Aquatic oligochaetes were investigated from a small amount of sediment sampled from the Jung-nang Stream, an urban stream in Seoul, Korea, in November 2012. Sorted oligochaetes were observed under alight microscope in a drop of carbonated water, and then preserved in 70% ethanol. Some specimens were slidemounted using glycerin and Eupharal. As a result, the following 12 species were identified including 8 newKorean records, Bothrioneurum vejdoskyanumStolc, Branchiodrilus hortensis(Stephenson), ChaetogastercristalinusVejdosky, Nais communisPiguet, Nais pardalisPiguet, Dero obtusad’Udekem, PiguetielladenticulataLiang, and Haemonais waldvogeli Brescher and 4 additional known species, Limnodrilus hoffmeisteriCleparéde, Branchiura sowerbyi Beddard, Chaetogaster diastrophus(Gruithuisen), and Stylaria fossularisLeidy.This study shows how freshwater oligochaetes are diverse even in urban streams in Korea, if a propersamplingand examining method is employed.
The caddisfly family Hydropsychidae, containing about 1,500 described species is the 3rd largest family in Trichoptera. They are among the important components of biomonitoring programs because of their abundance and wide range of pollution tolerance values among species. In tropical Southeast Asia, 12 genera were currently recognized belonging to three subfamilies: Diplectroninae, Macronematinae, and Hydropsychinae. Herein, updated checklist and distribution of tropical Southeast Asian Hydropsychidae species were provided based on the review of published literatures and the trichoptera world website.
As a result, a total of 356 species of tropical Southeast Asian Hydropsychidae have been described wherein the four most abundant genera were Hydropsyche (116 species), Cheumatopsyche (91 species), Diplectrona (42 species), and Hydromanicus (35 species).
Tropical Southeast Asian Trichoptera studies were mostly done in Vietnam, Thailand, Indonesia, and in the Philippines making some other tropical Southeast Asian countries unexplored.
Cave-dwelling springtail studies in Korea initiated during 1960s by the Japanese Collembola researcher, R. Yosii, and comprehensive taxonomic studies on Korean Collembola were conducted by B. H. Lee during 1970-1990s wherein the new family Gulgastruridae was established using the type species Gulgastrura reticulosa from the Gossidonggul cave in Gangwon-do, South Korea. Eight families of cave-dwelling Collembola are known in Korea, and the family Tomoceridae is the most abundant and diverse group of cave-dwelling Collembola with 11 known species belonging to 4 genera in Korea. In this study, 12 species of Korean Tomoceridae are reviewed, and 1 new species from the genus Plutomurus and 2 new species from the genus Tomocerus are described.
연못하루살이의 성장에 필요한 유효적산온도를 구하고 자 2011년 8월 7일부터 10월 10일까지 야외에 설치한 실 험 수조에서 실험을 수행하였다. 실험 수조 설치일로부터 4일 경과 후 수면에서 죽은 암컷 성충 한 개체가 발견되 어 산란이 이루어졌을 것으로 추정하였으며, 산란추정일 로부터 39일째부터 성충이 우화하기 시작하여 61일째에 마지막 개체가 우화하였다. 우화한 성충은 총 229개체였 고, 성비(암컷 수/전체 수)는 0.45로 수컷이 많았으나 통 계적으로 유의하지 않았으며(p¤0.05), 전체적으로 수컷 이 먼저 우화하는 경향을 보였다. 최저 발육임계온도를 0C로 하여 유효적산온도를 산출한 값은 1,221.8±116.0 DD였으며, 대조습지의 연간 유효적산온도가 5,650.0 DD 임을 고려할 때, 연못하루살이는 본 연구결과를 적용할 경우 야외 서식처에서 최대 1년 4세대의 생활사를 가질 가능성이 있다.
