Among several insect pests in the potato fields, Liriomyza huidobrensis, pea leafminer, is emerging as a new threat to potato plants. Adult females damage the host mesophyll cells host due to ovipositor probing. After egg hatching, the eclosing larva also damage the leaf by mining the mesophyll and causing tissue death. Despite the importance of leafminer in potato production, there is no information available regarding its resistance level to potato cultivars in Korea. Using choice test, 21 potato cultivars consisting of 11 early-maturing, 6 mid-maturing and 4 late-maturing cultivars were evaluated the resistance to pea leafminer in the greenhouse and field condition. In this test, significant differences for resistance were observed. High levels of resistance to leafminers were obtained from cvs. Namsuh, Seohong, Jayoung and Superior. These resistant cultivars might be useful in future breeding programmes.

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.

To assess actual foliage damage due to potato leaf miner, Liriomyza huidobrensis (Blanchard), commercial potato pockets of Lalitpur, Kathmandu, Bhaktapur, Kavrepalanchwok, Sindhupalchwok and Makwanpur districts of Mid-Nepal were surveyed in 2009. Percent foliage damage analysis and ANOVA (with unbalanced frequency distribution) of multiple regressions of different factors were done to evaluate the level of damage and factors significantly influencing damage. Damage level was found more in lower altitudes (790-1568 meters above sea level) than in higher altitudes (1560-2610 meters above sea level). Similarly, lower leaves were more damaged than the upper ones. So, altitude and plant age were two factors influencing damage by test insect. Since the pest is becoming severe and can withstand chemical sprays, it is imperative to develop suitable IPM technique against this insect. Similarly, strict quarantine and awareness campaign against this insect pest are crucial to check its migration to virgin potato pockets.

The pea leafminer fly, Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae), is a polyphagous pest attacking wide range of field and greenhouse crops and ornamental plants. Surprisingly, localized outbreaks with high population and heavy unique damage of leafminers were observed from the field survey of potato fields in the southern parts (Miryand and Goryeong) of Korea in 2012. L. huidobrensis was the responsible for those potato damages based on the morphological and genetic characteristics. Then after, it added a one more emerging species in Korean Liriomyza account. Infestation of L. huidobrensis was expanding and reported in major potato growing areas of the country. Genetic evidence showed the close relationship with Chinese L. huidobrensis population, so it might be invaded from China. As a new emerging pest, very few informations relative to this pest are available in Korean prospective. There is also significant potential for it to widen its distribution, as the Korean Peninsula is a hot spot of climate change, particularly global warming. There are a lot of challenges uprooting infront of researchers and growers. It is demanded to explore new secrets and to be ready to tackle of this invasive pest, L. huidobrensis.

The development of Liriomyza huidobrensis (Blanchard), an economic pest of wide range of field crops and ornamental plants, was studied under laboratory conditions at six constant temperatures (10, 15, 20, 25, 27 and 30oC). The total development period decreased with increasing temperatures between 15 and 27oC. In 10oC, eggs did not hatch and in 30oC, pupa did not survive. So, it may be assumed that these temperatures fall outside the development. Linear regression was used to describe the relationship between development rate and temperature. For total immature development (egg to adult) required 250 degree-days (DD) above the threshold of 9.75oC. The developmental data were fitted to a nonlinear temperature-dependent model (Lactin-1) for best described of development. Development rates of males and females did not differ in 20 and 25oC. High immature mortality was recorded in 27oC. Sex ratio of the surviving individuals was 0.62 from this study. Thermal requirements and temperature thresholds can be used to forecast the occurrence, number of generations and population dynamics of L. huidobrensis.

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.

