고랭지농업은 고도가 높은 지대에서 이루어지는 농업을 총칭하는데, 상대적으로 낮은 연평균 기온과 높은 강수량 등의 환경적 특성으로 인하여 독특한 농업 해충군을 가지고 있다. 강원도를 중심으로 재배되는 씨감자와 고랭지 배추 등이 대표적인 작목인데, 최근 엽채류, 아마란스 등 신소득 작물과 과수까지 그 범위가 점차 넓어지고 있다. 이러한 고랭지농업 해충은 기후변화에 매우 민감한데, 고령지농업연구소에서는 그에 대응하는 방제 전략을 개발, 연구하고 있다. 살충제 저항성 관리 및 돌발해충 방제, 기후 변화에 따른 해충군의 분포 확산, 개체군의 변화 등은 물론 고랭지농업만이 갖는 여러 유용 곤충, 미생물 자원에 대해서도 연구하고 있다. 이러한 연구 분야와 관련 성과물, 앞으로의 연구 방향에 대하여 논의하고자 한다.

최근 파밤나방 등 다양한 나비목 해충에서 diamide 계통의 살충제 (IRAC group 28)의 저항성이 많이 보고가 되고 있다. 국내에서도 이미 배추좀나방과 파밤나방의 저항성이 보고되었는데, 본 연구에서 사용된 강릉에서 2018년 채집한 파밤나방의 경우 Chlorantraniliprole에 대하여 감수성 대비 2,500배 이상의 높은 저항성을 나타냈다. 추천 농도 처리 시 30% 이하의 방제가를 나타냈으며 Cyantraniliprole, Cyclaniliprole, Flubendiamide에서 높은 교차저항성을 나타냈다. 이 저항성 집단에서 diamide 계통 살충제의 작용점인 ryanodine receptor에 이미 보고된 G4946E 돌연변이는 발견되지 않았으나 새로운 I4760M 돌연변이를 발견하였는데, 2014년 배추좀나방에서 보고된 돌연변이와 위치가 동일하였다. 따라서 I4760M 돌연변이는 파밤나방에서 diamide 저항성에 관여 할 것으로 판단한다.

Insecticide Resistant Management (IRM) and Positive List System (PLS) is the main keyword in current insect pest management. So we are trying to develop a integrated insect pests control prescription issuing system based on big data which linked National Crop Pest Management System (NCPMS). To manage the insecticide resistance, IRAC suggest some tips for effective control : choosing the effective insecticide and alteration of these insecticides based on MOA. Then, how to distinguish the effective or non-effective insecticide. Until now, bioassay is the right answer. However that is time-consuming, labor-intensive and costly process. So we have been steadily advancing molecular based insecticide resistance diagnosis for supporting and/or substitution of classical bioassay. And it will link to PLS. Here we discuss more detailed methodology of molecular based insecticide resistance diagnosis and its application for the insect pests control prescription issuing system.

Plants of the Salicacea genus have in common that they utilize phenolic glycosides, so called salicinoids, as protection against leaf chewing herbivores. The caterpillar Cerura vinula only feeds on poplar and willow trees that belong to the family of Salicacea. For this reason, Cerura vinula is viewed as a specialist herbivore that is adapted to the salicinoid defense. Taking advantage of chemical and biochemical techniques we want to trace the salicinoid metabolism pathway, the location of transformation and the involved enzymes. To gain insights into the salicinoid metabolism the caterpillars were put on a specially designed diet. It consisted either of one salicinoid in large excess or one 13C labelled compound, applied together with fresh poplar leaves. As a next step, we are going to identify the new compounds formed in the caterpillar by MS and NMR techniques. To determine the location and mechanism of the transformation we started with a dissection of the caterpillar and a check of the tissue pH value. Afterwards, we incubated the midgut, hindgut and salivary gland tissues with salicin as model substrate and analyzed the transformation products by LC-MS. The transformation products resulted from deglycosilation of the substrate and consecutive oxidation and conjugation of the aglycon. With the gained knowledge we then aimed to identify the enzymes, which are involved in the metabolism. We successfully proofed the existence of glucosidases in the midgut by isoelectric focusing and incubation of the gel with the model substrate 4-methylumbelliferyl β-D-glucopyranosid. Additionally, we performed RNA sequencing on the caterpillar tissue. The transcripts and enzymes involved in the salicinoid metabolism are currently analyzed. During our studies we could determine the mid gut as the place for the deglycosilaton, oxidation and conjugation of salicinoids. Further we identified a new for Cerura vinula undescribed metabolite and proofed the presence of β-glucosidases in the midgut.

