• Korean journal of applied entomology
• /
• v.40 no.2
• /
• pp.117-123
• /
• 2001

The occurrence and damage by the oriental fruit moth, Grapholita molesta (Busck) were investigated on pear trees from 1996 to 2000 in the Naju, Korea. The number of overwintering larvae in pear trees considerably varied depending on the maturation time of varieties. The density of overwintering larvae on late cultivars such as Gamcheonbae and Okusankichi was high, but relatively low on early cultivars. Trunk and main branch of pear trees were main overwintering sites. In 1997, overwintering larvae began to pupate from middle February, and to emerge from late March. Male moths were caught in the sex pheromone traps from late March until early October with four peaks of flight in 1996~2000. In every generation larvae damaged both the shoots and fruits of pear tree, but the first and second generation larvae tended to damage mainly shoots, while most of the injured fruits were due to the third and fourth generation larvae. In pear fruits damaged by fruit moths, most of these were caused by oriental fruit moth larvae and none of pear fruits were damaged by peach fruit moth or pear fruit moth larvae in 1998~2000.

• The Korean Journal of Zoology
• /
• v.38 no.3
• /
• pp.348-355
• /
• 1995

This Investigation was carried out to map the morphological development of serotonin-immunoreactive neurons in the larval brain of the cabbage butterfly, Artogeia rapae, during five larval stages. Both the first instar larva and the second instar larva contained twenty serotonin-immunoreactive (5-HTi) neurons in each brain. The fibres of 5-HTI commissure was interconnected to two cerebral hemispheres in both brains. However, the 5-HTi commissural fibres was Increased in number in the second-instar larva brain. In the brain of the second Insar larva these 5-HTi fibres formed rich arborization in contralateral neuropils, especially In the posterior parts of it. The third-Instar larva braIn, which Included twenty two 5-HTi neurons, had three groups of 5-HTi commissural fibres. In the fourth Instar larva, the number of 5-HTi fibres as well as 5-HTi cell bodies increased in the brain. The fifth-instar larva brain, which contained fifty four 5-HTi cell bodies, showed the largest number of 5-HTi cell bodies In developing larval brains. The 5-HTi fibres formed richest commissural fibres and some of them run parallel to anteroposterior axis.

• Korean journal of applied entomology
• /
• v.37 no.2
• /
• pp.163-170
• /
• 1998

Larval morphological characters such as body color and stripe pattern were analyzed to get morphological genetic markers of beet armyworm, Spodoptera exigua (Hiibner). Body color was varied from light green to dark brown with diets. Stripe characters were classified by the presence of dorsal and lateral lines: three stripes with both lines, one stripe with dorsal line only, and zero stripe. Proportions of each stripe character increased with successive selections for its own character. Three stripe was dominant to one stripe when they were crossed. The estimated heritability in narrow sense (h2) of the stripe pattern was 0.50k0.42. About two fold more females than males were produced in zero stripe line. Stripe pattern was not significantly changed by different diets except in welsh onion which had lower proportion of three stripe individuals than that of the expected. Larval stripe pattern was also correlated with larval and pupal developmental rates and cold hardiness but not with insecticide susceptibility.

• Parasites, Hosts and Diseases
• /
• v.24 no.2
• /
• pp.109-114
• /
• 1986

In order to observe the growth and development of Fibricola seoulensis metacercariae, the tadpoles of Rana nigromaculata were experimentally infected with the cercariae. The meta cercariae of various developmental stages were recovered from the tadpoles after 2 to 65 days of infection. They were prepared for morphological observation, and were given orally to mice to observe their infectivity. The following results were obtained. 1. All of the tadpoles exposed to the cercariae were observed to harbour the larvae in their abdominal cavity. 2. The young metacercariae of 2 days after infection were $121.1{\mu}m$ long and $63.3{\mu}m$ wide. They grew linearly for the first 14 days to be $262.0{\mu}m$ long and $166.4{\mu}m$ wide. Thereafter, no more growth recognized until 65 days. 3. The larvae of 2 days old were similar with cercarial body and had 2 suckers, a pharynx, 2 ceca and a primordium of germ cells but no tribocytic organ. On the 8th day, they had tribocytic organ, and their morphology resembled that of mature metacercariae. 4. The metacercariae younger than 10 days could not infect the mice. Only the metacercariae older than 14 days had infectivity. The recovery rates increased by the age of metacercariae from 19.0% in 14 days old to 70.0% in 40 days old. Above findings indicate that the tadpole is indispensable for metacercarial development and it needs at least 2 weeks for maturation. The tadpole is a pivotal host in the life cycle of F. seoulensis for connection between the snail and the frog.