Liriomyza species are the major pests of greenhouse and field crops. It was as minor pests in past, but the pest population increased rapidly such as L. trifolii, L. huidobresnsis and L. sativae during recent years is attributed to application of ineffective insecticides and developed insecticide resistance. This study was carried out to determine the efficacy of insecticides groups, Anthranilic diamide, Biopesticide, Carbamate, Neonicotinoid, Organophosphate, Pyrethroid and Oxadiazine, recommended for the control of leafminer species in Korea. Bioassay tests were done on first, third larval stages and adults under glasshouse and laboratory conditions respectively. The result showed significant differences in toxicity among the tested insecticides. The mortality of abamectin and lepimectin and spinosad were higher (>50%) in larvae stages. Etofenprox insecticide was not effective on larvae stage. The toxicity of Cartap hydrochlorid (Neonicotinoid) was higher (100%) in adult insects, followed by thiamethoxam, etofenprox and indoxacarb. Abamectin and lepimectin showed the decreasing toxicity level as insect stage developed. Abamectin showed least toxicity (26.67%) in adult stage. Spinetoram and emamectin benzoate showed higher toxicity (>50%) in all the insect stages tested. It could be suggested that abmectin and lepimectin have high efficiencies on control of larvae. However, spinosad and emamectin benzoate has higher potential on the control of both larvae and adult insects.

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.

Population dynamics of American serpentine leafminer, Liriomyza trifolii, were modeled and simulated to compare the temperature effects of air and tomato leaf inside greenhouse using DYMEX model simulator. The DYMEX model simulator consisted of series of modules with the parameters of temperature dependent development and oviposition model of L. trifolii from pre-published data. Leaf surface temperature of cherry tomato leafs was monitored according to three tomato plant positions using an infrared temperature gun. Air temperature was monitored at same three positions using a self-contained temperature logger. Data sets of observed air temperature and average leaf surface temperatures were prepared, and incorporated into DYMEX simulator to compare the effects of air and leaf surface temperature on population dynamics of L. trifolii. The number of L. trifolii larvae was counted by visual inspection in tomato plants to verify the performance of DYMEX simulation. The egg, pupa, and adult stage of L. trifolii were not counted due to its availability of visual inspection. Based on correlation analysis, L. trifolii was affected greatly by the leaf temperatures, rather than air temperatures.

Economic injury levels and economic thresholds were estimated for the american serpentine leafminer (Liriomyza trifolii) on greenhouse eggplant. Liriomyza trifolii density was increased until the late June and decreased after the July in innoculation on may 17. Growth of an aerial plants and fruits were not different in treatment respectively. But total number of fruits and yields were decreased on higher inoculation density. Whereas the rate of yield loss was increased. The rates of damaged leaf by L. trifolii were increased on higher inoculation density and the peak was 65%. The number of commodity fruits and the rates of commodity fruit were become lower than non-treatment (72.2%). The rates of damaged leaf area were 5.3, 11.7, 19.7, 25.7% on inoculation densities and the rates of yield loss were 0.6, 4.8, 9.8, 14.7%, respectively. There existed close correlation between rate of yield loss and inoculation density (Y = 0.76779X + 0.298354, R² = 0.9599). Considerated of the results, the economic injury levels of L. trifolii on eggplant greenhouse was 6.1 adults per 4 plant and the economic thresholds was 4.9 adults per 4 plant

Biological control of Liriomyza trifolii (Burgess) using Diglyphus isaea (Walker) has been evaluated in tomato greenhouse, for three seasonal culture types: spring type (March-July), summer type (June-October) and autumn type (July-December). For spring type, totally 5.8 individuals/㎡ of D. isaea has been released at six times from late April, when the density of L. trifolii was about 1.0 individuals/plant. Corrected mortality of Liriomyza trifolii caused by parasitoids was 97.6% at early July, and the proportion of D. isaea was 88.9% of all parasitoids collected in the greenhouse. In the case of summer type, totally 1.8 individuals/㎡ of D. isaea has been released at five times from early July, when the density of L. trifolii was about 0.4 individuals/plant. Corrected mortality of L. trifolii caused by parasitoids was 84.4% during the whole season, but the proportion of D. isaea was very low (only 13.8%). Immigrating parasitoids such as Chrysocharis penthus were synchronized to control the leafminer in the greenhouse. For autumn type, totally 2.7 individuals/㎡ of D. isaea has been released at four times from mid September, when the density of L. trifolii was about 0.7 individuals/plant. Corrected mortality of L. trifolii caused by parasitoids was 85.7% at mid December, and the proportion of the D. isaea was 83.4%.

