title: Tagetes erecta Linn. and its mosquitocidal potency against Culex quinquefasciatus.
abstract: OBJECTIVE
  To investigate mosquitocidal effects of ethanolic extract of flowers of Tagetes erecta (T. erecta) and its chloroform and petroleum ether soluble fractions against the larvae of Culex quinquefasciatus (Cx. quinquefasciatus).
  
  
  METHODS
  The fresh flowers of T. erecta were extracted in cold with ethanol (5.0 L) and after concentration, the ethanol extract was fractionated with chloroform and petroleum ether to afford a brownish syrupy suspension of ethanol extract (50.0 g), petroleum ether soluble fraction (18.6 g) and chloroform soluble fraction (23.8 g). The larvicidal effect of ethanol extract and their solvent fractions were determined by the standard procedure of WHO against different instars of Cx. quinquefasciatus.
  
  
  RESULTS
  Among the tested samples the chloroform soluble fractions showed the highest toxicity and consequently, the lowest LC50 values (14.14 µg/mL, 17.06 µg/mL, 36.88 µg/mL and 75.48 µg/mL) for all the instars larvae of Cx. quinquefasciatus. The larvae showed comparative tolerance in the course of increasing age and time.
  
  
  CONCLUSIONS
  It can be concluded that the flowers of T. erecta are very effective natural larvicide and could be useful against Cx. quinquefasciatus.
authors.affiliation: Department of Biochemistry and Molecular Biology, Rajshahi University, Rajshahi-6205, Bangladesh.
authors.forename: Farjana
authors.initials: F
authors.lastname: Nikkon
authors.forename: M Rowshanul
authors.initials: MR
authors.lastname: Habib
authors.forename: Zahangir Alam
authors.initials: ZA
authors.lastname: Saud
authors.forename: M Rezaul
authors.initials: MR
authors.lastname: Karim
mesh_terms: D000818:Animals; D003465:Culex / Q000187:drug effects*; D035264:Flowers / Q000737:chemistry; D007306:Insecticides / Q000494:pharmacology*; D007928:Lethal Dose 50; D021261:Parasitic Sensitivity Tests; D010936:Plant Extracts / Q000494:pharmacology*; D031686:Tagetes / Q000737:chemistry*
chemical_list: D007306:Insecticides; D010936:Plant Extracts
keywords: Culex quinquefasciatus Say; Larvae; Larvicidal effect; Mosquitocidal; Tagetes erecta Linn.; Toxicity