• Journal of Korean Society of Forest Science
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• v.79 no.2
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• pp.115-126
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• 1990

This study was performed to find differences in phototaxis response of the larva, adult emergence, sex ratio and gall formation rate of Thecodiplosis japonensis Uchida et Inouye between two areas, north and south. Larvae from these two areas, Hweng-sung in north and Moo-an in south, both considered to be the sities of severe outbreak of the insect recently, were collected from the floor and transported to the entomology larboratory, Won-Kwang University in Iri, then overwintered. These larvae were used for various experimental purposes on various dates. The following results were obtained. 1. The sizes of larvae reached 2.45 in length, 0.70 in width for north, and 2.50 in length, 0.72 in width for sourth. It seems that the differents were not significant. 2. It is known that Leaving gall of larvae to the ground for the hibernation usually occurs on rainy days. For the larvae dispersion, the phototaxis response of the larvae was hypothesized. To check this, the author manipulated some different illumination intensities adjusting the distance between the glass tube in which 100 larvae were contained and electric bulb. The glass tubes were blackened all but except a small portion. The phototaxis responses between two areas seemed to be different particularly at low light intensities, 45, 145 and 1000 lux, The larvae from north assembled to the clear portion of the glass tube were more than 30 out of 100, however less than 30 in south sample regardless of the time passage. In either cases, the saturation points came after about 8 to 10 hours. If temperature units were used, the phototaxis curve= after 1 hour illumination between two areas provided significant differences. 3. The adult emergence of south area was lagged 10 days later than that of north area. The accumulated effective day-degrees of temperature for adult emergence were $934^{\circ}C$ for north area and $1180^{\circ}C$ for south area. The emerging duration of north area appeared to be in late May through the early of July and the peak emergence occurred in middle June that was approximately 15days earlier than that of south area. The sex ratio of female to male, regardless of area, was approximately 3 : 1. 4. The rates of gall formation of the red pine(Pinus densiflora Siebold et Zuccarini), 6-year-old seedlings, were as low as 9.94% for north area and 8.87% for south area. Through the close observation, the author presumed that the population reduction was greatly affected during the prepupa stage by relative moisture content and predators, such as spiders and ants presented on the ground.

• Korean Journal of Medicinal Crop Science
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• v.1 no.2
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• pp.115-119
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• 1993

This study was carried out to determine optimum harvest time of in vitro multiplied tuber Pinellia ternata(Thunb.)Breit from 1990 to 1992. Tuber yield and its related traits were observed with four harvest times. Plant height was 7.2cm at 6 months and 19.3cm at 24 months after planting. The number of tubers per unit area was significantly increased with the passage of growing time after planting$(78\;tubers/m^2)$, those were increased by 2.3 times in 6 months, 5.6 times in 12 months, 13.3 times in 18 months and 20.0 times in 24 months. The tuber sizes(length, width and weight) were highly enlarged during 12 to 18 months after planting compared with before or after this time. There were smaller tubers and lower tuber yields with shorter growing period, while large tubers above 7.1mm and higher yields with longer growing. It was suggested that the optimum harvest time was 18 months after planting, before over wintering rather than next year of spring, 24months after planting.