Frequency and spatial distribution of knock‐down resistance (kdr) to pyrethroids in multiple oilseed rape pest species of the genus Ceutorhynchus

Abstract

BackgroundThe protection of European oilseed rape (OSR) from damaging insects relies on pyrethroid insecticides, but the development of resistance in key coleopteran pests such as the pollen beetle (Brassicogethes aeneus) and the cabbage stem flea beetle (Psylliodes chrysocephala) has resulted in reduced effectiveness of these insecticides. The sodium channel gene mutation L1014F knock‐down resistance (kdr) is a contributing factor in resistance to pyrethroids in B. aeneus and P. chrysocephala, but little is known about the status of resistance in weevils of the genus Ceutorhynchus (Coleoptera: Curculonidae). Therefore, the present study investigated pyrethroid susceptibility and the presence of the kdr mutation in four Ceutorhynchus species.ResultsThe kdr mutation in either its heterozygous or homozygous form was found in all investigated Ceutorhynchus species (C. picitarsis, C. pallidactylus, C. napi and C. obstrictus). Samples where pyrethroids in bioassays still provided control at 100% field rate or below contained kdr at frequencies of ≤12.5%, whilst bioassays using 100% field rate that did not control Ceutorhynchus populations contained homozygous resistant individuals at frequencies of greater than 55%. Field sampling demonstrated that kdr frequencies in populations of C. picitarsis and C. obstrictus collected from across France and Germany ranged from 0 to 100%.ConclusionThe present study demonstrated the potential of all four Ceutorhynchus species tested to develop pyrethroid resistance via the L1014F (kdr) mutation. Although kdr frequency varies among species and geographic locations, the risk of loss of pyrethroid insecticide effectiveness is high. Integration of other control tools for resistance management is therefore needed. © 2023 Society of Chemical Industry.

Genetic characterization of 2 Ceutorhynchus (Coleoptera: Curculionidae) weevils with mitogenomes and insights into the phylogeny and evolution of related weevils

“…Current research is primarily focused on genetic comparisons of the 3 species, with limited attention given to descriptions and comparisons of their morphological characteristics. Future studies should further analyze and compare these aspects for verification purposes ( Šedivý and Kocourek 1994 , Milovac et al 2017 , Daum et al 2023 ).…”

“…In addition, the biology of Ceutorhynchus and allied genera remains poorly understood despite previous studies indicating their preference for cruciferous plants and other potential hosts ( Gillett et al 2014 , D’Ottavio et al 2023 , Daum et al 2023 , Katovich et al 2023 ). This brings a huge challenge for the taxonomic classification of these species, as there are only a limited number of defining characteristics for many closely related species, especially of the large genus Ceutorhynchus .…”

Integrated pest control in oilseed crops—new advances from the rapeseed research community

“…1 New research to meet these challenges has been stimulated and has provided more evidence that insecticide resistance in insect pests of OSR is prevalent across Europe, as well as information on the mechanisms and mutations responsible. 6,7 Application of insecticides only when necessary, i.e. when pest populations have breached a certain threshold, will help to reduce selection pressure for insecticide resistance.…”

“…The development of resistance to insecticides in insect pests and the EU banning of several effective and widely used insecticidal compounds, not least the neonicotinoids, has made insect pest management in OSR a serious challenge to farmers 1 . New research to meet these challenges has been stimulated and has provided more evidence that insecticide resistance in insect pests of OSR is prevalent across Europe, as well as information on the mechanisms and mutations responsible 6,7 . Application of insecticides only when necessary, i.e.…”