Diagnosis of Liposcelis entomophila (Insecta: Psocodea: Liposcelididae) based on morphological characteristics and DNA barcodes Qianqian Yang a , Zuzana Ku  cerová b, * , Zhihong Li a, * , Irma Kalinovi  c c , Václav Stejskal b , George Opit d , Yang Cao e a Department of Entomology, College of Agronomyand Biotechnology, China Agricultural University, Yuanmingyuan West Road 2, Beijing 100193, PR China b Crop Research Institute, Drnovská 507, 161 06 Prague 6, Czech Republic c Faculty of Agriculture in Osijek, Department for Plant Protection, University of Josip Juraj Strossmayer in Osijek, Trg Sv. Trojstva 3, 31000 Osijek, Croatia d Department of Entomology and Plant Pathology, Oklahoma State University,127 Noble Research Center, Stillwater, OK, USA e Academy of State Administration of Grain, No. 11 Baiwanzhuang Street, Beijing 100037, PR China article info Article history: Accepted 25 October 2011 Keywords: Storage pests Electron microscopy mtDNA COI Diagnosis Psocoptera abstract Liposcelis entomophila infests stored grain and is one of the most important psocid species worldwide. Six geographically isolated strains of L. entomophila from Asia, Europe, and United States of America (USA) were compared based on morphological attributes and by molecular methods. Decisive characters of morphological diagnosis were studied using body size measurements and Scanning Electron Microscopy (SEM). Molecular identification of the six strains was performed via identification of DNA sequence similarities and phylogenetic analyses based on a 655-bp fragment from the 5 0 end of the standard mitochondrial gene cytochrome c oxidase I (COI) barcode region. The results showed that both morphological and molecular approaches were able to accurately identify this species. Kimura-2-Parameter (K2P) divergence between geographically isolated strains was on average 1.75% for the COI sequence. Phylogenetic analyses revealed that sequences of L. entomophila strains’ COI barcodes formed clusters with tight cohesion that were clearly distinct from those of allied species. Ó 2011 Elsevier Ltd. All rights reserved. 1. Introduction Psocids, which include a number of domestic and stored prod- ucts pests, pose an increasing threat to stored products worldwide (Rees, 2004) and are commonly found in a wide range of synan- thropic habitats, such as processed and unprocessed dry foods in households, granaries, and product warehouses (Rees, 2004; Turner, 1994). In the last two decades, psocids have become an increasingly serious problem not only in grain storages, warehouses with bagged commodities but also in collection centres and export terminals (Opit and Throne, 2008). In addition, psocids have become stored product pests of considerable economic importance, contaminating foods and negatively affecting the quality and safety of food in various parts of the world (Nayak, 2006). Additionally, these pests are a potential cause of respiratory and dermatological allergies (Musken et al., 1998; Patil et al., 2001; Turner, 1994), transferring microorganisms to humans. They can transmit bacteria and fungi both on the surfaces of their bodies and also internally (Kalinovi c et al., 2006). In recent years, the importance of studying psocids has been enhanced by the fact that they develop rapid resistance to insecticides, phosphine and controlled atmosphere treatments (Cao et al., 2003; Ding et al., 2002; Nayak and Daglish, 2007). Traditional diagnosis of psocids from the genus Liposcelis (Liposcelididae) through identification of specific morphological characters is difficult, especially in the case of juvenile stages; this method requires specialized taxonomic knowledge and microscopy techniques (Ku cerová et al., 2009; Lienhard, 1990). DNA-based approaches offer an effective complement to traditional taxo- nomic methods and are currently widely employed for insect species identification. Molecular diagnostics have been applied to the identification of the Liposcelis species; for example, PCR-RFLP (Restriction Fragment Length Polymorphism) analysis was used for rapid discrimination of four common species of catalogued Liposcelis from China and the Czech Republic (Qin et al., 2008), and 16S rDNA has been proven to be effective in defining intra-species diversity of Liposcelis bostrychophila Badonnel (Li et al., 2011). DNA barcoding is a DNA-based species identification system which offers a promising supplemental technique with standard- ized portions of the genome (Hebert et al., 2003). The most * Corresponding authors. E-mail addresses: kucerova@vurv.cz (Z. Ku cerová), lizh@cau.edu.cn (Z. Li). Contents lists available at SciVerse ScienceDirect Journal of Stored Products Research journal homepage: www.elsevier.com/locate/jspr 0022-474X/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.jspr.2011.10.007 Journal of Stored Products Research 48 (2012) 120e125