title: Identification of the Temperature Induced Larvicidal Efficacy of Agave angustifolia against Aedes, Culex, and Anopheles Larvae.
abstract: Synthetic insecticides are generally employed to control the mosquito population. However, their injudicious over usage and non-biodegradability are associated with many adverse effects on the environment and mosquitoes. The application of environment-friendly mosquitocidals might be an alternate to overcome these issues. In this study, we found that organic or aqueous extracts of Agave angustifolia leaves exhibited a strong larvicidal activity (LD50 28.27 μg/ml) against Aedes aegypti, Culex quinquefasciatus, and Anopheles stephensi larvae within a short exposure of 12 h. The larvicidal activity of A. angustifolia is inherited and independent of the plants vegetative growth. Interestingly, the plant larvicidal activity was observed exclusively during the summer season (April-August, when outside temperature is between 30 and 50°C) and it was significantly reduced during winter season (December-February, when the outside temperature falls to ~4°C or lower). Thus, we hypothesized that the larvicidal components of A. angustifolia might be induced by the manipulation of environmental temperature and should be resistant to the hot conditions. We found that the larvicidal activity of A. angustifolia was induced when plants were maintained at 37°C in a semi-natural environment against the controls that were growing outside in cold weather. Pre-incubation of A. angustifolia extract at 100°C for 1 h killed 60% larvae in 12 h, which gradually increased to 100% mortality after 24 h. In addition, the dry powder formulation of A. angustifolia, also displayed a strong larvicidal activity after a long shelf life. Together, these findings revealed that A. angustifolia is an excellent source of temperature induced bioactive metabolites that may assist the preparedness for vector control programs competently.
authors.affiliation: Vector Biology Laboratory, Department of Biological Sciences, Birla Institute of Technology and Science , Pilani , India.
authors.forename: Mithilesh
authors.initials: M
authors.lastname: Kajla
authors.affiliation: Vector Biology Laboratory, Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, India; Graduate School of Biological Sciences, University of Cologne, Cologne, Germany.
authors.forename: Kurchi
authors.initials: K
authors.lastname: Bhattacharya
authors.affiliation: Vector Biology Laboratory, Department of Biological Sciences, Birla Institute of Technology and Science , Pilani , India.
authors.forename: Kuldeep
authors.initials: K
authors.lastname: Gupta
authors.affiliation: Vector Biology Laboratory, Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, India; Institute of Genetics and Molecular and Cellular Biology, Illkirch, France.
authors.forename: Ujjwal
authors.initials: U
authors.lastname: Banerjee
authors.affiliation: Vector Biology Laboratory, Department of Biological Sciences, Birla Institute of Technology and Science , Pilani , India.
authors.forename: Parik
authors.initials: P
authors.lastname: Kakani
authors.affiliation: Vector Biology Laboratory, Department of Biological Sciences, Birla Institute of Technology and Science , Pilani , India.
authors.forename: Lalita
authors.initials: L
authors.lastname: Gupta
authors.affiliation: Vector Biology Laboratory, Department of Biological Sciences, Birla Institute of Technology and Science , Pilani , India.
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Kumar
keywords: Agave angustifolia; larvicidal activity; mosquito; plant extract; vector-borne diseases