主要农业害虫对茚虫威的抗性现状及其治理策略

Status of the resistance of agricultural insect pests to indoxacarb and management strategy

茚虫威属于噁二嗪类杀虫剂,与大多数杀虫剂不同的是其进入害虫体内需要经活化代谢转变成N-去甲氧羰基代谢物(decarbomethoxylated metabolite,DCJW)后不可逆地阻断钠通道,进而发挥杀虫活性。茚虫威由于其作用机制不同于常见的使钠离子通道延迟关闭的菊酯类药剂而被广泛用于鳞翅目和一些同翅目、鞘翅目害虫的防治。抗药性是任何杀虫药剂使用后面临的问题,茚虫威也不例外,许多害虫对其产生了不同程度的抗性。昆虫对茚虫威产生抗性的机制包括酯酶活性、谷胱甘肽S-转移酶(glutathione S-transferase,GST)和P450活性的增加以及分子靶标F1845Y、V1848I、L1014P的突变,这些对茚虫威抗性机制的研究基本都是基于抗性种群和敏感种群开展的,需要进一步验证其对抗性研究的贡献度。针对我国田间害虫种群对茚虫威的抗性现状,及时实施对茚虫威有效的抗性治理是迫切的。对于茚虫威的抗性治理除了传统的杀虫药剂轮用、混用外,需要利用其作用机制特点开展抗性治理策略研究。一是充分利用其活化代谢的特点,开展组合药剂的研究应用;二是菊酯类药剂和茚虫威的作用机制均与钠离子通道有关,但是前者是使钠离子通道关闭延迟,而后者是阻断钠离子通道,开展相关基础研究,使菊酯类药剂与茚虫威合理地用于抗性治理中。本文综述了茚虫威的抗性现状、抗性机制与交互抗性、茚虫威的抗性风险评价,针对茚虫威的抗性特点提出了抗性治理策略。

Indoxacarb is an oxadiazine insecticide, which is bioactivated by insect esterase/amidase enzymes to a decarbomethoxylated metabolite(DCJW) in insect pests. The bioactivated DCJW metabolite can irreversibly block sodium channels to exert insecticidal activity. Indoxacarb is widely used in the control of lepidopteran, some homopteran and coleopteran pests, because its action mechanism is different from that of common pyrethroid insecticides. The development of insect resistance is inevitable along with the application of insecticides. Some insect pests have developed various degrees of resistance to indoxacarb. The indoxacarb resistance was found to be related to the increased activity of esterase, glutathione S-transferase(GST) and P450, and the mutation of the molecular targets F1845 Y,V1848 I and L1014 P in the above insect pests. These resistance mechanisms were uncovered mainly based on the comparison between resistant and susceptible populations;however, further work is needed to verify their contribution to the indoxacarb resistance in various insect pests. The effective management strategy requires to be developed in view of the current status of the resistance of insect pests to indoxacarb in China. In addition to the traditional rotation and application of mixed insecticides, it is useful to develop new resistance management strategies based on its activation modes. Moreover, the action mechanism of pyrethroid insecticides and indoxacarb are all related to the sodium ion channels:pyrethroids delay the closure of sodium ion channels, while indoxacarb blocks sodium ion channels.Therefore, the related basic researches should be carried out for reasonable application of pyrethroids and indoxacarb to the resistance management. This article reviews the current resistance status of indoxacarb, resistance mechanisms and cross-resistance, as well as the resistance risk of indoxacarb, and some suggestions for resistance management strategy based on the characteristics of indoxacarb resistance were proposed.