Cross‐resistance to three phenylpyrazole insecticides and A2′N mutation detection of GABA receptor subunit in fipronil‐resistant Laodelphax striatellus (Hemiptera: Delphacidae)

Abstract

This study could help us better understand the cross-resistance mechanisms in L. striatellus, and be beneficial for proposing effective pest management strategies of phenylpyrazole resistance. © 2016 Society of Chemical Industry.

Fiprole insecticide resistance of Laodelphax striatellus: electrophysiological and molecular docking characterization of A2′N RDL GABA receptors

“…Surprisingly, resistance to flufiprole (resistance ratio 3.4–8.1 fold) and ethiprole (resistance ratio, 47.1–100.9 fold) have already been detected in field populations of N. lugens , which belongs to the same family of Delphacidae as L. striatellus . During preparation of this manuscript, cross‐resistance among the three fiprole insecticides in fipronil‐resistant L. striatellus was reported as well …”

“…As shown in Table , there is cross‐resistance among the fiprole insecticides in ethiprole‐resistant L. striatellus . While L. striatellus developed high levels of resistance to ethiprole (> 5000 mg L −1 ), and moderate levels to flufiprole (121.29 mg L −1 ), a similar trend became evident in N. lugens during 2014–2015 in China…”

“…Knowledge of the mechanism of cross‐resistance is very important for its control and providing guidelines for insecticide use. Although the mechanism related to fipronil resistance in L. striatellus was been studied in several reports, the cross‐resistance mechanism between fipronil, ethiprole, and flufiprole is still not clear. To date, the resistance mechanisms of L. striatellus to ethiprole were reported and mainly involved detoxification enzymes, such as GSTs, esterase and CYPs, and mutations of GABAR subunit RDL, including A2′S, A2′N and R300Q .…”

“…Phenylpyrazole (fiprole) insecticides, including ethiprole and flufiprole (also referred to as butene‐fipronil) (Fig. ), are still widely used in China to control rice planthoppers (e.g.…”

“…small brown planthopper, Laodelphax striatellus (Fallén); white‐backed planthopper, Sogatella furcifera (Horváth); and brown planthopper, Nilaparvata lugens (Stål)), which are important insect pests that cause severe damage by transmitting plant viral diseases, such as rice stripe virus, rice black streaked‐dwarf virus and maize rough dwarf virus, even though the fipronil has been partly banned in rice. The fiprole insecticides with the same skeleton structures but different substituent moieties act at the GABACls as non‐competitive antagonists . Although the fipronil binding site in invertebrates, such as A2′S in Drosophila , N. lugens and Oulema oryzae , has been extensively studied, the action of ethiprole and flufiprole in insects, especially at the electrophysiological level, was only recently reported .…”