Hea-Son Bang

Ovipositional Characteristics of the Ussur Brown Katydid, Paratlanticus ussuriensis (Orthoptera: Tettigoniidae)

Paratlanticus ussuriensis oviposited from early July to mid-September under laboratory condition. A female laid on average 145 eggs during the period of reproduction and over 54% of the eggs were laid within 2 weeks after the first laying. The average depth of egg-laying in soil was 19.4 mm under surface. The average major axis of an egg was 5.7 mm and the minor axis was 2.0 mm. Just before hatching, the egg swelled about twice the weight of a newly laid. In tests of ovipositional preference in different types of media, more eggs were laid in soil than in vermiculite or in Oasis ® floral form. Females also prefer shaded places in the field for reproduction, away from sunshine. In terms of the strategy for egg survival, adult moves to the hill-side adjacent to orchard farm to find a proper place for their egg laying and its survival in winter.

Effects of Chilling and Overwintering Temperature Conditions on the Termination of Egg Diapause of the Ussur Brown Katydid Paratlanticus ussuriensis

Temperature effects on diapause termination of Paratlanticus ussuriensis eggs were studied by measuring embryonic development and hatching rates at various conditions of indoor chilling and overwintering temperatures. Diapausing eggs of P. ussuriensis did not hatch at continued incubation at and even after chilling for once at either or for 30, 45 and 60 days. In addition, double chillings at with a 90 days interval at did not induce hatching of diapausing eggs. However, double chillings at induced hatching at 3.626.7%. When eggs were incubated at after chilling for once at for various periods, those weights were not changed but those chilled at gradually increased to approximately 1.5 times. When 60-days-old eggs were artificially deposited under the soil at three different mountain sites in September 2007, the hatching rates of the first-overwintered eggs were 11.3, 3.5 and 4.1% and those of the second-overwintered eggs were 25.1, 21.6 and 0.4% at Hoepori, Bitanri and Hwasanri, respectively. Most eggs were hatched from mid-March to mid-April but little bit earlier in southern regions. During the hatching period soil temperatures in three tested locations were around 8 to . In overall, diapausing eggs of P. ussuriensis were greatly influenced by chilling temperature conditions and those repeated cycles, and may required overwintering for one or two times to hatch for the post-embryonic development.

The Fauna of Aquatic Invertebrates in Paddy Field

지속가능한 농업과 안전한 쌀을 생산하기 위해서는 건전 하고 균형있는 농업생태계 보전의 필요성이 대두되고 있다. 특히 환경보전에 대한 국민의 관심과 건전한 농업환경에서 , 생산된 안전농산물의 선호도가 증대됨으로서 농산물 생산지 환경의 중요성이 날로 높아지고 있다 논에 서식하는 생물들은 . 환경변화에 민감하게 반응하여 농업생태계의 건전성을 평가 하는 기준이 되고 있다. 최근 생물다양성은 국가 간의 자원경쟁과 맞물려 국가의 주권으로 인식되고 있으며 이에 따라 세계 각 국은 생물다양 , 성 유지를 위한 많은 전략들을 구상하고 있다 다양한 서식생 . 물들로 이루어진 농업생태계에서 논에 서식하는 수서무척추 동물은 논 생태계를 유지하는데 매우 중요한 지위를 차지하고 있다 하지만 천년 동안 논 생태계가 유지 관리되어 왔음에도 . , 5 ・ 불구하고 논 생태계에 서식하는 수서무척추동물에 대한 연구 는 미미한 실정이었다. 본 연구에서는 년간 논에서 채집된 표본을 토대 10 (‘97-’06) 로 수서무척추동물 약 종류를 정리하여 원색도감으로 발 222 간하였고 한민수 문 강 과 종이 논 생태계에 ( , 2006), 5 7 72 222 분포함을 보고하고자 한다.

Response of Ussur Brown Katydid, Paratlanticus ussuriensis to Light-Emitting Diodes(LED)

This study was conducted to determine the phototactic response of Paratlanticus ussuriensis to different wavelength of light by the use of LEDs and to provide a basic information for developing an improved trap with the longer trapping efficiency to control environment-friendly this katydid. P. ussuriensis were attracted to the single LED light source, especially, blue and white. For the multiple LED light sources, the movement of P. ussuriensis was not significantly different among LED-light bands. Overall, P. ussuriensis had a tendency to move to light source although they were not attracted to a specific wavelength of light. These methods may be used as information for conducting a phototactic response of other insects.

