Seed dressing with triflumezopyrim controls brown planthopper populations by inhibiting feeding behavior, fecundity and enhancing rice plant resistance

Abstract

BACKGROUND Triflumezopyrim (TFM), a novel mesoionic insecticide, has high efficiency at a low dosage, and is mainly used to control hopper species. A previous study demonstrated that seed dressing with TFM effectively controlled rice planthopper populations in mechanically transplanted rice fields; however, mode of action for control was unclear. RESULTS The study shows that seed dressing with TFM resulted in elevated levels of oxalic acid, flavonoids, phenolic substances, callose and other compounds associated with Nilaparvata lugens resistance in rice plants, and low TFM residue content in rice plant stem and grain. Host choice behavioral experiments showed that N. lugens females prefer feeding on untreated rice plants. Electrical penetration graph (EPG) data showed that seed dressing with TFM at medium and high doses significantly prolonged the non‐probing period and inhibited phloem ingestion in N. lugens females. These changes led to a significant decrease in female secretion of honeydew, expression of genes encoding vitellogenin and juvenile hormone acid methyltransferase, body weight and longevity, and significantly influenced several physiological parameters resulting in impaired oocyte growth, fecundity and population. Field survey data showed that seed dressing with TFM was efficacious and relatively durable in protecting rice plants from infestation by planthoppers. CONCLUSION This study revealed that seed dressing with TFM enhances rice plant resistance to N. lugens by limiting phloem ingestion and increasing the N. lugens non‐probing period; this leads to reduced fecundity of females and lowers N. lugens numbers in the field. © 2021 Society of Chemical Industry

Seed Priming of Rice Varieties with Decoyinine Improve Their Resistance against the Brown Planthopper Nilaparvata lugens

“…In addition, the weights of female BPHs fed on DCY100-pretreated plants of two rice varieties were decreased significantly (Figure 8), and these results were consistent with those of a previous study [27]. Recent studies have indicated that treating seeds with triflumezopyrim enhanced rice resistance against BPH by inhibiting phloem ingestion, which resulted in the reduced fecundity of females and lowered the population in the field [42,43]. A two-way ANOVA suggested that the effect of DCY treatment on the honeydew excretions and weights of BPHs was greater than rice variety and the interactions between DCY treatment and rice variety (Table 6).…”

Repellency Mechanism of Natural Guar Gum-Based Film Incorporated with Citral against Brown Planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae)

“…The EPG technique is mostly used to study the real-time probing and ingestion behavior of sucking insects, for an insect’s stylet-probing behavior can be recorded by digital signal and afterwards transformed into waveform and then analysis by bundled software. EPG was first applied to research on the feeding behavior of aphids, then widely used in research on the feeding behavior of BPHs [ 13 , 24 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ].…”

Seed Coating with Triflumezopyrim Induces the Rice Plant’s Defense and Inhibits the Brown Planthopper’s Feeding Behavior

“…He et al [8] found that pymetrozine treated rice plants might be distasteful to BPH, observed by a drastic increase in the NP period of electropenetrography (EPG) decreased phloem ingestion. The TFM works by desensitizing the nicotinic acetylcholine receptor [19]. However, pymetrozine interferes with neuroregulation and triggers feeding termination for prick-suck insects, resulting in starvation [8].…”

“…Furthermore, the TFM and related mesoionic insecticides, having native and expressed nAChRs, compete for the same binding site as imidacloprid. Further, several other studies have unfolded the role of TFM as a BPH population controlling agent in China [17], India [18], and Malaysia [19]. The TFM showed an effective response and high efficiency to rice planthoppers with no toxicity to non-target arthropods.…”