꿀벌류은 화분매개에 있어 중요한 곤충이다. 최근 농업환경에 노출되는 합성 작물보호제에 의한 꿀벌 독성에 관한 우려가 높아지고 있다. 본 연구는 네오니코티노이드계 살충제의 급성 섭식 독성이 꿀벌 체구에 따라 달라지는지를 평가하였다. 실험 봉군은 태국 치앙마이대학에서 유지하고 있는 것과 일부는 인근에서 채집하여 사용하였다. 일벌 성충의 체구 크기 순은 다음과 같다: Apis florea, A. cerena, A. mellifera, A. dorsata. 처리 약제는 네오니코티노이드계 3종; Thiamethoxam, Imidacloprid, Clothianidin과 카바메이트계 Carbaryl이었다. 추천 농도에서 10배부터 100,000배까지 6단계로 농도 구배를 두고, 섭식 처리하였다. 사망의 판정은 붓으로 건드렸을 때 2회 연속 움직이지 않을 때를 사망으로 처리하였다. 대부분의 경우, 개체 평가와 집단 평가에서 차이가 없었다. 사망률은 농도에 따른 반응을 보였다. 반수치사농도를 기준으로 볼 때, 4종 약제의 독성은 체구가 작은 A. florea가 대체로 가장 낮게 나타났으며, 체구가 가장 큰 A. dorsata가 가장 높게 나타났다. A. cerana는 Thiametoxam에 특히 민감한 것으로 나타났고, A. florea의 Imidacloprid에 대한 반수치사농도가 특이하게 높게 나타났다. LT값은 처리 농도에 따른 전형적인 반응을 보였다.
In our previous study with sequenced data from DNA barcoding region of Korean Tettigonia showed that the Jeju population of T. ussuriana (JJ-Tu) more closely related to T. dolichoptera than mainland population of T. ussuriana (ML-Tu) with low genetic distance (0.87-1.05%). In mitochondrial systematics for a eukaryotic organism including orthopteran insects, sequence data from a short mitochondrial DNA fragment should be trait with caution because nuclear mitochondrial pseudogenes (numts) can be unintentionally coamplified when we use universal primers based on a PCR method. In this study, we retried their sequence analysis to avoid coamplication of numts in sequences from cox1 and cox2 genes. and scrutinized each sequence. The molecular evidences (cox1, cox2, and nad1) for Korean species suggest that JJ-Tu is more closely related to T. dolichoptera (0.76-1.23% in cox1; 1.23-1.54% in cox2; 1.01-1.35% in nad1) than ML-Tu (3.77-4.59% in cox1; 3.61-4.76% in cox2; 2.03-3.25 in nad1). The genetic distance of sequence data from cox1 between JJ-Tu and ML-Tu satisfied a requirement for species-distinction by comparing genetic distance between Tettigonia species. Moreover, JJ-Tu is a geographic population of Tettigonia with different morphological traits that is supported with formed a cluster. Although JJ-Tu closely related to T. dolichoptera with low genetic distance, we will determine its taxonomic status through integrative taxonomic study.
꿀벌(honey bee)은 대표적인 화분매개곤충으로 산업적 가치가 높을 뿐만 아니라 생태계에서도 중요한 위치를 차지한다. 2006년 이후 꿀벌군집붕괴현상(CCD)으로 인해 수많은 꿀벌들이 죽었지만 아직까지 그 정확한 원인이 밝혀지지 않아 여전히 꿀벌들의 생존을 위협하고 있다. 이와 더불어 최근 기후변화에 의한 불확실한 환경조건 또한 꿀벌을 위협하는 요소들 중 하나이다. 본 실험에서는 이러한 외부 환경 조건에 대한 꿀벌의 생리적인 반응을 측정하기 위해서 heat shock protein (hsp) 유전자를 이용하였다. 꿀벌의 유전체 분석을 통하여 36개의 hsp 유전자를 선발하였다. 이들 중 hsp40, hsp70, grp78, hsp90를 선정하여 quantitative real-time PCR를 통해 발현량을 분석하였다. 고온 처리(40, 45, 50°C)를 했을 때 45°C에서 hsp 발현량이 가장 높았다. 그리고 조직별(지방체, 중장, 날개 근육)로는 날개근육에서 발현량이 가장 높았다. 적화제 섭식 시 hsp 발현량이 증가하였지만, 살충제 이미다클로프리드 섭식 시는 hsp 발현량이 감소하였다. 즉, 외부 스트레스에 대해 꿀벌 hsp 유전자들의 발현이 다양한 패턴을 나타냈다. 이를 바탕으로 스트레스에 반응하는 꿀벌의 생리에 대해 더 폭넓은 이해가 있을 것으로 예상된다.
