• Korean journal of applied entomology
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• v.32 no.3
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• pp.338-347
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• 1993

The study was to investigate the bionomics, host plants, and oviposition preference of Hishimonus sellatus Uhler. It has 5 generations under natural conditions and the peak of the 3rd generation was observed about mid and late August. Its average developmental durations were 80 days in spring, 69 days in summer, and 77.8 days in autumn. The lengths of each stage were 0.8mm in eggs, 0.9mm in 1st instar, 1.4mm in 2nd instar, 2.1mm in 3rd instar, 2.5mm in 4th instar, 3.2mm in 5th instar, 4.1mm in female, and 3.8mm in male. Hishimonus sellatus overwintered as egg in Morus alba, Humulus japonicus, and Zizyphus jujuba begining mid October, and attacked the shoot of M. alba and H. japonicus about mid and late May, migrated to the Zizyphus jujuba from late June to early July. Female oviposites 32~62 eggs into epidermis of shoot, vagina and vein during their life. The preferred host plants of H. sellatus were Humulus japonicus, Morus alba, Zizyphus jujuba, and ligustrum obtusifolium. Highly preferable oviposition site was H. japonicus, M. albal, Z. jujuba, and L. obtusifolium, etc. On audlt longevity, the host plants as H. japonicus, M. alba, and Z. jujuba were 43$\pm$2 days and A. brevipedenculata, C. mimosoides, L. obtusifolium, V. rosa, A. sinicus and, A. graveolens were more than 25 days, and other host plants were less than 20 days.

• Journal of Korean Society of Forest Science
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• v.96 no.6
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• pp.750-755
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• 2007

This study was investigate to ecological characteristic of Trioza ukogi (shinji) on the Acanthopanax senticosus for. inermis Harms during 2004-2005 in Korea. The sizes of Trioza ukogi (shinji) were $0.40{\pm}0.03mm$ in eggs, $0.36{\pm}0.03mm$ in 1st instar nymphs, $2.50{\pm}0.25mm$ in mature nymphs and $5.17{\pm}0.28mm$ in adults (to tip of folded wings), respectively. T. ukogi has two generations per year. First generation appeared from mid-July to late August with peak in early August. Second generation appeared from mid-September to mid-October with peak in late September. Overwintering adults move to host tree and mate from the early April to late May with peak in late April. Overwintering female laid on the new leaves and first generation prefers to lay on the seeds. The number of ovarian eggs was 5$57.5{\pm}23$.

• Korean journal of applied entomology
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• v.37 no.2
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• pp.137-142
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• 1998

The regional distribution and some ecological characteristics of Chinese white-wax scale, Ericerus pela Chavannes, were investigated from 1996 to 1997. It was found that 10.8% of the stems of the privet, Ligustrum obtusifolium infested with the scale in Chtingpyijng, whereas only 1.1% of them infested in Y6ngwol and Pyongtaek. The average survival rate of the female adult marked 85.3% after it hibernated on the privet, Ligustrum obtusifolium. A female laid 7,783.5 eggs in average and 36.7% of females fell on the range of 7,000-10,000 eggs. It sized 0.40 mm in length and 0.21 mm in width. The hatchability was highest at 27$^{\circ}$C with 66.8% and it seemed the optimum temperature for incubation. The pupation rate was lower than 50.0% at the above experimental temperatures and the emergence rate marked 67.3% at 25$^{\circ}$C. When the egg was preserved at the various low temperatures, it was found that the egg could be preserved at lS$^{\circ}$C for 50 days in maximum.

