Revalidation of morphological characteristics and multiplex PCR for the identification of three congener invasive Liriomyza species (Diptera: Agromyzidae) in China

Ya-Wen Chang; Jing-Yun Chen; Si-Zhu Zheng; Yuan Gao; Yunfang Chen; Yanfeng Deng; Yu-Zhou Du

doi:10.7717/peerj.10138

Revalidation of morphological characteristics and multiplex PCR for the identification of three congener invasive Liriomyza species (Diptera: Agromyzidae) in China

PeerJ. 2020 Oct 30:8:e10138. doi: 10.7717/peerj.10138. eCollection 2020.

Authors

Ya-Wen Chang¹, Jing-Yun Chen^{1

2}, Si-Zhu Zheng², Yuan Gao², Yunfang Chen², Yanfeng Deng², Yu-Zhou Du^{1

3}

Affiliations

¹ College of Horticulture and Plant Protection & Institute of Applied Entomology, Yangzhou University, Yangzhou, China.
² Suzhou Customs, Suzhou, China.
³ Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou, China.

Abstract

Due to varietal differences, diminutive size, and similar morphological characters, it is difficult to classify and identify Liriomyza spp., a genus comprised of economically-important, highly-polyphagous insect pests. In this study, we reconfirmed the morphological characteristics of three closely-related invasive leafminers, L. trifolii, L. sativae, and L. huidobrensis. Morphological results showed that characteristics imparted by the male genitalia were the most reliable morphological features for identification. The colors exhibited by vertical setae were variable among species, and the ratio of the length of the ultimate section of vein CuA₁ divided by penultimate section also varied within species. Although the patterns of abdominal tergites were diverse among Liriomyza spp., L. trifolii exhibited a unique pattern with a yellow patch at the 5^th black visible tergite; this pattern can be profiled as a prominent characteristic for morphological identification. In order to identify the three Liriomyza spp. quickly and accurately, we developed an improved molecular identification method using multiplex PCR based on the gene encoding mitochondrial cytochrome oxidase I (COI); this method enabled direct identification based on the size of amplified products. The results of this study provide a valuable reference for the identification of Liriomyza spp., which will ultimately improve our ability to control individual species.

Keywords: Abdominal tergites; Morphological characteristics; Multiplex PCR; Species identification; COI; Liriomyza.

Grants and funding

This research was funded by the Suzhou Customs Science and Technology Program (2020SZKY05), the earmarked fund for Jiangsu Agricultural Industry Technology System (JATS [2019] 331), the Jiangsu Science and Technology Support Program (BE2014410), and the Basic Research Program of Agricultural Application of Suzhou (SNG201602). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.