The repellent activities of 33 plant extracts against Aedes albopictus were examined using a patch test for adult. The six plant extracts (Magnolia denudate, Dryopteris crassirhizoma, Cnidium officinale, Lindera obtusiloba, Magnolia kobus, and Houttuynia cordata) showed over 70% repellency activities to Ae. albopictus. The insecticidal activity of Curcuma longa against Ae. albopictus was also determined. C. longa hexane extraction showed 100% larvicidal activity at 1,000 ppm after treated 24 h. Purification of the biologically active constituents from the hexane extraction with larvicidal activity was done using silica gel column chromatography. H1 fraction gave 100% mortality to Ae. albopictus at 100 ppm. H12 fraction was determined 87.8% larvicidal activity to Ae. albopictus at 50 ppm. Active constituent was analysed as the sesquiterpene, ar-turmerone (C15H20O) by GC and GC-MS. C. longa extract gave highly protection against mosquito bites. The hexane extraction showed complete protection at 10 mg over 6 h. In this study, the sesquiterpene from C. longa induced a protection time, repellency, landing time, and biting time against Ae. albopictus.
These results suggest that the some plant extracts and C. longa have the potential to be used an eco-friendly materials for the control of mosquitoes.
Vollenhovia emeryi (Hymenoptera: Myrmicinae) is dimorphic in its wing morphology of alate females: the long-winged and the short-winged. In our previous study, we found that the long-winged is ancestral and the short-winged is derived. Intriguingly, the former is infected with the intracellular symbiotic Wolbachia bacterium and the derived is void of the bacterium indicating that the latter somehow evolved resistance to the bacterium.
This may be one of few cases in which transition from susceptibility to the bacterium can be traceable via the divergence estimation. As a consequence, we inferred that the two morphs diverged approximately quarter million years ago; a remarkably recent event in evolutionary perspective.
In this presentation, we will further discuss genetic orchestration in the host insect and future research directions.
An oxidative fumigant is potent to kill insect pests infesting stored grains. Its oxidative activity generates reactive oxygen species (ROS), which has been considered to be a main insecticidal factor. Furthermore, the oxidative fumigant has cytotoxic effect to insect cell lines, but the cytotoxicity is abrogated by antioxidant treatment. This study aimed to extend the usefulness of the oxidative fumigant in terms of medical purpose against cancer cells. Five cancer cell lines HCT 116 (human colorectal), Lovo (human colorectal), SW480 (human colorectal), MDA-MB-231 (human breast), and MCF-7 (human breast) were tested to determine their susceptibility to the oxidative fumigant with reference to two insect cell lines (Sf9 and Hi-Five). All cancer cell lines were highly susceptible to the oxidative fumigant, compared to the insect cell lines. Interestingly, basal ROS levels of the cancer cell lines were much higher than the insect cell lines. Furthermore, the oxidative fumigant significantly increased the ROS levels in the cancer cells. Treatment of vitamin E as an antioxidant mitigated the cytotoxicity of the oxidative fumigant. Thus, the high susceptibility of cancer cells to the oxidative fumigant may be induced by their high inducible ROS production. This study also investigated the antiviral activity of the oxidative fumigant against insect and plant viruses. The oxidative fumigant significantly inactivated a baculovirus (dsDNA virus) by inhibiting polyhedral production in Sf9 cells. It also inactivated tobacco mosaic virus (ssRNA virus) by suppressing phytopathogenicity. These results support a broad effect of the oxidative fumigant, which can be applied to agricultural and medical purposes.
