Rapid Identification of the Spruce Bark Beetle <i>Ips typographus</i> (Linnaeus) Basing on a New Amplification and Analysis Platform

Abstract

Insects, one of the major disturbance agents, are regarded as a big challenge to forests. Bark beetles (Coleoptera: Curculionidae: Scolytinae) are among the most destructive pests around the world. The European spruce bark beetle <i>I. typographus </i>(Linnaeus) is considered the most dangerous species to mature spruce forests throughout Eurasia. In order to improve efficiency, accuracy, and operability of identification, a rapid, simple, highly sensitive and specific screening method is in urgent need. In this study, a rapid classification approach for <i>I. typographus</i> was established based on the enzyme-mediated duplex exponential amplification (EmDEA) amplification and analysis platform. The method development process consists of target gene selection, primer design, primer screening, and method validation. Parameter analysis demonstrated that this new method has a detection limit of 1.96×103 copies/μL, which is comparable to conventional molecular tools such as PCR. Stable repeatability and high specificity were confirmed by testing 5 samples of <i>I. typographus</i> and 4 related beetles. Besides, this screening protocol was easy to use, and could be completed in 30 min. With the advantage of isothermal amplification, this method could be further applied in non-laboratory scenarios such as port rapid screening and wild survey. This rapid screening method for <i>I. typographus</i> is believed to assist precise prediction and efficient prevention of exotic insect species.