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Insecticide resistance, associated mechanisms and fitness aspects in two B razilian S tegomyia aegypti (= A edes aegypti ) populations
Author(s) -
VIANAMEDEIROS P. F.,
BELLINATO D. F.,
MARTINS A. J.,
VALLE D.
Publication year - 2017
Publication title -
medical and veterinary entomology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 82
eISSN - 1365-2915
pISSN - 0269-283X
DOI - 10.1111/mve.12241
Subject(s) - biology , aedes aegypti , pyrethroid , deltamethrin , organophosphate , malathion , toxicology , aedes , larva , pesticide , ecology
In B razil, insecticide resistance in S tegomyia aegypti (= A edes aegypti ) ( D iptera: C ulicidae) populations to pyrethroids and to the organophosphate ( OP ) temephos is disseminated. Currently, insect growth regulators ( IGRs ) and the OP malathion are employed against larvae and adults, respectively. Bioassays with mosquitoes from two northeast municipalities, C rato and A racaju, revealed, in both populations, susceptibility to IGRs and malathion ( RR 95 ≤ 2.0), confirming the effectiveness of these compounds. By contrast, temephos and deltamethrin (pyrethroid) resistance levels were high ( RR 95 > 10), which is consistent with the use of intense chemical control. In Crato, RR 95 values were > 50 for both compounds. Knock‐down‐resistant ( kdr ) mutants in the voltage‐gated sodium channel, the pyrethroid target site, were found in 43 and 32%, respectively, of A racaju and C rato mosquitoes. Biochemical assays revealed higher metabolic resistance activity (esterases, mixed function oxidases and glutathione‐ S ‐transferases) at A racaju. With respect to fitness aspects, mating effectiveness was equivalently impaired in both populations, but A racaju mosquitoes showed more damaging effects in terms of longer larval development, decreased bloodmeal acceptance, reduced engorgement and lower numbers of eggs laid per female. Compared with mosquitoes in C rato, A racaju mosquitoes exhibited lower OP and pyrethroid RR 95 , increased activity of detoxifying enzymes and greater effect on fitness. The potential relationship between insecticide resistance mechanisms and mosquito viability is discussed.