The sweetpotato whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is a disastrous pest in horticultural plants worldwide. B. tabaci is a species complex including at least 24 biotypes in the world. In Korea, B-biotype has been invaded in 1998, Q-biotype in 2005 and widely spread into the country. B. tabaci is also a vector of more than 100 plant viruses, especially begomoviruses. Since 2008, Tomato yellow leaf curl virus (TYLCV) has been invaded into Korea and severely damaged tomato cultivar in all over of the country. B. tabaci is the only vector insect of TYLCV. Here we demonstrated whether TYLCV influence on the vector physiology during virus transmission. Pesticide susceptibility of whiteflies on TYLCV acquisition was determined in B. tabaci using the two-layered parafilm feeding chamber which containing 20% sugar solution including different doses of imidacloprid. Our result showed that TYLCV-viruliferous whiteflies were more susceptible to imidacloprid ingestion than non-viruliferous whiteflies. This study suggests that plant virus can manipulate the physiological conditions of vector insects.
이온화에너지 조사는 수확후관리와 더불어 검역해충을 방제하는데 유용한 기술이다. 본 실험에서는 다양한 과수 작물에 피해를 끼치는 검역해충인 벚나무응애(Amphitetranychus viennensis Zacher)에 대한 이온화에너지 조사 효과를 조사하였다. 벚나무잎에 사육한 벚나무응애 암컷 성충(n=100/처리구)을 이용하여 감마선 (0-1000 Gy), 전자빔과 X-선 (0-1500 Gy)을 조사하였다. 벚나무응애의 생존율, 부화율, 산란율은 각 이온화에너지 처리에 따라서 차이가 나타났으며 감마선 및 X-선의 효과가 전자빔보다 높게 나타났다. 그러나 벚나무응애 성충의 생존율은 감마선 1000 Gy 처리시 18.3%, X-선 1200 Gy 처리시 10.0%로 나타났다. 이온화에너지 조사를 통하여 식물검역과정에서 벚나무응애의 소독에 적용할 수 있을 것으로 판단된다.
일본흰개미 아종(R. speratus kyushuensis)에 의한 목조문화재 손상은 제주도 및 울릉도를 포함한 한반도 전역에서 발생하고 있으며, 지구온난화 등과 맞물려 피해가 심화되고 있다. 기존의 흰개미 군체제거제는 주로 생장조절제를 이용하여 방제 기간동안 목조문화재의 추가적인 손상이 우려되었다. 이에 효율적인 흰개미 군체 제거를 위해 페닐피라졸계 약제 피프로닐의 흰개미 군체제거약제 적용성 연구를 수행하였다.
섭식독성평가 결과 공시충들은 1~1,000ppm(w/w)의 피프로닐 처리 독먹이에 대해 비기피성을 나타냈으며, 1~10ppm(w/w)의 저농도에서 LT50은 4.43~4.99일이며 9일이 경과할 때까지 일부 공시충이 생존하여 지효성 살충효력이 나타났다. 실내 군체제거력 평가 결과 공시충들은 10ppm(w/w) 피프로닐과 Nile Blue A 0.1%(w/w) 염색약을 처리한 독먹이를 활발히 섭식하여 4일 경과 후 체색이 푸르게 변한 공시충들이 육안으로 관찰되었다. 13일 경과 후 일부 공시충 사체가 토양 중에 축적되었으며 21일 경과 후 모든 공시충이 사멸하여 군체제거 효력이 나타났다. 현장적용성 평가 결과 10ppm( w/w) 피프로닐 독먹이 섭식 4주 후 야외 흰개미 군체의 활성이 저감되었다. 평가 결과를 통해 저농도 피프로닐은 기존 생장조절제보다 효율적인 흰개미 군체제거제로 활용할 수 있을 것으로 추정되었다.
Genus Tautoneura Anufriev, 1969 (Hemiptera: Auchenorrhyncha: Cicadellidae: Typlocybinae) were recorded 59 species in the world. Among them, only 1 species: Tautoneura mori has been recorded so far in the Korean Peninsula. Tautoneura mori is known as a major pest of Mulberry in China and Japan, and we also confirmed that it appears on Mulberry in Korea. In this talk, we confirmed two new records: Tautoneura japonica, Tautoneura tricolor to the Korean typhlocybinae fauna, and we also discovered one new species to science. Additionally, we provide biological information such as host plants and distributional records, with a key to the Korean Tautoneura species. We also discuss potential status of each species as an agricultural pest concerning its biological traits.
