TY - JOUR
T1 - Pyrethroid resistance in the pest mite, Halotydeus destructor
T2 - dominance patterns and a new method for resistance screening
AU - Cheng, Xuan
AU - Umina, Paul A.
AU - Lee, Siu Fai
AU - Hoffmann, Ary A.
PY - 2019/9
Y1 - 2019/9
N2 - An L1024F substitution in the para gene, which encodes a subunit of the voltage-gated sodium channel, has been implicated in pyrethroid resistance in a mite pest, Halotydeus destructor, which attacks rape and other grain crops. A high-resolution melt (HRM) genotyping assay was developed for testing the relative pyrethroid susceptibility of different para genotypes and for high-throughput field screening of resistant alleles. The L1024F mutation was found to be incompletely recessive in phenotypic laboratory bioassays with the pyrethroid pesticide, bifenthrin. While the resistance ratio of heterozygotes (RS) to susceptible homozygotes (SS) was <6 in 24 h bioassays, the resistant homozygotes (RR) (with a resistance ratio > 200,000) survived the recommended field rate of bifenthrin (100 mgL−1). HRM genotyping of mites from field populations across Australia indicated the presence of resistant alleles in Western Australia and South Australia, but not in Victoria and New South Wales. The assay developed will be useful for routine screening of pyrethroid resistance, and the dominance relationships established here point to useful resistance management strategies involving the maintenance of reservoirs of susceptible mites to dilute resistant homozygotes in a population.
AB - An L1024F substitution in the para gene, which encodes a subunit of the voltage-gated sodium channel, has been implicated in pyrethroid resistance in a mite pest, Halotydeus destructor, which attacks rape and other grain crops. A high-resolution melt (HRM) genotyping assay was developed for testing the relative pyrethroid susceptibility of different para genotypes and for high-throughput field screening of resistant alleles. The L1024F mutation was found to be incompletely recessive in phenotypic laboratory bioassays with the pyrethroid pesticide, bifenthrin. While the resistance ratio of heterozygotes (RS) to susceptible homozygotes (SS) was <6 in 24 h bioassays, the resistant homozygotes (RR) (with a resistance ratio > 200,000) survived the recommended field rate of bifenthrin (100 mgL−1). HRM genotyping of mites from field populations across Australia indicated the presence of resistant alleles in Western Australia and South Australia, but not in Victoria and New South Wales. The assay developed will be useful for routine screening of pyrethroid resistance, and the dominance relationships established here point to useful resistance management strategies involving the maintenance of reservoirs of susceptible mites to dilute resistant homozygotes in a population.
KW - Incompletely recessive
KW - kdr
KW - Mass screening, genotyping
KW - Pyrethroid resistance
UR - http://www.scopus.com/inward/record.url?scp=85070093072&partnerID=8YFLogxK
U2 - 10.1016/j.pestbp.2019.04.010
DO - 10.1016/j.pestbp.2019.04.010
M3 - Article
C2 - 31400789
AN - SCOPUS:85070093072
VL - 159
SP - 9
EP - 16
JO - Pesticide Biochemistry and Physiology
JF - Pesticide Biochemistry and Physiology
SN - 0048-3575
ER -