Understanding biotic interactions is important to illustrate ecological functions of stream environments. The purposeof this study is to compare the ecological functions of natural and artificial streams. For linking species, we used bioticinteraction databases and made food-webs for species lists of 18 streams in Seoul, Korea. We conducted species removalanalysis of networks and compared network beta-diversity between watersheds. The results showed that natural streamswere more affected by a removal of keystone species than artificial streams. The cheonggye watershed including artificialstreams had high dissimilarities among streams, presenting that artificial streams had different functions from natural streams.

Yellow sticky traps are a key component of IPM programs for several greenhouse and vegetable pests. Yellow sticky traps have been used intensively for early detection, identification of hotspots as well as for estimating relative abundance and dispersals of adult insects occurring either in greenhouses or fields. In addition, the traps have the potential of suppressing adult populations alone or in combination with other control strategies such as biological and chemical controls. In spite of the fact that the traps have been widely used with several advantages for growers such as low cost and low training demands, the understanding of insect flight and dispersal behaviors based on sticky traps have been limited. Since the trap catches are highly associated with flight behaviors of insects, the catch data should be carefully interpreted and analyzed in conjunction with the flight behaviors of target insects to develop ecologically sound IPM programs. Thus, a control decision-making based on mean trap catches without knowledge in the flight behaviors may produce biased or wrong conclusion. In this study, flight and migration behaviors of insect pests such as thrips, whiteflies and leafminers are studied based on sticky trap catch data obtained from greenhouses and fields. Also I summarize the knowledge gaps that need to be addressed to develop yellow sticky traps into a more effective decision-making tool for pest management.

Recently, an integrated approach in insect ecology that including development of biological models and estimation of various effects using a logical model has become important. Through the biological components of ecosystem having complex temporal and spatial patterns, and complicated interactions of biotic and abiotic factors, dynamic models can be useful tools to investigate the whole ecosystems. Pollutants in terrestrial ecosystem can be transferred to insect body through insect’s sucking plant tissue, and effect on their biological properties. Trend of pollutants transfer from soil to plant root can be estimated using free ion activity model (FIAM), and distribution and accumulation in plant parts can be described by dynamic model with water potential, water translocation, and transfer rate. Biological response of plant and insect can be illustrated the dynamics model based on experiment data. The combination of these models show an overall behavior of toxicant and the interaction between plant and insect with time. The objectives of the research are to comprehensively analyze the transfer and effects of pollutant in soil, plant and insect system and to develop the assessment technique for soil ecosystem using dynamic modelling concerning the causal relationship and feedback processes. We are aimed specifically at prediction and assessment of various polluting scenarios of soil ecosystem through data collection from laboratory and field investigation, modelling and evaluation using module software programing.

Effects of environmental stressors such as pollutants and anthropogenic perturbance on the health of aquatic/terrestrial ecosystems usually involve a series of biological responses ranging from the biomarkers to the individual, population and community levels. Extrapolation is the use of existing information for the prediction of events in another situation that is biologically different from that where the existing information was gathered. To establish relationships and to determine the feasibility of extrapolating between higher and lower levels of biological organization, temporal or spatial patterns in organism responses to contaminant Invertebrates are widely regarded as powerful monitoring tools in environmental management because of their great abundance, diversity and functional importance, their sensitivity to perturbation, and the ease with which they can be sampled loading have been studied with various living organisms and ecosystems. By identifying and establishing relationships between levels of biological organization of invertebrates we should be better able to understand the mechanisms of stress responses in ecological systems that could ultimately result in improved predictive capability of ecological risk assessment and also allow for more informed decisions regarding remedial actions.

A new collembolan species (Paranura rosea) which was native to Korea was selected for evaluating the effect of temperature on their biology. Development, and reproduction of P. rosea were investigated at 15, 20, 25 and 30℃ Hatchability of egg was not affected by experimental temperature, and the lower threshold temperature for development of P. rosea was estimated to be 7.53℃. The temperature reduced the juvenile and adult (maturity period). The intrinsic rate of natural increase and finite rate of increase per week at 20℃ which are maximum values showed significant difference with other experimental temperatures. Survival rate, cumulative reproduction and head capsule width was fitted by several models. Especially, the model which fitted for estimating head capsule width was used to determine their life stage. Estimated head capsule width of P. rosea at the initial oviposition varied with temperature from 0.36 ± 0.007 to 0.45 ± 0.007 with maximum at 20℃ and minimum at 30℃, and significant difference was observed at all the experimental temperature (P<0.05). However, estimated head capsule width at the last oviposition showed different statistically result at only 30℃. Molting frequency per week of one P. rosea was increased as the temperature increased. Based on this study, temperature greatly influenced on their life stage and reproduction. Therefore, relationship between temperature and P. rosea is very important for understanding their biology.

충남부여에 위치한 임업화훼단지내의 유리온실에서 아치형재배(Arching method)장미에 피해를 주는 점박이응애(Tetranychus urticae Koch)의밀도를 엽당 응애수로 조사하였다. 이항표본 조사법은 엽당 점박이응애의 평균밀도(m)와 점박이응애가 T 개체보다 많이 존재하는 엽의 비율()과의 관계를 기본으로 하며, T는 경험적 이항분포모형(ln(m)=+1n(-1n(1-)))에서의 tally threshold 로서, 본 실험에서는 1, 3, 5, 7, 9를 사용하였다. 일반적으로 표본단위 수의증가는 T와 상관없이 이항분포 모형의 정확도에 영향을 거의 주지 않게 된다. 본 실험에서는 상이한 T에 따라 이항분포모형의 정확도가 차이가 났으며 T가 증가할수록 정확도가 높아졌다. 본 실험결과 점박이응애의 밀도추정을 위한 이항분포모형의 정확도를 비교한 결과, T=7인 경우가 최적의 tally threshold인 것으로 나타났다. 또한 이항분포조사법의 검정을 위하여, 동일한 포장의 독립적인 표본을 추출, 조사하였다. 본 실험결과 이항표본조사법을 이용한 상업적 유리온실의 아치형재배 장미해충인 점박이응애 평균밀도 추정에는 T=7인 경우가 가장 적절한 것으로 사료된다.