title: Mosquito larvicidal potential of four common medicinal plants of India.
abstract: OBJECTIVE
  Mosquitoes transmit serious human health diseases, causing millions of deaths every year. Plants may be sources of alternative mosquito control agents. The present study was carried out to assess the role of larvicidal activities of the crude extracts of four plants viz. Alternanthera sessilis L. (Amaranthaceae), Trema orientalis L. (Cannabaceae), Gardenia carinata Smith. (Rubiaceae) and Ruellia tuberosa L. (Acanthaceae) against Culex quinquefasciatus Say in laboratory bioassay.
  
  
  METHODS
  Selective concentrations (0.5, 1 and 1.5%) of crude extract of all four plant leaves were tested against I st to IV th instar larvae of Cx. quinquefasciatus. Log probit analysis (at 95% confidence level) revealed the LC50 values. Preliminary qualitative phytochemical analyses of crude extracts were also done. The lethal concentrations (%) of crude extracts at 24 h against III rd instar larvae were also studied on non-target organisms.
  
  
  RESULTS
  In a 72 h bioassay experiment with crude extract, the highest mortality was recorded in 1.5 per cent extract. A. sessilis showed the highest mortality (76.7%) at 1.5 per cent crude extract against II nd instar larvae having LC50 value of 0.35 per cent, followed by R. tuberosa (LC50 = 1.84%), G. carinata (LC50 = 2.11) and T. orientalis (LC50 = 2.95%). The regression equation showed a dose-dependent mortality, as the rate of mortality (Y) was positively correlated with the concentration (X). Phytochemical analysis of the crude extract showed the presence of many bioactive phytochemicals such as steroids, alkaloids, terpenes, saponins, etc. No changes in the swimming behaviour and survivality of non-target organism were noticed at the studied concentrations.
  
  
  CONCLUSIONS
  Crude extract of the four selected plants showed larvicidal activity against Cx. quinquefasciatus. The extracts at the studied concentrations did not produce any harmful effect on non-target organisms.
authors.forename: Anjali
authors.initials: A
authors.lastname: Rawani
authors.forename: Anupam
authors.initials: A
authors.lastname: Ghosh
authors.affiliation: Department of Zoology, The University of Burdwan, Burdwan, India.
authors.forename: Goutam
authors.initials: G
authors.lastname: Chandra
mesh_terms: D027901:Acanthaceae / Q000737:chemistry*; D027703:Amaranthaceae / Q000737:chemistry*; D000818:Animals; D009033:Culicidae / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D032062:Gardenia / Q000737:chemistry*; D007194:India; D007306:Insecticides / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects; D007928:Lethal Dose 50; D009032:Mosquito Control / Q000379:methods*; D010936:Plant Extracts / Q000032:analysis / Q000494:pharmacology*; D012044:Regression Analysis; D034402:Trema / Q000737:chemistry*
chemical_list: D007306:Insecticides; D010936:Plant Extracts