aedes aegypti larvae were reared from eggs (Institute of Biotechnology, Vietnam Academy of Science and Technology).…”

“…Aedes aegypti larvae were reared from eggs (Institute of Biotechnology, Vietnam Academy of Science and Technology). Adults of Culex quinquefasciatus and Aedes albopictus were collected in Hoa Khanh Nam ward, Lien Chieu district, Da Nang city (16°03′14.9″ N, 108°09′31.2″ E) and were maintained as described previously [ 74 ]. Eggs were hatched and the larvae reared as previously described [ 74 ].…”

Chemical Composition of Actinodaphne pilosa Essential Oil From Vietnam, Mosquito Larvicidal Activity, and Antimicrobial Activity

“…Mosquito colonies were obtained and maintained as previously described. 31 Larvicidal activity screening was carried out on 3rd instar larvae of A. aegypti, A. albopictus, and C. quinquefasciatus as previously described. 31 The data obtained were subjected to log-probit analysis to obtain 50% lethal concentration values, 90% lethal concentration values, and 95% confidence limits using Minitab 19 (Minitab, LLC, State College, PA, USA).…”