진딧물은 감자에 다양한 바이러스병을 옮기는 대표적인 매개충이다. 따라서 감자밭으로 날아오는 진딧물을 방제하는 것은 매우 중요하다. 비래진딧물의 종류, 비래시기와 비래량, 바이러스 보독률 및 진딧물의 겨울철 월동기주를 구명하기 위하여 강원도 고랭지의 씨감자 생산지역 3곳 을 중심으로 진딧물 비래양상을 조사하였고, 비래초기부터 6월 하순까지 날아오는 진딧물의 잎말림바이러스(PLRV) 보독 여부를 조사하였다. 또한 진딧물의 이동방향을 따라 57종의 수목류 가지와 수피를 채집하여 월동중인 진딧물 알의 존재 여부를 조사하였다. 강릉 왕산 지역과 홍천 내 면 지역의 여름기주 비래최성기는 모두 6월 중순이었고 평창 횡계 지역은 5월 하순으로 나타났다. 겨울기주로 날아가는 비래최성기는 3개 지역 모두 10월 상순이었다. 비래진딧물의 2.8%가 PLRV를 갖고 있었으며, 진딧물 종류별 보독률은 복숭아혹진딧물 15.4%, 감자수염진딧물 9.1% 였다. 시기별로는 5월 하순부터 PLRV 보독 진딧물이 비래하였고 6월 중순에 비래한 진딧물의 바이러스 보독률이 10.4%로 가장 높게 나타났다. 고로쇠나무(Acer pictum subsp. mono (Maxim.)), 당단풍나무(Acer pseudosieboldianum (Pax)) 등 17종의 수목류에서 진딧물알이 월동하였다. 월동 진딧물은 복숭아혹진딧물(Myzus persicae), 홉사마귀진딧물(Phorodon humuli) 등 14종으로 동정되었다. 특히 자작나무진딧물(Betula platyphylla var. japonica), 단풍알락진딧물(Yamatocallis hirayamae) 등은 아직까지 감자에서 바이러스를 옮기는지 여부는 알려진 바 없지만, 넓 은 지역에 걸쳐 분포하는 기주식물에서 월동하기 때문에 앞으로 바이러스 매개 능력에 대한 연구가 필요하다.

Potato leafroll virus (PLRV) can be transmitted permanently to potato plants by only several species of aphids. Myzuz persicae (Sulzer) is well-known to having the highest transmitting capability of PLRV. In order to investigate the PLRV transmission of aphids migrated to highland area in 2018, aphids caught in the yellow water-pan trap were inoculated on the young leaf of indicator plant, Physalis floridana, and inspected by visually and ELISA after 2~4 weeks. As a result, 2.8% of the totally migrated aphids showed virus infected symptom on the indicator plant. PLRV transmission rate of M. persicae and Macrosiphum euphorbiae was 15.4% and 9.1%, respectively. Also, seven aphids out of 265 unidentified aphids showed PLRV symptom in the leaves. PLRV-borne aphids started to fly into the fields from late May, and the virus infection rate was highest of 10.4% in mid-June. M. persicae caught in mid-June showed higher infection rate of 46.7%, but unidentified aphid of 8.3%. Compared with past years, PLRV transmission rate in 2018 has slightly dropped.

The genus Diadegma is a well-known parasitoid group and some are known to have symbiotic virus so called polydnavirus (PDV, more specifically Ichnovirus, IV). The presence of the IV in the Diadegma species a has already been identified more than a decade ago. Previously we reported a DfIV, 62 genomic segments, 247kb from D. fenestrale which parasitized wide range of lepidopteran species (Generalist). However, DsIV from D. semiclausum which parasitized in the P. xylostella (Specialist) has 48 genomic segments, 208kb. Finally, 123 ORFs were re-annotated (repeat element protein, 41; cysteine motif protein, 11; viral innexin, 6; viral ankyrin, 8; polar residue rich protein, 7; N gene, 3; Neuromodulin protein, 2 and not assigned gene, 45). DsIV also have most of lepidopteran immunosuppression gene families and 103 ORFs annotated (repeat element protein, 36; cysteine motif protein, 8; viral innexin, 7; viral ankyrin, 6; polar residue rich protein, 7; N gene, 3; and not assigned gene, 36). Certainly, although viral species specific segments exists, two IVs showed high similarity in most of segments. However DfIV have some more number of that genes such as cysteine motif protein and viral ankyrin. Two Diadegma species also showed difference in mitochondrial genome structure. Therefore we concluded that two species has their own evolutionary linage depending on the lepidopteran hosts with its own symbiotic virus.

