The pea leafminer fly, Liriomyza huidobrensis Blanchard (Diptera: Agromyzidae), is an emerging pest in Korea. High population and heavy damage of this pest were observed from potato fields in the southern part of Korea in 2012. Morphological and genetic evidence confirmed the species as L. huidobrensis. The infestation was expanding throughout the country and a rich complex of parasitoid was recognized. From the exclusion study, high density infestation of leafminers reduced yield among potato varieties (Chubeak, Seohong, Goun, Dejima, and Sumi). Higher leaf damage was evident in the lower part of plants. In olfactory bioassay and feeding preference tests, leafminers choosed the Goun variety most. Given the six constant temperatures, the developmental time from egg to adult significantly decreased with increment of temperatures. From the insecticide toxicity tests, abamectin and lepimectin and spinetoram were found effective against immature stages, while cartap hydrochlorid (Neonicotinoid) was against adult insects. Overall, these studies help to pave the ways for managing this new invasive pest.

Liriomyza leafminer flies comprise a pest group that causes both considerable economic losses and serious quarantine problems. To investigate Liriomyza spp. abundance and distribution along with natural enemies, we surveyed of leafminer (LM) species and its natural enemies (NE) on potato crop from 146 farmers’ field in the potato growing provinces during 2015. Sweeping (10 sweeps/ field) and visual inspection were employed within 5 minute-walking distance, and damaged leaflets (10 leaflets/ field) were collected in each field. Leafminer species were identified by morphological, and its NE was identified by morphological and molecular techniques. L. huidobrensis was the most dominant Liriomyza species. Distribution of L. huidobrensis on potato fields was expanding. Highest potato fields were infested with leafminer in southern parts of country. Highest rate (100%) field damage was recorded in Miryang, Namwon, Henam, and Boseong. Overall, NE species collected constituted of 4 families and 18 and 20 species in sweeping, and damaged samples respectively. There was a rich complex of parasitoid species including 20 species (13 species of Eulophidae family). The endoparasitoid, Braconid sp., Ganaspidium sp., and ectoparasitoid, Diglyphus isaea were dominant species in sweeping. While Diglyphus isaea, Hemiptarsenus varicornis, and the Braconid sp. were most dominant species collected from damaged samples. The number and diversity of parasitoid species in potato crop in Korea provides insight into the development of integrated control strategies of invasive LM pests in the field, and glasshouse crops.

The potato leafminer fly, Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae) is a polyphagous pest attacking many vegetables and ornamental plants. We found L. huidobrensis were infesting potato crop in Miryang and Goreyong in 2011. Five potato (Solanum tuberosum) varieties (Ghowun, Daeri, Sumi, Chubeak, and Seohong) were tested for the preference of L. huidobrensis. In the olfactormeter bioassay, leafminers chose the Ghowun variety most (55%) followed by Sumi (18%). Remaining 3 varieties were chosen less than 10%. When leafminers choose and move toward the preferred variety, movement speed was faster. In the plant choice test in the laboratory, as expected, Ghowon was the most chosen but the choice of the other 4 varieties was not different. The same pattern as found in the plant choice test conducted in the greenhouse. Feeding frequency was the highest in Ghowun variety followed by Sumi > Daeri = Seohong > Chubaek in the laboratory test but Ghowun > Sumi > Chubaek > Daeri = Seohong in greenhouse test. When measured in 2 weeks after release, plant damage rates and number of mines were in congruence to the preference results. Further study is needed to clarity the factor responsible for the choice of the plants and also the ways to manage this new pest.

Liriomyza leafminers comprise a pest group that causes both considerable economic losses and serious quarantine problems. In recent years, the pest status of Liriomyza sp. has changed in Korea, as well as other areas of the world. Potato field survey was conducted in 157 farmers’ field from five provinces during 2011 and 2012. Foliar insect monitoring was done within 5 minutes walking distance by visual inspection. Leafminer fly and parasitoids were collected by sweeping net (10 sweeps/field) in same field in each time. Overall, potato insect species collected constituted of 7 orders, 22 families and 42 species. Aphis gossypii was most abundant species in all the locations. However, Potato tuber moth, Pthorimaea operculella was only dominated species in Boesong (Jellanam-do). L. huidobrensis was the first record infesting the potato in Korea. Liriomyza huidobrensis was only found from Miryang (Gyeongsangnam-do) and Goreyong (Gyeongsangbuk-do). There is a rich complex of parasitoid species; 18 species of parasitoids were recorded. Most parasitoid species (11) belong to the Eulophidae family. The most abundant species were the ectoparasitoid, Diglyphus isaea and endoparasitoid, Ganaspidiumsp. The number and diversity of parasitoid species in potato crop in Korea provides insight into the development of integrated management strategies of leafminer pests.