Search

BACKGROUND Pyrethroid resistance in the common bed bug, Cimex lectularius L., has been reported worldwide. An important resistance mechanism is via knockdown resistance ( kdr) mutations, notably V419L and L925I. Information regarding this kdr-type resistance mechanism is unknown in Australia. This study aims to examine the status of kdr mutations in Australian C. lectularius strains. RESULTS Several modern field-collected strains and museum-preserved reference collections of Australian C. lectularius were examined. Of the field strains (2007-2013), 96% had the known kdr mutations ( L925I or both V419L/ L925I). The 'Adelaide' strain (2013) and samples from the preserved reference collections (1994-2002) revealed no known kdr mutations. A novel mutation I936F was apparent in the insecticide-resistant 'Adelaide' strain, one strain from Perth (with L925I) and the majority of the reference collection specimens. The laboratory insecticide-resistant 'Sydney' strain showed a mixture of no kdr mutations (20%) and L925I (80%). CONCLUSION The novel mutation I936F may be a kdr mutation but appeared to contribute less resistance to the pyrethroids than the V419L and L925I mutations. The detection of high frequencies of kdr mutations indicates that kdr-type resistance is widespread across Australia. Hence, there should be a reduced reliance on pyrethroid insecticides and an integrated management approach for the control of C. lectularius infestations. © 2014 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Insecticide resistance in the common bed bug, C imex lectularius Linnaeus has been suspected in Australia with anecdotal reports of poor product performance. To investigate this possibility, LD50 values were determined via topical application of technical grade permethrin, deltamethrin, bendiocarb, pirimiphos-methyl and imidacloprid serially diluted in acetone to a suspected resistant field-collected strain and a susceptible laboratory strain. All compounds tested against the susceptible strain were efficacious. However, for the field strain, only pirimiphos-methyl and imidacloprid showed high levels of activity. Resistance was confirmed in the field-collected strain to the pyrethroids and bendiocarb, but not to pirimiphos-methyl or imidacloprid. Resistance factors ('resistant' LD50/susceptible LD50) for each compound were: permethrin ≈ 1.235 million, deltamethrin ≈ 370 000, bendiocarb ≈ 250, pirimiphos-methyl = 2.6, imidacloprid = 2.6. Bendiocarb, permethrin and deltamethrin all failed to return greater than 60% mortality at the maximum dose of 100 μg/μ L. This research has significant operational implications for bed bug control and the registration process of new products in Australia. [ABSTRACT FROM AUTHOR]