Risk assessment and resistance inheritance of triflumezopyrim resistance in Laodelphax striatellus

Abstract

BACKGROUND: Laodelphax striatellus (Fallén) (Hemiptera: Delphacidae) is one of the most important insect pests of rice, and it has been able to develop strong resistance to many insecticides. Triflumezopyrim, a new type of mesoionic insecticide developed by Corteva Agriscience, showed high biological activity in controlling piercing-sucking insect pests such as planthopper and leafhopper.RESULTS: In this study, we continuously selected a susceptible laboratory stain (Unsel) of L. striatellus for 16 generations by exposing it to triflumezopyrim in the laboratory. A 45.1-fold triflumezopyrim-resistant strain (Tri-sel) was established, in which cross-resistance to nitenpyram and acetamiprid was not detected. The realized heritability (h 2 ) of the Tri-sel strain was estimated at 0.13. The mortalities of the testing F 1 (the offspring of a cross between Unsel and Tri-sel strains) suggested that the resistance of L. striatellus to triflumezopyrim was autosomal and incompletely dominant, as well as a polygenic inheritance. In addition, the results of synergist experiment showed that P450s potentially contributed to the triflumezopyrim resistance. The activities of detoxification enzymes in the Unsel and Tri-sel strains indicated that the activity of P450s in the Tri-sel strain was significantly increased, consistent with the results of synergist experiments. Furthermore, 12 P450 genes demonstrated significant up-regulation. CONCLUSIONS: L. striatellus has a certain risk of resistance to triflumezopyrim after continuous selection. Triflumezopyrim resistance did not result in cross-resistance to neonicotinoid insecticides. The up-regulation of multiple P450 genes may mediate triflumezopyrim resistance in L. striatellus.

Resistance selection of triflumezopyrim in Laodelphax striatellus (fallén): Resistance risk, cross-resistance and metabolic mechanism

“…But the resistance was rapidly increased to 26.29-fold after the F 8 generation, reaching the middle resistance level. However, previous study showed SPBH could increase 45.1-fold to TFM only after 16 generations selection ( Zhang et al, 2022 ). This different result may be due to the differences of selection method.…”

“…Frontiers in Physiology frontiersin.org to TFM only after 16 generations selection (Zhang et al, 2022). This different result may be due to the differences of selection method.…”

“…C et al (2020) estimated that during the development of TFM resistance in N. lugens , h 2 was 0.0451. Recent studies have reported that the h 2 of TFM resistance in SBPH was 0.13 ( Zhang et al, 2022 ). When the TFM selection pressure was used with a survival rate of 50% in each generation, the LC 50 values could increase 10-fold only in 6.72 generations.…”

“…These genes encode the P450 enzymes, which can metabolize imidacloprid and mediate the generation of resistance to imidacloprid (Elzaki et al, 2016;Elzaki et al, 2017;Wang et al, 2017;Xiao et al, 2019). Zhang et al (2022) found that seven P450 genes were up-regulated more than 1.5fold in TFM-resistance strain of SBPH, but only three genes were up-regulated more than 2-fold. In our study, compared with SS strain, nine genes were more than 2-fold overexpressed in the RS strain, which CYP303A1, CYP4CE2, and CYP419A1v2 were significantly up-regulated.…”

“…Previous researches reported that sublethal doses of TFM could significantly affect population development and detoxification enzyme activities of Sogatella furcifera (Horvath) ( Chen et al, 2020 ) and SBPH ( Wen et al, 2021b ). The new study reported that SBPH had a certain risk of resistance to TFM after a short-term continuous selection ( Zhang et al, 2022 ).…”