title: Efficacy of various larvicides against Aedes aegypti immatures in the laboratory.
abstract: We conducted a laboratory study to evaluate the efficacy of control agents against small larvae, large larvae, and pupae of Aedes aegypti to determine an appropriate larvicide regime to employ in emergency dengue control programs. The control agents included Bacillus thuringiensis var. israelensis (Bti), pyriproxyfen (an insect growth regulator), a larvicidal oil, Aquatain AMF (polydimethylsiloxane, a monomolecular film), and temephos at the recommend application dosages and rates. Our results showed that Bti, pyriproxyfen, and temephos were efficacious (100% mortality) against larvae, irrespective of the instar stage, but not against pupae of Ae. aegypti (1.5-7.8% mortality). Aquatain AMF, on the other hand, was very effective at controlling the pupal stage (100% mortality), but had limited efficacy against small larvae (38.0% mortality) and large larvae (78.0% mortality). The larvicidal oil was effective against all immature stages (93.3-100% mortality). Therefore, we concluded that for effectively interrupting the dengue transmission cycle, larvicides that kill the pupal stage (Aquatain AMF or larvicidal oil) should be included in an emergency dengue control program in addition to Bti, pyriproxyfen, or temephos.
authors.affiliation: Research and Diagnostic Center, Centers for Disease Control, Taipei, Taiwan.
authors.forename: Chih-Yuan
authors.initials: CY
authors.lastname: Wang
authors.forename: Hwa-Jen
authors.initials: HJ
authors.lastname: Teng
authors.forename: Si-Jia
authors.initials: SJ
authors.lastname: Lee
authors.forename: Cheo
authors.initials: C
authors.lastname: Lin
authors.forename: Jhy-Wen
authors.initials: JW
authors.lastname: Wu
authors.forename: Ho-Sheng
authors.initials: HS
authors.lastname: Wu
mesh_terms: D000330:Aedes / Q000187:drug effects*; D000818:Animals; D001681:Biological Assay; D003715:Dengue / Q000517:prevention & control; D005260:Female; D006801:Humans; D007306:Insecticides / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects; D009032:Mosquito Control / Q000379:methods; D011679:Pupa / Q000187:drug effects; D016019:Survival Analysis
chemical_list: D007306:Insecticides