To identify the key effects of human disturbance on terrestrial ecosystems is a major issue in the contemporary conservation. We compared the community structure of ground beetles among different forest patch sizes according to the different forest types. In addition, we examined how different functional groups and species responded to patch size, and habitat and geographical variables. We sampled ground beetles in 9 continuous forests and 18 patches including 6 deciduous, 6 Korean pine, and 6 Japanese red pine. Ground beetles were collected using 5 pitfall traps in each site, and replaced every month during May to October in 2013. Individual-based rarefaction curves indicated that higher species richness was found in continuous forests than forest patches irrespective of the forest types. Positive relationships were found between forest patch size and species richness of each functional group associated with forest habitat. When all patch size, geographical, and habitat variables were considered simultaneously for multiple regressions, patch size, longitude, latitude, elevation, organic matter, and litter depth were generally selected as significant predictor variables of the abundance and species richness of forest specialists, brachypterous, dimorphic, and large-bodied species, although longitude was only selected as a best predictor for 27 study sites in MRT. In conclusion, decreasing patch size is a major factor to the loss of biodiversity for ground beetles. To reduce biodiversity loss caused by habitat fragmentation, therefore, protecting as large as old-growth forests and improving habitat quality are critical for the biodiversity conservation and enhancement.
Cotton aphid infests more than 700 plants and a major pest of various horticultural crops worldwide. The glucose regulated protein 78 (GRP78) is a member of heat shock protein 70. Its expression is associated with the nutritional changes as well as environmental stresses. The full sequences of grp78 cDNA of Aphis gossypii was determined. It had conserved motifs of hsp genes and terminated in KDEL which is common to GRP78. Quantitative realtime PCR showed that its level was changed during development and also upregulated by starvation. However, its level was not much changed by heat stress. The level of grp78 can be use to understand nutritional physiology on insects.
Both juvenile and adult nutritional environment (e.g. macronutrient composition) can alter developmental trajectories, independently or interactively, to shape behaviour in later life. Moreover, variation in macronutrient composition across life stages can lead to among-individual covariation between behaviours (‘behavioural syndromes’) as well as among-individual variation in single behaviours (‘personality’). In this study, we used field crickets Gryllus bimaculatus and a split-brood experimental design to compare the expression of behaviours, their among- and within-individual variances across nutritional conditions. We showed that effect of macronutrient compositions on the mean level of behaviour was generally associated with the change in variance components in the behaviour. However, sometimes variance components in behaviours changed independently from the diet effect on mean level. Interestingly, we also found that diet effect on behavioural syndromes could be independent from diet effect on the mean level of behaviour and its variance components. As a consequence, we suggest that nutritional condition can assert a direct influence on the covariation between behaviours. This implies that expressions of genes with pleiotropic effects differ in their directions between nutritional environments.
Two species of the subgenus Exosyntretus (Hymenoptera: Braconidae: Euphorinae) in the genus Syntretus are reported from Korea in this study. The species of the genus Syntretus are small parasitic wasps, which attack adult Hymenoptera. Their hosts are adult parasitoid wasps and adult bees. The subgenus Exosyntretus are known as only five species in the world. Among them, Syntretus (Exosyntretus) nevelskoii Belokobylskij is new to Korea. The world checklist, diagnosis and distribution data are included.
Two species of the genus Cosmophorus (Hymenoptera: Braconidae) are reported in this study. Members of Cosmophorus are known as solitary koinobiont endoparasitoids of adults of barkboring and woodboring Scolytidae. The genus Cosmophorus of the subfamily Euphorinae is small in the size and enigmatic in the ecology, which has been recorded in Holarctic, Oriental, Afrotropical and Australian regions. Only five species are known in East Palaearctic. Among them, Cosmophorus (Cosmophorus) klugii Ratzeburg is new to Korea. Diagnosis and distribution data are included.
Two species of the genus Asiacentistes (Hymenoptera: Braconidae) are reported in this study. The genus Asiacentistes is a small braconid group distributed in the East Palaearctic and Oriental regions, which has only two species in the world. One of them, Asiacentistes sinica Chen and Belokobylskij is new to Korea. Diagnosis and distribution in East Asia data are included.
