Molecular identification of dipteran pests (Diptera: Sciaroidea) from shiitake mushroom SEUNGGWAN SHIN,*†‡ SUNGHOON JUNG,*†‡ HEUNGSIK LEE§ and SEUNGHWAN LEE*†‡ *Insect Biosystematics Laboratory, Seoul National University, Seoul 151-921, Korea, †Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul 151-921, Korea, ‡Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Korea, §Central Post-Entry Quarantine Station, Animal Plant and Fisheries Quarantine and Inspection Agency, Suwon 443-400, Korea Abstract On shiitake farms, mycophagous maggots can cause serious damage by preventing formation of the fruiting body. Recently, these pests have significantly reduced shiitake production in Korea. However, larvae and female adults cannot be identified due to their lack of morphological characteristics. Therefore, farmers and applied entomologists are unable to determine which species is the primary cause of the shiitake damage. In this study, mycophagous flies (colonized larvae) were collected from damaged shiitake farms and subsequently identified by matching identified males with the cytochrome c oxidase subunit I (COI) sequences from the larvae. Divergences of the COI sequences among the species discriminated the clusters clearly, and the mycophagous pests were identified as Camptomyia corticalis and C. heterobia. Interestingly, these two species coexisted under the bark of shiitake oak bed logs. Keywords: Camptomyia corticalis, Camptomyia heterobia, COI barcoding, Shiitake mushroom pest Received 14 December 2011; revision received 27 November 2012; accepted 29 November 2012 Introduction The shiitake Lentinula edodes (Berk.) Pegler 1976 (Agari- cales: Marasmiaceae) is an edible and medicinal mush- room grown in Far East Asia (Mimura et al. 1998; Hirasawa et al. 2000; Brauer et al. 2002; Shimada et al. 2002). It is cultivated widely in Asia as well as in Holland, the United States and Canada (Gold et al. 2008), as one of most-cultivated types globally, second only to Agaricus [white button mushroom and portobel- lo mushroom (Gold et al. 2008)]. In Asian countries, the commercial shiitake is generally cultivated in green- houses in which the temperature, brightness and humidity are controlled. Recently, in many shiitake nurseries of Korea, farmers have experienced a serious loss of crops and have even had to abandon mushroom farming due to severely damaged bed logs (Kim et al. 2010a; Shin et al. 2011). The damage was caused by the propagation of a large number of mycophagous dipteran larvae (Cecidomyiidae and/or Sciaridae) and green fungi (green mould disease) Gliocladium viride Matr. 1893 (Hypocreales: Hypocreaceae) (Kim et al. 2010a). Thus, these flies are believed to be an important pest in shiitake bed logs; however, it remains uncon- firmed due to the lack of information regarding larval morphological characteristics (Panelius 1965; McAlpine 1981; Shin et al. 2011; Sutou et al. 2011) (Fig. 1A). These mycophagous flies can be hardly separated by the morphological characteristics of adult males, and larval samples must be reared to adulthood to get the adult male specimens (Panelius 1965; McAlpine 1981; Gagne 2004). Consequently, DNA-based methodologies could be used to identify the immature and female speci- mens (Boehme et al. 2010). Recently, ‘DNA barcoding’ has been used for pest monitoring and quarantine issues (Armstrong & Ball 2005; Ball & Armstrong 2006; Hebert & Ratnasingham 2007). Its utility has been confirmed in several hexapod orders; e.g. Coleoptera (L€ obl & Leschen 2005), Diptera (Scheffer et al. 2006; Smith et al. 2006; Rivera & Currie 2009), Ephemeroptera (Ball et al. 2005), Hemiptera (Foot- tit et al. 2008; Kim et al. 2010b; Lee et al. 2010; Jung et al. 2011), Hymenoptera (Smith et al. 2008), and Lepidoptera (Hebert et al. 2003; Hajibabaei et al. 2006). The cyto- chrome c oxidase subunit I (COI) DNA barcodes of Cecidomyiidae have been studied and applied to gall- making species, which are pests of live plants (Kolesik & Veenstra-Quah 2008; Uechi et al. 2011; Veenstra et al. 2011; Mathur et al. 2012). Correspondence: Seunghwan Lee, Fax: +82 2 873 2319; E-mail: seung@snu.ac.kr © 2013 Blackwell Publishing Ltd Molecular Ecology Resources (2013) 13, 200–209 doi: 10.1111/1755-0998.12057