Liriomyza leafminer flies comprise a pest group that causes both considerable economic losses and serious quarantine problems. We reported for the first time of the infestation of field crops by this invasive leafminer L. huidobrensis in Korea in 2012. Distribution survey of leafminer flies and other insect pests on potato crops along with associated natural enemies was conducted from 378 farmers' field in most of the potato growing provinces during 2011, 2012 and 2013. Sweeping (10 sweeps/field) and visual inspection were employed within 5 minute-walking distance each field. For damage rate was also calculated for each field. Ten mined leaflets were investigated for parasitoid species identification. Leafminer flies were identified by morphologically and molecular. However, parasitoid species were only morphologically identified. All the leafminer flies collected were identified as L. huidobrensis. No leafminer flies infested fields were recorded in Boseong (Jeollanam-do) in 2011. L. huidobrensis infested fields with unique crop damage symptoms were found only in Miryang and Goryeong (Gyeongsangnam-do) in 2012. There was significant different in leafminer infested fields among the surveyed locations in 2012 (f=85.73, df=5, 127, P<0.0001). Higher damaged (100%) potato fields were recorded in Miryang. Similarly, the leafminer infested potato fields were significantly different among the surveyed locations in 2013 (f=36.77, df=19, 201, P<0.0001). Highest damaged rates (100%) were recorded in all the surveyed locations of Gyeongsangnam-do. Increasing distribution expansion pattern of L. huidobrensis was found. Distribution covers from southern parts to northern parts of the country. The study on rate of distribution and factors responsible in rapid distribution of L. huidobrensis in Korea are demanded.

• Rameswor Maharjan(Department of Bioresources Science, Graduate School, Andong National University)
• Chuleui Jung(Department of Bioresources Science, Graduate School, Andong National University)