Geographical Distribution of Diving Beetles (Dytiscidae) in Korean Paddy Ecosystem

BACKGROUND: The paddy ecosystem is periodically disturbed with a relatively consistent cycle in short term. However, in long term aspect, the paddy as habitats of organisms has been affected by the change in farming practices. Accordingly, the composition and their densities of fauna species inhabiting the wet paddy has been changed. The geological distribution of a species is very helpful to understand the past and current status of habitats and biodiversity. METHODS AND RESULTS: We monitored 290 sites of open plain paddy or terraced valley paddy located in 138 cities or counties of South Korea and analyzed examine geological distribution of a taxon of freshwater invertebrates, diving beetles (Dytiscidae) which inhabited the paddy ecosystem. This survey was conducted from 2005 through 2007. The total species of diving beetles found in the paddy were identified to be 15 genus 26 species among the family of Dytiscidae. Among them, 24 species were found in the terraced valleys-in paddy fields, and 19 species were found in the open plain paddy fields. Eleven species of them were rarely found in the paddy. The average body size of the adult diving beetles of each species was between 2.0 and 35.0 mm. Most of the diving beetle species except for 11 species with rare frequency of occurrence were found in almost all sites of the terraced valley paddy fields but three species (Agabus browni, Agabus japnicus, and Ilybius apicalis) were not found in the open plain paddy fields. The species distributed relatively widely over some sites of the open plain paddy fields were Guignotus japonicus, and Rhantus pulverosus. Specifically, Ilybius apicalis was found in a specific region, the east-southern part of Korean peninsula, whereas Coelambus chinensis was found only in valley paddy field of the region where Ilybius apicalis was not found. Overall distribution range of diving beetles in open plain paddy fields was limited to few area than in terraced valley paddy fields. CONCLUSION(s): The differences in the range of distribution of diving beetles between terraced valley paddy fields and open plain paddy fields was thought to be the result of an complex action of physico-chemical environments such as annual water status and the degree of chemical application involving differences in the extent of disturbance of the paddy ecosystem, the connectivity of the paddy to an adjacent biotope, and interrelationships among competitors.

Effects of Climate Change on C 4 Plant List and Distribution in South Korea:A Review

It is expected that identification and lists of plants in specific regions are useful not only for the ecological researches that are related to vegetation phenology and succession but also as an index of climate change. In this review, plants growing in South Korea were listed and their life forms were investigated. In addition, we discussed the influences that climatic change and the plants exerted on plant ecosystem. Photosynthetic pathway types ( and ) for the plant species in South Korea were determined by reviewing the scientific literatures published between 1971 and 2010. Of the total 4476 species in 1123 genera and 197 families, 206 species (4.6%) in 84 genera (7.5%) and 21 families (10.7%) were identified as plants (including - intermediate plants). Among the identified species, 53 species (25.7%) in 26 genera and 15 families were classified as Dicotyledoneae, while 153 species (74.3%) in 58 genera and 6 families were classified as Monocotyledoneae. The majority of the species belong to four families: Chenopodiaceae (15 species), Amaranthaceae (13 species), Gramineae (102 speceis) and Cyperaceae (45 species). With respect to life form composition of 206 species, Th---t was most dominant: 95 species (46.1%) were included in Th, 123 species (59.7%) in , 179 species (86.9%) in , and 122 species (59.2%) in t. The projected increase in temperature due to climate change may provide better conditions for the growth of plants. Such a result will have considerable impacts on the interspecific competition between and plants, the distribution of plants, plant phenology, and plant diversity.

