title: Insecticide resistance status and mechanisms in Malaysian Blattella germanica (Linnaeus).
abstract: The insecticide resistance status of 4 strains of adult male Blattella germanica, viz M (Malacca), E (England), F (restaurant) and K (cafeteria) against malathion and bendiocarb compared with a reference susceptible strain (S) was determined by using a modified WHO bioassay method. The results indicated that all the 4 strains were resistant to the insecticides albeit in different degrees. Resistance ratios for malathion ranged from 1.85-41.07-fold, whereas that of bendiocarb ranged from 1.68-4.83-fold. The biochemical microplate enzyme assays technique employed indicated that the resistance in M and E strains were attributed to acetylcholinesterase insensitivity. Multiple resistance was not detected in any of the 4 strains. Parameters of the identified resistance mechanism correlated well with the observed level of resistance. Agar gel electrophoresis showed that variations in esterase isoenzymes did not confer organophosphate and carbamate resistance to the 4 strains.
authors.affiliation: Division of Medical Entomology, Institute for Medical Research, Kuala Lumpur.
authors.forename: H L
authors.initials: HL
authors.lastname: Lee
authors.forename: W D
authors.initials: WD
authors.lastname: Tien
authors.forename: B
authors.initials: B
authors.lastname: Omar
mesh_terms: D000818:Animals; D002219:Carbamates; D003058:Cockroaches; D003906:Developing Countries; D004305:Dose-Response Relationship, Drug; D007305:Insecticide Resistance; D007306:Insecticides; D008294:Malathion; D008296:Malaysia; D008297:Male; D048448:Phenylcarbamates; D013045:Species Specificity
chemical_list: D002219:Carbamates; D007306:Insecticides; D048448:Phenylcarbamates; C007725:bendiocarb; D008294:Malathion