The world’s climate is changing. This can affect agricultural insects and the damage they cause by altering their ecology, behavior and habitats. Aphids are emerging as an indicator of climate change, and they are a good model for understanding these environmental changes, especially based on their migratory behavior. In this study, the occurrence of aphids in a seed potato field in Pyeongchang, Korea, was monitored daily using a yellow water pan trap from 1977 to 2017. During these 40 years, the annual migration fluctuations of the aphids were analyzed, with particular focus on four species known to vector potato viruses, Aphis gossypii, Aulacorthum solani, Macrosiphum euphorbiae, and Myzus persicae. It was found that, as time goes by, the start point of spring migration in these aphid species was getting earlier while the peak in autumn migration gradually moved to the winter season. Together with a mean annual temperature increase of 1.03 °C in Pyeongchang over the past four decades, there is a potential threat of expansion in the distribution of aphid species. that this temperature change could influence the aphid’s population changes in the Korean peninsula.

The cotton bollworm, Helicoverpa armigera is one of the most polyphagous and cosmopolitan pest species in world wide including Korea. It also showed high level of resistance against various types of insecticide. To set the integrated resistant management program, first, we tried to identify the insecticide resistant mechanism via transcriptome analysis of coding and non-coding RNAs using 4 strains (Australian susceptible and resistant strains, Korean and Brazilian resistant strains, additional a sub-lethal dose insecticide treatment in Korean resistant strain). From the illumina based RNAseq data sets with genome information, some resistant involved detoxification genes and long non-coding RNAs were discovered. Second, following molecular markers were developed from resistant strain specific amino acid substitution from those candidate genes. Third, functionally identified genes’ markers were applied in field populations using some molecular diagnostic tools such as LAMP (loop mediated isothermal amplification). Now additional functional analysis is going on for these un-characterized candidate genes and long non-coding RNAs.

The genus Diadegma is a well known parasitoid group in various lepidopteran insect such as Plutella xylostella andsome are known to have symbiotic virus. Previously we reported a novel ichnovirus as named Diadegma fenestrale Ichnovirus(DfIV, 62 segments, 247,238bp) from D. fenestrale which parasitized in the P. xylostella. Here we report another ichnovirus,DsIV from Taiwan strain of D. semiclausum which parasitized in the P. xylostella. Total 64 genomic segments were sequenced,185,053bp from DsIV. Two Ichnovirus showed high similarity in 99 regions in most of segments. We already confirmedintegration of DfIV genome segments into the chromosome from the P. xylostella via genome sequencing of the lepidopteranhost. Therefore some of recombination could be passible inside of the lepidopteran genome.

The world’s climate is changing. Aphids are emerging as lookouts of climate change and they are a good model to understand these environmental changes especially through migratory behavior. We monitored of the occurrence of aphid in same place (Pyeongchang) of seed potato field since 1977 in Korea. Dates of the start of spring migration of these aphids’ species were getting earlier. And, the pick of autumn migration were gradually move to winter season. Moreover, annual total numbers of collected aphids were also dramatically increased during 40 years. There is potential threats of distribution expansion of aphid species in Korea where is the hot spot of climate change with average temperature over 1.7 °C increase for 4 decades. Therefore we hypothesized that aphids’ migration pattern could be associated with temperature

Worldwide, increasing numbers insecticide resistant insect is one of the main problem in agriculture not only in the field but also in the storage. The rusty grain beetle, Cryptolestes ferrugineus is one of the cosmopolitan insect that infests a wide range of stored cereals and related commodities. Until quite recently, phosphine (PH3) has been effective in controlling this species in worldwide including Korea. However, strongly resistant populations of RGB have been detected in Australia that could threaten market access of infested commodities. Resistant populations detected in Australia showed extremely high levels of resistance to phosphine, up to 1300 folds higher than that of susceptible strain. So here we tried to identify their phosphine resistance mechanism based on transcriptome analysis using RNaseq in adult stage. Over 10Gb were sequenced in each strains and some of specific P450 were over expressed in resistance strain.

Increasing Lepidopteran pests such as Helicoverpa armigera are emerging pests of corn in Korea. They cause huge yield losses and deteriorate the quality of corn crop. We monitored the four major lepidopteran pests in major highland corn growing areas of Korea by employing sex pheromone trap during 2012 to 2015 for understanding those population dynamics. Among these species, H. armigera was found to be the main pest based on the damage intensity (80 ~ 90% of total damage). Some effective insecticides were selected such as Indoxacarb etc. Optimal timing of spraying was estimated at around 70 days after planting (earing season) to control H. armigera. Additional, two species of parasitoids (Therion circumflexum and Ophioninae sp.) was identified from H. armigera. However, more extensive survey for natural enemies is needed to set the natural enemy based control program.

