• Korean journal of applied entomology
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• v.37 no.2
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• pp.159-162
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• 1998

Effect of temperature on oviposition and developmental period of Oulema oryzae K. on riceplant were investigated. With the given set of temperatures of 15, 20, 23, 25, and 28"C, developmentalperiod from egg to adult emergence was shorten as temperature increased. Average number of eggs perfemale 0. oryzae increased as temperature increased from 15$^{\circ}$C to 23"C, then decreased at 25$^{\circ}$C and 28"C. Based on this result, developmental threshold temperatures for egg was estimated to be 6.4"C. Totaleffective temperatures above the thresolds required for hatching were estimated to be 75.8 degree-daysfor egg. It seemed that the optimum temperature for oviposition of Oulema oryzae on rice plant was 23"C.a oryzae on rice plant was 23"C.quot;C.

• Korean journal of applied entomology
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• v.24 no.1 s.62
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• pp.25-28
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• 1985

Experiments were carried out to investigate the life cycle of the rice leaf beetle (RLB), (Oulema oryzae KUWAYAMA) ,yield losses by its damages, and control method in $1976{\sim}1983$ at the experimental field of Gangweon PORD. Peak occurrence of adult and larva rice beetle was late May and mid-June, respectively. Adult overwintered in the forest of mountain and move into the paddy field to lay eggs on the rice leaf from late seedling stage. A female adult laid eggs for 2 days, and egg, larval and pupal period was 9, 16, and 9 days, respectively. Leersia japonica MAKINO was damaged slightly by the beetle. The yield reduction by artifical defoliation ranged from 6 to 40% and yield reduction increased as leaf feeding delayed until mid-July. All insecicides show 100% of control value against RLB.

• Journal of Sericultural and Entomological Science
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• v.28 no.1
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• pp.54-60
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• 1986

Silkworms have been found cross infected with other microsporidia of insects in mulberry trees, forest and fruit gardens. Even the unidentified microsporidian species were not seriously pathogenic to silkworms, the silkworm egg producers lose their profit because of the elimination of eggs laid from moths which are infected with any kind of microsporidian species. Recently, the microsporidian cross infection to silkworm is in tendency of increase and the authors have investigated the field insects to examine the microsporidia. The number of species of insects infected with microsporidia was 10 and they were Boettcherisca peregrina (Robineau-Dewvoidy), Apis melifera linnaeus, Artogenia rapae Linnaeus, Tipula aino Alexander, Altica cacrulescens (Baly), Anomela daimiana Harold, Eilema griseola (Jubner), Rbalbistylun speciosum Uller, Anisodactylus signatus illiger, Oulema oryzae (Kuwayama). From the Boettcherisca peregrina (Rogineau-Desvoidy), three different species of micrsporidia were isolated and the microsporidia isolated from Boettcherisca peregrina (Robineau-Desvoidy), Apis melifera Linnaeus, Artogenia rapae Linnaeus donot have infectivity to silkworm larvae, Bombyx mori L.

• Korean journal of applied entomology
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• v.58 no.3
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• pp.239-249
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• 2019

This study was carried out to compare on the time of occurrence of 6 major rice insect pests [Lissorhoptrus oryzophilus Kusche, Oulema oryzae Kuwayama, Sogatella furcifera (Horvath), Nilaparvata lugens Stal., Cnaphalocrocis medinalis (Guenee), Mythimna separata Walker] in northern part of the Korean peninsula. Using growing degree days of the insects, we evaluated the number of occurrence generations and the time of occurrence. Over-wintering insects such as L. oryzophilus and O. oryzae showed different occurrence periods in northern regions. The occurrence period of the first generation adults was later in northeast regions than in Korean middle regions and more later both in northern alpines and in northern parts of east sea. In addition, the first adults of S. furcifera, N. lugens, C. medinalis, and M. separata occurred between June and early August. However, from late August to September, these insects showed the different occurrence periods in northern regions. Especially, the second adults of N. lugens were not occurred and the second to third generation adults of S. furcifera, C. medinalis, and M. separata showed similar occurrence properties. Based on these properties, the occurrence of major rice insect pests will be less in northeast regions, northern regions of east sea, northern inlands, and northern alpines of the Korean peninsula. However, comparing with their occurrences in northern regions of Gyenonggi and Gangwon provinces, the rice insect pests may show similar occurrence pattern in mid-korean mountains except for pyunggang and yangduk regions as well as in the southern and northern regions of Suyang-san.