Recently, resistance to diamide insecticides has been reported in various lepidopteran pests, including Spodoptera exigua. Six field populations and a local population were tested, and results revealed high levels of diamide resistance. We selected a diamide-resistant strain, showing LC₅₀ values 28,950- and 135,286-fold higher than those of a susceptible strain against chlorantraniliprole and flubendiamide, respectively. However, G4946E mutation in the ryanodine receptor, one of the well-known diamide resistance mechanisms, was not found in the tested resistant field populations. Instead, through genome sequencing, we found an I4790M mutation and some InDels, particularly a 29-bp insertion in the neighboring intron that was associated with this resistant allele. By using this distinct region, resistant allele diagnostic primers were designed and applied in a lamp loop-mediated isothermal amplification (LAMP) assay and general PCR. The applicable temperature of the LAMP assay was from 63 to 65 °C for 2 h with four primers. Addition of a loop primer further increased the amplification efficiency. LAMP was feasible with a broad range of DNA concentrations, with a minimum detectable concentration of 100 pg. A DNA releasing method comprising 5 min of incubation at 95 °C allowed DNA detection from some larva and adult samples. The combination of this DNA releasing technique and LAMP resulted in a rapid (up to 100 min) and accurate diagnostic strategy that could be applied to monitor and manage diamide resistance in S. exigua.

近来，在各种鳞翅目害虫中，包括斜纹夜蛾（Spodoptera exigua），已报道了对二酰胺杀虫剂的抗性。对六个田间种群和一个本地种群进行了测试，结果显示出高水平的二酰胺抗性。我们选择了耐二酰胺菌株，显示LC ₅₀分别比对氯氰菊酯和氟苯二酰胺敏感的菌株高28,950-倍和135,286倍。但是，在已测试的抗药性田间种群中未发现兰诺定受体中的G4946E突变（众所周知的二酰胺抗性机制之一）。相反，通过基因组测序，我们发现了一个I4790M突变和一些InDel，特别是与该抗性等位基因相关的邻近内含子的29 bp插入。通过使用该不同区域，设计了抗性等位基因诊断引物，并将其应用于灯环介导的等温扩增（LAMP）分析和常规PCR。LAMP分析的适用温度为63至65°C，使用四种引物进行2小时。添加环引物进一步提高了扩增效率。LAMP适用于广泛的DNA浓度范围，最低可检测浓度为100 pg。DNA释放方法包括在95°C下孵育5分钟，从而可以从一些幼虫和成年样品中检测DNA。这种DNA释放技术和LAMP的结合产生了快速（长达100分钟）和准确的诊断策略，可用于监测和管理猪的二酰胺抗性。S. exigua。