Baseline susceptibility of Helicoverpa armigera, Plutella xylostella, and Spodoptera frugiperda to the meta‐diamide insecticide broflanilide

Abstract

Broflanilide is a novel meta-diamide insecticide that acts as a γ -aminobutyric acid-gated chloride channel allosteric modulator. With its unique mode of action, broflanilide has no known cross-resistance with existing insecticides and is expected to be an effective tool for the management of insecticide resistance. Establishing the baseline susceptibility to this insecticide is an essential step for developing and implementing effective resistance management strategies. Here we evaluated the baseline susceptibility to broflanilide for 3 cosmopolitan lepidopteran pest species, Helicoverpa armigera, Plutella xylostella, and Spodoptera frugiperda. Broflanilide exhibited high activity against populations sampled in the major distribution range of these pests in China, with median lethal concentrations (LC 50 ) ranging between 0.209 and 0.684, 0.076 and 0.336, and 0.075 and 0.219 mg/L for H. armigera, P. xylostella, and S. frugiperda, respectively. Amongpopulation variability in susceptibility to broflanilide was moderate for H. armigera (3.3fold), P. xylostella (4.4-fold), and S. frugiperda (2.9-fold). The recommended diagnostic concentrations for H. armigera, P. xylostella, and S. frugiperda were 8, 4, and 2 mg/L, respectively. Little or no cross-resistance to broflanilide was detected in 3 diamide-resistant strains of P. xylostella and 1 spinosyns-resistant strain of S. frugiperda. Our results provide critical information for the development of effective resistance management programs to sustain efficacy of broflanilide against these key lepidopteran pests.

Baseline Susceptibility, Cross-Resistance, and Sublethal Effects of Broflanilide, a Novel Meta-Diamide Pesticide, in Spodoptera litura

“…Moreover, we found a narrow range of geographical variation in broflanilide susceptibility between populations (less than five-fold resistance ratio). Another study revealed that field populations of the insect pests P. xylostella , H. armigera , and S. frugiperda in China are highly susceptible to broflanilide [ 5 ]. This novel insecticide could thus be a powerful tool to control the four lepidopteran species of the most common and highly damaging insect pests in China.…”

“…These comparisons indicated a little significant cross-resistance, meaning that it is highly feasible to rotate broflanilide with metaflumizone, chlorantraniliprole, and pyridalyl in the field to combat S. litura . Similarly, significant cross-resistance to broflanilide was not observed in three diamide-resistant populations of diamondback moth and one spinosyns-resistant population of fall armyworm [ 5 ]. Earlier reports indicated that broflanilide displays excellent efficiency against fipronil- and dieldrin-resistant housefly, fipronil-resistant Sogatella furcifera and Oulema oryzae , diamide-resistant diamondback moth [ 1 , 35 ], and dieldrin- and pyrethroid-resistant Anopheles gambiae [ 36 , 37 ].…”

“…The Insecticide Resistance Action Committee has classified it in a novel group (group 30) based on its action as an allosteric modulator of GABAR [ 2 ]. It not only exhibits excellent lethal effects against a host of lepidopteran pests, such as Plutella xylostella , Helicoverpa armigera , Spodoptera frugiperda , Spodoptera litura , and Spodoptera exigua [ 3 , 4 , 5 ], but also shows highly lethal pesticidal activity against other insect pests including thrips, cotton aphids, and two-spotted spider mites [ 6 , 7 , 8 ]. Broflanilide was registered as a commercialized pesticide in China in 2020 and is considered a promising chemical agent for field application to control agricultural pests [ 9 ].…”

Susceptibility and diagnostic concentration for Bacillus thuringiensis toxins and newer chemical insecticides in Spodoptera frugiperda (Lepidoptera: Noctuidae) from China

“…Moths were supplied with 10% sugar water (weight: volume, w/v). Both larvae and moths were maintained at a 26 ± 1 °C temperature, 50–70 % relative humidity (RH), and a photoperiod of 16 h (light): 8 h (dark) (Wang et al 2022b). All field collected populations and the laboratory strain YJ-19 of S. frugiperda were reared in the laboratory under these conditions.…”

“…We used diet-overlay bioassays to measure the concentration–mortality response of S. frugiperda to Bt toxin (Marçon et al 1999) and synthetic insecticide (Wang et al 2022b).…”