• Korean journal of applied entomology
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• v.51 no.2
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• pp.99-109
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• 2012

Seasonal fluctuations of Riptortus pedestris were investigated in four regions including two sites each at Mt. Yangseong (Munui-myeon, Cheongwon-gun), O-chang (Cheongwon-gun), and Jujung-dong (Cheongju) using aggression pheromone traps from April to November in 2010 and 2011. Aggression pheromone and aggression pheromone + soybean traps were set at all investigated sites, and the Mt. Yangseong A and B sites were investigated at a farmland (80 m, asl) and forest (200 and 300 m). The population density of R. pedestris was high in mid June, mid August, and late October in 2010 and in early May, mid June, mid September, and early October in 2011 with trivoltine. O-chang and Jujung-dong populations, which were distinguished in farmlands and forests, were highest from June to August in the farmland and in September in the forest. Similar numbers of R. pedestris were capture in the farmlands and the forest in June-August, September-November, respectively. From the results of the four regions, more R. pedestris adults were captured in the aggression pheromone + soybean trap than that in the pheromone trap. To investigate the migration route by altitude, 500 R. pedestris adults marked with fluorescent paint were released and re-caught insects were counted in traps after 10 and 20 days. The pattern of the re-caught R. pedestris indicated migration from the forest to farmlands during April-June. These results suggest that the insects did not migrate in August because food was plentiful in the forest at 200 m, but they moved to the forest during October due to the scarcity of food and for overwintering. The R. pedestris seasonal fluctuations in 2011 were affected heavily by the environment, particularly rain precipitation.

• Korean journal of applied entomology
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• v.44 no.2
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• pp.109-114
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• 2005

This study was conducted to investigate the life cycle of Tipula latemarginata Alexander in Korea. The field surveys for the life cycle of the species were carried out at the two sites of Neaseong Stream area in Bongwha County from January 2001 to December 2002. Also many individuals of the species were reared in laboratory to investigate the life cycle. T latemarginata appeared to have three generations a year under the rearing conditions at room temperature. All the processes of life cycle of the species, when reared at room temperature from September 2001 to March 2002, were as follows: Eggs usually hatched between 4 and 10 days after oviposition. First instar larvae grew rapidly and molted to the second instar in 7-9 days. Second instar larvae spent 5-7 days for next molting and third instar period lasted approximately 8-12 days. Fourth instar larvae spent 6 weeks to 5 months for pupation. Especially the duration of fourth instar larval existence was greatly lengthened and served as the overwintering stage. The duration of pupal stage was 6-10 days. In the field, T. latemarginata also appeared to have three generations a year at the favorable habitats.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.415-423
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• 2018

Aphid is a typical vector that transfers various kinds of viruses to potatoes. Therefore, it is very important to control aphids moving into potato fields. We investigated the seasonal movement pattern of aphids and its virus transmission rates mainly in the three seed potato production regions at highland in Gangwon-do, Korea. In addition, we identified the aphid species with over-wintering eggs collected from barks or twigs of total 57 tree species around potato fields in winter season. The peak time of summer and winter migration of aphid was at the mid-June and the early October, respectively. A 2.8% of total aphid trapped in yellow water-pan trap was turned out PLRV-borne, and the virus transmission rate was 15.4% by Myzus persicae and 9.1% by Macrosiphum euphorbiae. PLRV-borne aphids started to flow in from the late May, and virus transmission rate of aphid trapped in mid-June was the highest with 10.4%. Totally 14 species of aphid eggs wintered in the 17 species of trees including Acer pictum subsp. mono and Acer pseudosieboldianum at the 11 sites. In particular, because it is not certain that Betula platyphylla var. japonica and Yamatocallis hirayamae do transmit potato virus, but they over-wintered in host plants distributed over a wide area, further research on transmission ability is necessary.

• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.4
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• pp.162-173
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• 2009

Information on the expected geographical shift of suitable zones for growing crops under future climate is a starting point of adaptation planning in agriculture and is attracting much concern from policy makers as well as researchers. Few practical schemes have been developed, however, because of the difficulty in implementing the site-selection concept at an analytical level. In this study, we suggest site-selection criteria for quality Fuji apple production and integrate geospatial data and information available in public domains (e.g., digital elevation model, digital soil maps, digital climate maps, and predictive models for agroclimate and fruit quality) to implement this concept on a GIS platform. Primary criterion for selecting sites suitable for Fuji apple production includes land cover, topography, and soil texture. When the primary criterion is satisfied, climatic conditions such as the length of frost free season, freezing risk during the overwintering period, and the late frost risk in spring are tested as the secondary criterion. Finally, the third criterion checks for fruit quality such as color and shape. Land attributes related to these factors in each criterion were implemented in ArcGIS environment as relevant raster layers for spatial analysis, and retrieval procedures were automated by writing programs compatible with ArcGIS. This scheme was applied to the A1B projected climates for South Korea in the future normal years (2011-2040, 2041-2070, and 2071-2100) as well as the current climate condition observed in 1971-2000 for selecting the sites suitable for quality Fuji apple production in each period. Results showed that this scheme can figure out the geographical shift of suitable zones at landscape scales as well as the latitudinal shift of northern limit for cultivation at national or regional scales.