Distribution Characteristics of Water Scavenger Beetles (Hydrophilidae) in Korean Paddy Field

Aquatic invertebrates are the major important fauna to sustain the paddy ecosystem as predators of the lower trophic level and prey for birds in food-web dynamics as well. The nationwide distribution of scavenger beetles (Hydrophilidae) that is the top predator in an aquatic insect in the paddy field was investigated. A total of 15 scavenger beetles were recognized. Enochrus simulans (98.6%) and Laccobius bedeli (87.7%) showed a high frequency of occurrence on a nationwide scale. The majority of scavenger beetles were higher frequency of occurrence in mountainous regions(33.7%) than in open field regions(5.0%). On the other hand, E. uniformis, Coelostoma stultum and Berosus japonicus showed a low occurrence frequency. Hydrochara affinis, Sternolophus rufipes, Amphiops mater, B. elongatulus, B. signaticollis punctipennis, B. lewisius and H. libera showed regional specific distribution aspect. Therefore, these species can be used as biological index to research the biotic changes in paddy ecology according to an agro-environmental changes including climatic change in the future.

Differential regulation of heat shock protein genes by temperature in relation to initial diapause in the egg of the katydid Paratlanticus ussuriensis

The lifecycle of Paratlanticus ussuriensis Uvarov can extend for longer than 1 year (plurennial) as a result of prolonged diapause. Eggs can overwinter by entering a facultative initial diapause in the early embryonic stage within the egg, followed by further overwintering by entering an obligatory final diapause at the fully developed embryonic stage. The initial diapause is temperature‐dependent and initiated by continuous incubation at 20 °C but not at 30 °C. To understand the mechanism of initial diapause at the molecular level, cDNAs of small heat shock protein genes (shsp), hsp90, as well as three hsp70 genes (hsp70a, hsp70b and hsp70c), are determined and the transcript levels of the five hsp genes are compared in eggs incubated at 20 or 30 °C for 60 days after oviposition using real‐time reverse transcriptase‐polymerase chain reaction analysis. At 30 °C, transcript levels of shsp, hsp70a, hsp70b and hsp90 increase in eggs with age. However, hsp70c levels uniquely peak only in 25‐day‐old eggs, corresponding to the time of initial diapause. At 20 °C, distinct levels of shsp, hsp70a and hsp90 appear in some stages and fluctuate throughout the 60‐day observation period, although both hsp70b and hsp70c are undetectable. These results suggest that each hsp may play a specific role in relation to initial diapause. In addition, up‐regulation of hsp70c may be associated with the mechanism of embryonic activation for averting initial diapause in warmer conditions.

Biodiversity of Inhabitants of Animals and Vascular Plants in Korean Paddy Fields Ecosystem

Biodiversity is one of the most important issues discussed worldwide, and each country has various policy measures to preserve its diversity. Efforts to preserve and improve our ecosystems have been an important issue in the agricultural sector. Especially, rice paddies are recognized in the scientific community as an important wetland system globally by the Ramsar convention. Rice paddies have formed a typical agricultural landscape for centuries in many areas including Asia.

The Physio-chemical Variation of the Host Plants and Feed Preference of the Ussur Brown Katydid, Paratlanticus ussuriensis (Orthoptera: Tettigoniidae)

In 2006 and 2007, there was a big outbreak of the Ussur Brown Katydid, Paratlanticus ussurriensis in the central part of Korea attacking some orchard trees. Until 2000, the katydid had not been regarded as an agricultural pest because they were distributed widely in Korea with low population density and their habitats were confined mainly to hillsides of forested areas. The fact that katydid attacked orchard trees with a higher population density seemed to be related to a change in feeding environment. And the shift of their habitats from oak woodlands to commercial orchards was thought to be related to the nutritional contents of their feed. In an attempt to understand these relationships, we conducted an ecological study of the affected areas. When the katydids changed their habitats in early May of 2008 and 2009, they shifted their host plants from oak trees to peach trees. The habitat shift was closely related to the nitrogen (N) content of the host plant leaves. When katydid moved to the hillside adjacent to orchard farm, N content of oak tree leaves decreased dramatically from 5.3% to 2.2%. At that time N content of peach tree leaves were higher than the 2.2% of oak leaves, showing 3.5~5.0%. This range of N content of peach tree leaves has been consistent until late June. And feed preference analysis carried out in the laboratory showed that katydid prefered peach tree leaves to peach fruit to oak tree leaves.