• Korean Journal of Environment and Ecology
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• v.31 no.2
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• pp.135-151
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• 2017

Waterbirds were surveyed once a week from Oct. 2015 to Apr. 2016 to study the conditions of temperature of staying waterbirds on Wonju-Stream. The population staying on Wonju-Stream was in inverse proportion to the temperature change; birds increased as the temperature went down, and showed the highest peak counts on the 16th(27-Jan) survey, which was the lowest in temperature. decreasing as the temperature rose. The total population of Wonju River water birds increased with increasing freezing rate in proportion to the freezing rate of nearby reservoirs and tributaries. To clarify the relation of the numbers of the birds to temperature fluctuation, the correlation of the first period of wintering (1st~16th) and that of the later period(17th~27th) as well as the whole period was surveyed, based on the 16th which was the lowest in temperature. While most wintering waterbirds showed a negative correlation to the temperature, Egretta garzetta, Phalacrocorax carbo, and Ardea cinerea were positive in temperature relativity. Anas poecilorhyncha was in the highest relation to temperature fluctuation showing (7D/H3A(r=-0.960, P<0.000000001)) at 1-16 correlation(Cor.), with the whole wintering waterbird species showing the maximum correlation at 4D/LA in the every correlation(1~27Cor.(r=-0.942, P<0.01), 1~16Cor.(r=-0.947, P<0.01), 16~27Cor.(r=-0.958, P<0.01)). Each waterbird showed the correlation to the temperature variation(AT, HT, LT) and th duration(1D~7D) depending on the species differently. Most species demonstrated a bigger correlation to the lowest temperature rather than to the highest temperature. During the first half period of the wintering with the temperature falling it showed a high correlation to the temperature at the duration of 4D~7D, While it was for D1~D3 during the next half period.

• Research in Plant Disease
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• v.10 no.4
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• pp.290-296
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• 2004

Bacterial blossom blight is one of the most important diseases of kiwifruit (Actinidia deliciosa). The disease occurs during flowering in the late May and disease outbreaks associated with rainfall during the flowering season have resulted in a severe reduction in kiwifruit production. The causal organism isolated from diseased blossoms of kiwifruits was identified as Pseudomonas syringae pv, syringae based on the physiological and biochemical characteristics and pathogenicity test. Dead fruit stalks, dead pruned twigs, fallen leaves and soils mainly provided R syringae pv. syringae with overwintering places in the kiwifruit orchards, and the inocula also overwintered on buds, trunks, branches, and twigs on the kiwifruit trees. Among the overwintering places, the incula were detected in the highest frequencies from dead fruit stalks. The population density of P. syringae pv. syringae was speculated to be over $1{\times}10^4$cfu/ml for the bacterial infection, and the optimum temperature for the bacterial growth ranged 20 to $25^{\circ}C$. The highest population density of P. syringae pv. syringae on the overwintering places was detected in May and June when the daily average temperature coincided with the optimum temperature for bacterial growth of P. syringae pv. syringae.

• Korean journal of applied entomology
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• v.34 no.3
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• pp.249-255
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• 1995

These experiments were conducted to investigate the life history and the seasonal fluctuation of population density of tea red spider mite, Tetranychus kanzawai Kishida and to observe its natural enemies in the southern area. Under field-cage conditions, tea red spider mite occurred 11~12 generations. The average periods from egg to adult emergence were 8.7~13.1 days in summer and 12.6~24.9 days in spring and autumn. The average longevities of adults were 15.5~21.9 days in summer and 25.1~31.6 days in spring and autumn. The average number of eggs laid per female were 45.1 in summer and 52.6 in spring and autumn. Tea red spider mite population showed two peaks during April-June, and appeared third or forth peak during October-November. The density of all the stages was the lowest in July through August. Tea red spider mites stayed at lower parts of tea plants in March but they moved to upper parts in April though June, and they again moved to lower parts after autumn. Tea red spider mite overwintered as all stages. Adults were the dominant overwintering stage during this stage. The surveyed natural enemies of the tea red spider mite were 7 species including Amblyseius longispinosus (Evans), A. eharai Amitei et Swirski, Anystis baccarun (L), Agistemus fleschneri Summers, Orius sauteri Poppius, Oligota yasumatsui Kistner and Scolothrips sp.