The genus Diadegma is a well known parasitoid group and some are known to have symbiotic virus. A novel IV was discovered from the calyx of D. fenestrale female. This virus was named as D. fenestrale Ichnovirus (DfIV) and its genome contains 62 circular DNA segments with an aggregate size of approx. 240kb. We examined its gene expression patterns depending on the hosts (hymenopteran host, D. fenestrale and lepidopteran host, Plutella xylostella) and stages of P. xylostella based on RNAseq. Among 62 genome segments, only two segments such C15 and D14 were highly expressed in ovary of D. fenestrale. On the other hands, five segments were differently expressed depending on the developmental stages (3 rd and 4 th instar larvae). Additionally we confirmed integration of DfIV genome segments into the chromosome from the Plutella xylostella via genome sequencing of the lepidopteran host.

Increasing numbers of insecticide resistant insect is one of the main problem in current agriculture. To manage the insecticide resistance, IRAC suggest some tips for farmers : First, sequence or alteration of insecticide based on MOA. Second, choosing the effective insecticide. In this point raised following question : How to distinguish the effective or non-effective insecticide. Until now, bioassay is the right answer. However that is time-consuming, labor-intensive and costly process. So we have been steadily advancing molecular based insecticide resistance diagnosis for supporting and/or substitution of classical bioassay. It can summarized following steps : First, identification of insecticide resistance mechanism. Second, marker development. Third, development molecular diagnosis such as PASA, LAMP etc. Forth, application on field collected insects. Here we discuss some case of these study particular several major pests in highland agriculture.

Worldwide, increasing numbers insecticide resistant insect is one of the main problem in this agricultural era. To manage the insecticide resistance, IRAC suggest some tips for farmers : 1. Sequence or alteration of insecticide based on MOA 2. Choosing the effective insecticide. In this point raised following question : How to distinguish the effective or non-effective insecticide. Until now, bioassay is the right answer. However that is a very time-consuming, labor-intensive, and costly process, so we were hoping that molecular based diagnosis could be alternate. It can summarized following steps : 1. Identification of insecticide resistance mechanism 2. Marker development 3. Molecular diagnosis 4. Selection of non-effective insecticide. Here we focused on the development of insecticide resistance marker. Point mutation in target site of insecticide is a good example. Up or down-regulation of specific gene and/or existence of chimeric gene is another example from Helicoverpa armigera.

Potato Virus Y (PVY) (Potyviridae: potyvirus) is one of the serious emerging virus of seed potato world-wide. It affects the seed potato by transmitting non-persistently via aphids. Here, we developed a simple PVY detection method which used the boiling technique for releasing of the viral RNA from aphid such as stylet and amplification by PVY specific primers located in the viral coat protein gene which suitable for various strains. This simplified method could save the time compared to earlier detection method due to the simplified RNA extraction step. Following this procedure, we tested this one step RT-PCR based PVY detection method by using three PVY vectoring aphid species (M. persicae, A. gossypii and M. euphorbiae) as well as other sucking type insect such as thrips (F. occidentalis). This PVY detection method is rapid, easy-to-use and suitable for large-scale testing in laboratories of seed potato.

The habitat of the cockroach varies by species. The German cockroach (Blattella germanica) lives in human dwellings, while the Japanese field roach (Blattella nipponica) lives in a mountainous region. Based on phylogenetic analysis of mtCO I, the two species are closely related to each other and B. germanica is divergent from wild species such as B. nipponica. Their habitats and walking speed differ even though the two species have similar morphology. We hypothesized that habitats might influence walking speed via changes to appendage morphology and enzyme-based physiological differences. We found that phenotype such as appendage length and esterase isozyme expression were clearly different between the two species. These differences might be responsible for the observed difference in walking speed.

The striped fleas beetle (SFB), Phyllotreta striolata is a notorious and widely distributed pest in the world including Korea. We surveyed SFB insecticide resistance in Pyeongchang and Hoengseng population. Leaf dipping bioassay with recommended concentration of insecticides was performed using SFB adults. Two populations showed high level of resistance in various insecticides particularly neonicotinoids. Nicotinic acetylcholinesterase receptor (nAChR) is well known target site in neonicotinoid. Therefore, we tried to identify the nAChR from the SFB. Primary, partial contig sequence obtained by RNAseq from Hoengseng population and additional gap fillings were conducted. Total 12 nAChR subunits (10 alpha subunits and 2 beta subunits) were identified and phylogenetic relationships were predicted. Earlier studies reported that point mutations contribute to develop the imidacloprid resistance in aphids and brown planthopper, however we did not find it. Further studies relative to neonicotinoid insecticide resistance mechanism are demanded.

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.