昆蟲刺探電位圖譜(EPG)：刺吸式害蟲取食行為鑑定新技術

Abstract

由於無法直接觀察半翅目昆蟲特化口針在植物組織的刺探與穿刺過程，致使研究此類昆蟲的取食行為、對植物損害以及傳播植物病原的相關研究，存在極大挑戰，及至 50 年前所發明昆蟲刺探電位圖譜 (electrical penetration graph, EPG) 監測儀，才克服這些研究上的障礙。如今 EPG 主要以三個方向發展半翅目害蟲整合管理 (IPM) 新策略，包括 (1) 對特定半翅目昆蟲之取食行為與造成植物傷害機制未明時， EPG 是可有效解決的工具；(2) 解決上述問題之後，EPG 可被應用於分析殺蟲劑或拒食劑對害蟲行為所造成的影響，並進一步評估其他化合物對於特定取食行為造成危害與傳病的原因；(3) EPG 能被應用於不同植物品系抗蟲程度的評估，包括基因改造表現生物殺蟲成分的作物。本回顧報告主要目的包括 (1) EPG 的原理以及歷史，特別針對第三代 AC-DC 儀器進行介紹；(2) 以蚜蟲為模式系統，作為瞭解那些波形可自 EPG 獲得；(3) EPG 可應用在臺灣農業的那些需求，特別是對於那些具有經濟重要性的蚜蟲。本文係首次提出三型 EPG 在蚜蟲研究概況的回顧研究報告。 Studying the feeding, plant damage, and transmission (i.e. acquisition, retention, and inoculation) of plant pathogens caused by hemipteran insect pests has always been a challenge. This is primarily because their specialized, piercing-sucking mouthparts, the stylets, perform probing/penetrating action into opaque plant tissues in which the stylets cannot be directly visualized. This challenge was overcome by a technological revolution over 50 years ago; the invention of electropenetrography, or electrical penetration graph (EPG) monitoring, the most rigorous method to identify feeding behaviors of hemipteran crop pests. Today, EPG is used in three main areas for the development of novel integrated pest management (IPM) tactics for hemipteran pests. Firstly, in cases where the fundamental mechanisms of feeding damage or transmission of a plant pathogen are unknown, EPG is instrumental in identifying such mechanisms. Secondly, once the feeding-related causes of damage or pathogen transmission are understood, EPG can be used to demonstrate the effects of insecticides, antifeedants, or other chemical compounds on specific feeding behaviors responsible for the damage or transmission. Thirdly, EPG can similarly identify the effects of resistant vs. susceptible varieties of crop plants, including transgenic plants genetically engineered to express biopesticides. The purpose of this paper is to review: 1) principles and history of EPG, especially development of the new and improved, third-generation AC-DC monitor, 2) what waveforms and types of information can be gained via EPG, using aphid pests as a model system, and 3) how EPG can be applied to the special needs of Taiwanese agriculture, especially for some species of aphids of economic significance in Taiwan. For the first time in print, our review describes and discusses in details the information of all three types of EPG monitors used for researches on aphids.