Experiments have been performed to investigate biological characteristics of Diglyphus isaea (Walker), an ectoparasite of Liriomyza trifolii (Burgess). At 25℃, development time of D. isaea was estimated as 1.3 days for eggs, 4.5 days for larvae and 6.3 days for pupae. Adult longevity was 25.1 days, and a female adult could lay 305.3 eggs throughout its lifetime. Number of L. trifolii parasitized or killed by the wasp was 962.2 individuals/adult. Most of all parasitized or killed larvae were identified as third instar. With 20% honeyed water as food source, half of the adults could survive 180 days at 5℃, 150 days at 10℃, and 90 days at 15℃. After storing at 10℃ with absolute honey for 30 days, 70 days and 140 days, a female adult in room temperature laid eggs 190.8 individuals, 104.0 individuals and 89.4 individuals, respectively.

The antennal receptors of the adult male and female of the American leafminer, Liriomyza trifolii (Diptera: Agromyzidae) was studied using the scanning electron microscopy. This antennal receptors were developed to accept the chemical or mechanical signal in the environment. The antennae of L. trifolii is 317.52 ㎛ long and composed of the scape, pedicel, funicle, arista. Antennae located between compounds eye on the middle in the head. The result of SEM observation, four types of receptors were characterized and grouped into morphological classes: Trichoid, Basiconic, Coeloconic, Chetiform sensilla. Trichoid sensilla are located on the all segment. As a rule, female is more than male. This sensilla are long and slender hair with straight or slightly curved, and taper to a sharp point apically. Basiconic sensilla are observed only on the funicle. The number of basiconic sensilla in male and female are almost same in both sexes. This sensilla are long and thick hair with stright or slightly curved, and taper to a blunt point apically. Coeloconic sensilla are observed only on the funicle. This sensilla were showed a finger-like projections the peg apex. The number of basiconic sensilla in male and female are almost same in both sexes. Chetiform sensilla are located on the all segment. This sensilla are needle-like, tapering sharply. Pedicel are more than scape. The number of Chetiform sensilla in male and female are almost same in both sexes.

담배거세미나방의 유충에 처리된 살충제의 아치사농도( 및 )가 용발육, 성충수명 및 산란에 미치는 영향을 조사하였다. 용기간은 무처리의 암컷과 수컷에서 각각 6.9일과 8.0일, 살충제 처리에서 각각 7.2-7.6일과 8.3-8.6일로 무처리보다 살충제 처리에서 길었으나 살충제의 종류 및 아치사농도에 따른 유의한 차이는 없었다. 우화율은 무처리에서 88%, 살충제 처리에서 약 79-95%로 약제처리유무 및 아치사농도 처리에간 뚜렷한 경향이 없었으며, 특히 chlo.fenapyr-bifenthrin 및 ethofenprox처리에서 91.0% 이상의 높은 우화율을 나타내었다. 성충수명은 무처리의 암컷과 수컷에서 각각 7.7일과 7.9일, 살충제 처리에서 각각 7.1-8.4일과 7.7-9.0일로 hexaflumuron-chlorpyrifos의 처리에서 가장 길었던 것을 제외하면, 살충제 처리유무 및 농도에 따른 유의한 차이는 없었다. 총 산란수는 무처리에서 1,010개, 살충제 처리에서 778-948개로 살충제 처리유무에 따른 차이는 있었으나, 살충제의 종류 및 농도에 따른 유의한 차이는 없었다. 따라서 담배거세미나방의 용기간 및 산란은 유충에 처리된 살충제의 아치사농도처리에 의해 영향을 받았다.