Members of the non-biting midge family Chironomidae are the most widespread and abundant group of aquatic insects in fresh waters. Although the composition of chironomid communities is considered to be a potential biotic index for water quality assessment, it has not been used easily because of the difficulties with species level identification for larvae. This study was to analyse the molecular operational taxonomic units (MOTU) in chironomid communities to appropriately apply a species level identification. A total of 41 chironomid larvae collected from 7 sampling sites in the Han river system according to water quality were used for analyses. Partial mitochondrial DNA cytochrome c oxidase I (COI) genes were sequenced and analyzed. As a result, 35 different haplotypes (MOTU01-13) were obtained from the 673bp COI sequences. Average genetic distance was 0.0041 (range 0.000 to 0.013) within the MOTU and was 0.1703 (range 0.1181 to 0.2456) between the MOTUs. Nine MOTUs were found at the stream sites represented water quality A, 2 MOTUs at water quality C, and 1 MOTU at water quality D.
Pesticide application pattern for agricultural insect pest was modeled and simulated by temperature change scenarios using DYMEX simulator. For modeling pesticide application pattern, we evaluated bioassay using two-spotted spider mites (TSSM) in vitro. Four separated bioassay was evaluated at four different temperature conditions (20, 25, 30, and 35℃). Selected four commercial pesticides were Acrinathrin-Spiromesifen mixture, Fenpropathrin, Abamectin, and Azocyclotin, respectively. All the pesticide was used its recommended dose, except Abamectin (1/10 of recommended dose). Each mortality of TSSM were counted after 24 and 48 hours.
Based on the bioassay results, increasing temperature made decreasing mortality in Acrinathrin-Spiromesifen mixture and Fenpropathrin, whereas increasing mortality in Abamectin and Azocyclotin, respectively. A TSSM model was developed and simulated under four temperature increasing scenarios (present condition, average 1, 2, and 3℃ increased conditions) using DYMEX simulator. The DYMEX results showed that the pesticides application pattern were different among four pesticides under climate change scenario. In conclusion, the pesticide application should be changed for sound management of agricultural insect pest under climate change scenario.
Korean species of the dragonfly family Gomphidae are reviewed based on a comprehensive specimen examination. The family can be easily recognized by separated compound eyes, yellowish body color, and similar features of triangle cells on fore- and hindwings. Since a report of 4 Korean species (Seiboldius japonicus, Gomphus melampus, G. postocularis, Gomphus sp.) of the family by Doi (1932), 18 species belonging to 13 genera were recorded by Lee (2006). In this study, we added 5 species and reviewed 23 species of Korean Gomphidae. Identification key and taxonomic remarks were provide: Asiagomphus pryeri is recorded for the first time in South Korea; 3 North Korean species in the genus Davidius are added; Gomphus postocularis is treated as subspecies Shaogomphus postocularis epophthalmus; larval stage of Burmagomphus KUa is identified as Burmagomphus collaris; Ophiogomphus forficula is the synonym of O. obscurus not O. reductus.
Traditionally oxygen demands and concentrations of variable pollutant have been used for the assessment of lentic or lotic water quality. But there is a high probability that newly synthesized chemicals flow into the aquatic ecosystem, and it is very hard to investigate that many kinds of chemicals interact even though they exit at lower level than legal standards. As a consequence of limitation of chemical assessment for media, biological assessment techniques for accepters which are affected by pollutants or physicochemical properties have been developed. However, it still has several weak points because it does not have the ecological relevances using the internationally standard test species which do not inhabit Korea. Besides, the assessment using just one or two species may have a possibility of overestimation or underestimation because a certain species can be extremely sensitive or insensitive to a certain chemical or physicochemical property. Therefore, we used four kinds of indigenous aquatic invertebrates to assess the local stream quality and integrated their responses into a new index which ranges from 0(bad) to 1(good). We assessed four streams throughout Ansan and one stream in Gapyeong, and index values of two streams near residential and industrial area in Ansan were under 0.9 and the others were over 0.9.