Distribution and abundance of species are influenced by their environmental condition. Among various environmental factors, a vegetation is one of the most influential factors, because it is used as habitats as well as food resources. Arthropods including insects play a important role in forest ecosystems as grazers, scavenger, predators, etc. Deciduous and coniferous forests have different plant community composition, resulting in different environmental condition. In this study, we collected arthropod communities at two different deciduous and coniferous forest stands in the Mountain Gariwang. At each stand, three different sampling methods were used: soil core for soil macroinvertebrate, pitfall trap for wandering insects, and sweeping net for insects in the shrups. Therefore, sampling was conducted at vertical habitats in the forest. The results showed that there were no difference in the number of orders from soil at both coniferous and deciduous stands. However, the abundance was higher at coniferous stand than at deciduous stand. Collembola was the dominant taxa in soil. Meanwhile, there were no statistically significant differences of community composition between coniferous stand and deciduous stands. Multivariate analyses was conducted to characterize differences of communities at different stands as well as vertical distribution in forest.
본 연구는 소백산 산림지역을 중심으로 고도별 산림곤충의 분포에 대한 모니터링을 실시하였다. 대상 곤충종은 개미류, 보행성딱정벌레류, 나방류 대상으로 조사를 실시하였다.
2014년 6월부터 9월까지 총 3회에 걸쳐 혼효림 지역에서 해발 600m, 900m, 1,200m 각 지점에 10m×10m의 격자를 3개씩 선정하여 핏폴트랩(Pitfall trap)을 9개씩 총 27개를 설치하였다. 버킷식유아등트랩(Bucket trap)은 고도별 한 개씩 설치하였고, 타이머를 부착하여 PM08:00∼익일 AM02:00로 유아등 시간을 동일하게 설정하여 조사하였다.
조사결과 개미류는 총 3아과 15속 18종 9,221개체가 채집되었고, 주요 우점종으로 Pheidole fervida, Nylanderia flavipes 등의 분포가 확인되었다. 딱정벌레류는 총 2과 15속 20종 393개체가 채집되었고, 주요 우점종은 Synuchus nitidus, Aulonocarabus semiopacus 등의 분포가 확인되었다. 나방류의 조사는 총 15과 168속 199종 2,151개체가 채집되었으며, 주요 우점종으로 Alcis angulifera, Herpetogramma fuscescens 등 다양한 분류군이 채집되어 기본적인 정보를 분석하는데 중요한 자료가 될 것으로 판단된다.
조사된 곤충류 중 국립수목원 (2011)에서 선정한 북방계곤충(463종), 남방계곤충(284종)에서 Lasius hayashi를 포함하여 23종의 취약곤충종의 분포가 확인되었다.
Intermediate disturbance hypothesis is one of important hypotheses for presenting the diversity patterns under disturbances. To investigate the diversity patterns of benthic macroinvertebrate communities under various disturbances, we collected macroinvertebrates in 47 sites representing various habitat types as well as pollution gradients in Southeastern Korea in summer and winter. Environmental variables such as depth, velocity, substrate and conductivity, and biological water quality indices (e.g., BWMP) were measured to show the intensity of disturbance in each site. Species abundance distributions (SADs) which are one of the efficient ways to assess community structure states based on macroecology were also considered to represent the pollution status based on the community patterns along an established pollution gradient. The community patterns were broadly divided into log-normal distribution and geometric series groups according to SAD models with weak and strong disturbance, respectively. According to the application of physicochemical water quality variable (conductivity), the gradient of community indices showed higher values on the intermediate disturbance state. Higher values of community indices, however, were presented on the low disturbance state with the gradient from BMWP. The parameters of SAD models, log-normal distribution, γ, and geometric series, k, were additionally calculated and compared with the traditional community indices.
Benthic macroinvertebrates are sedentary and have an intermediate life span ranging from months to a few years. They play a key role as consumers in the food trophic structure by linking producers, top carnivores, and decomposers in aquatic communities. Therefore, they have been widely used for ecological assessment of aquatic ecosystem health in an integrative and continuous manner. In this study, we characterized benthic macroinvertebrate communities at reference sites, which are not disturbed. Benthic macroinvertebrates were collected seasonally with a Surber net at three different streams (Pocheon, Hongcheon, and Namhae). In addition, hydrological and physicochemical environmental factors including temperature, discharge, width, conductivity, dissolved oxygen and pH were also measured at each sampling site. Spatial and temporal differences of benthic macrointertebrate communities were analyzed based on community indices, functional guilds, etc. relating to their environmental factors. Multivariate analysis were used to characterize the relationships between communities and environmental factors. Benthic macroinvertebrates were significantly different among sampling sites reflecting differences of their environmental condition such as hydromorphological factors, meteorological factors, etc.