• Weed & Turfgrass Science
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• v.4 no.1
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• pp.35-43
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• 2015

To assess the dormancy associated weedy risk of the F1 hybrid generated by hybridization between Brassica juncea (maternal) and Brassica napus (paternal), seed germination, dormancy and longevity were examined sequentially after seed harvest. The F1 hybrids exhibited the intermediate characteristics of their parents in seed germination and dormancy with relatively high dormancy rate of 41.1%. In summer, F1 hybrid seeds buried in the 3 cm soil exhibited greater viability (52.4%) than those in the soil surface with greater seed longevity (74.6%) than its maternal (63.3%) and paternal (33.7%) parents at 100 days of over-summering in soil. In winter, F1 seeds buried in the soil surface were more viable than those in the 3 cm soil with greater seed longevity (83.5%) than its maternal (39.0%) and paternal (71.7%) parents at 100 days of over-wintering in soil. Therefore, it is concluded that F1 hybrid resulted from gene flow from OSR to mustard has high seed dormancy and longevity during summer and winter, suggesting its weedy risk potential. Further studies are required to examine the reproductivity and fitness cost of F1 hybrid to make a clearer conclusion of its weedy risk.

• Korean journal of applied entomology
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• v.23 no.1 s.58
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• pp.42-48
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• 1984

The developments of overwintering larvae of the peach fruit moth, Carposina niponensis Walsingham, were studied in Suweon. Among fully grown larvae leaving from apple fruit, the earliest diapause larva was observed late July, about $50\%-diapause$ in middle August and $100\%-diapause$ in early September. Induction of the diapause seemed to have relationships with the time of oviposition: the incidents of the diapause started with the larvae grown from the eggs which had been laid in late June or late July depending on the prevailing weather condition. The termination of the diapause seemed to be in early December, and almost all of the larvae incubated after January were pupated. For the breakage of the diapause, it required chilling period more than one month, and the most effective temperature seemed to be $5\~10^{\circ}C$, while the temperature lower than $0^{\circ}C$ seemed to be inhibitory, if not at all. The overwintered larvae started to pupate in middle May, and the developments of the over-wintered larvae were affected by the temperature as well as the moisture contents of soil in the spring. The dry condition of soil increased the mortality of the developing larvae.

• Korean Journal of Environment and Ecology
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• v.30 no.5
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• pp.848-856
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• 2016

The purpose of this study is to determine the impact on settlement pattern of wintering swans by distribution of rapidly spreading lotus in Junam reservoir. When we investigated the relationship between the spreading lotus and population variation of the wintering swans in all around Nakdong-river estuary, the spreading lotus did not affect the number of swans in Junam reservoir. The occupation ratio of lotus distribution continuously increased from 13.2%(2013) to 19.0%(2014). Before we begin with the investigation, we compared two particular groups: inside of lotus community and far (>100 m) water area from the border of lotus community. At the first survey(2013.12.17), we observed 3.1 times more swan population in the inside, comparing with far water area. The third(2014.01.29.) and fourth(2014.12.03) inquiries also showed respectively 5.5 and 7.5 times higher swan population in the inside and near water area. The second observation was conducted during visitors were increased so these phenomenon was not observed. This result might be explained as the similar environmental condition of habitate for swan and lotus such as less than 1 m water depth. However, we considered that lotus and swan were not relation of conflict due to increasing both lotus community and swan population at the same time. According to the observation that inhabitation density of wintering swans is significantly high in near lotus communities area, at least spread of lotus did not negatively affect the wintering swans.

• Korean Journal of Ecology and Environment
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• v.42 no.1
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• pp.58-66
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• 2009

The telemetry of eight adult manchurian trouts (Brachymystax lenok tsinlingensis) in the upper part of the Nakdong River, which is the southern limit of distribution of manchurian trout on the Korean peninsula, was used to examine migration patterns and evaluate characteristics of over-wintering and the spawning season between December, 2007 and May, 2008. Based on the tracking data, the tagged fish showed a limited migration between adjacent pools, moving only up to $8.6m\;day^{-1}$ during the winter season (December to February). Hydraulic conditions of over-wintering pool areas were, ca. 1m depth, slow moving surface water with areas of sand and gravel. The migration of tagged individuals was successful, moving up to $96.2m\;day^{-1}$ during the spawning season. Two tagged individuals (BL4, BL6) exhibited upstream migration, whereas others showed downstream movements. The timing of upstream migration of the two individuals was consistent with an increasing phases of water level and discharge. The fishes migrating toward the down stream moved to the wide pool areas downstream, where they spent the summer season for the growth.