• Journal of Korean Society of Forest Science
• /
• v.9 no.1
• /
• pp.45-48
• /
• 1969

The objective of this research was to investigate the seasonal trends in the population of the larvae of the Pine gall-midge in the spring at field. 1. The comparative ratio in the number of larvae of the Pine gall-midge was 100 in early spring, 29 at April 15th and 10 at May 4th. 2. Probably, the seasonal decrease in the number of larvae at field may be due to the gradual rising in the temperature and decreasing the relative Humidity season the experiment was conducted. 3. Water selection method gave best results in collecting the larvae from soil.

• The Korean Journal of Zoology
• /
• v.5 no.1
• /
• pp.21-29
• /
• 1962

본논문은 경기도광릉시험장에서 잣나물을 식해하는 잣나무넓적잎벌의 생활사를 1958-1961년에 조사연구한 것을 보고하는 것이다. 본충의 생활사에 대한 연구는 동양에서 아직 보고된 바 없다. 1) 광릉에서는 6월중순부터 7월 하순에 걸쳐서 성충이 출현한다. 생활기간은 성충이 5(웅)-6(자)일, 란이 약 6일, 유충이 약 23일, 전용이 약 10.5개월, 용이 약 8일이다. 2) 산란은 신생침엽의 내측에 행하고, 1자충의 산란수는 38립가량되고, 일란을 산촌하는데 소요되는 시간은 약 3분간이다. 3) 유충은 5령을 경과한다. 유충은 토사에 의하여 침엽을 얽어서 집을 만든다. 이 소내에 보통 1마리의 유충이 서식한다. 4) 유충의 식초는 한국에 있어서는 잣나무뿐이다.

• Parasites, Hosts and Diseases
• /
• v.21 no.1
• /
• pp.111-117
• /
• 1983

1979∼1980연 칠월초에 서부 비무장지대 (DMZ)에서 모기 유충채집을 실시한 바 Aedes alboscutellatus의 유충을 제집하여 사육한 결과 성충(♀,♂), 완전유충, 유충 및 편의 탈피각등 분류에 필요한 자료를 얻었다. 이 종은 Reisen등(1971)에 의하여 한국에서 처음 성충(♀)채집을 기록하였으나 이를 확증할 만한 표본이나 분류학적인 기재가 없어 분류상의 오독으로 간주되어 왔었다. 저자등은 본 채집을 통하여 분류상 필요한 모든 자료를 수집하였기에 성충(♀, ♂), 유충, 항, 자충생식기등의 특징을 Reinert(1973)의 기재와 상세히 비교 검토한 결과 웅충에서 gonostylar claw와 basal mesal lobe에 있는 강모의 수가 다르고 자웅충에서는 subspiracular area에 횐 비늘들이 모여있는 점을 발견하였다. 그러나 이들 차이점을 여기에서는 단지 지리적 변화로 간주하였으므로 더 많은 수의 채집을 통하여 보다 확실한 구각이 요구된다 이 표본의 장기보관을 위하여 암수 각 한개섹의 표본과 그에 수반되는 유충 및 편의 탈피곡 표본을 미국 Smithonian연구소에 보냈으며 나머지는 미 8군 예방의무부 곤충연구실에 보관되어 있다.

• Korean journal of applied entomology
• /
• v.32 no.2
• /
• pp.134-138
• /
• 1993

Larval densities and spatial distribution patterns of beet armyWorm, Spodoptera exigua, were studied in the welsh onion field located in Asan from June to November, 1991. During the period, there were two denslty-peaks;mid August and mid~late September. The larvae showed clumped distribution patterns. but the patterns changed into random as larval density decreased in Oct.ober. Each larval instar showed clumped pattern expect 6th instar surveyed on September 25, which distributed in a random pattern. The larval distribution pattern were also influenced by the host plants;clumped pattern on such host. as red pepper and welsh onion, versus random pattern on such hosts as chrysanthemum, peanut and soybean.

• Korean journal of applied entomology
• /
• v.32 no.2
• /
• pp.225-235
• /
• 1993

This study was carried out to investigate effects of diazinon, an organophosphate, and nicotine, a plant~originated toxic chemical, on larval mortality and activity of cytochrome P-45D monooxygenases, a major detoxifwation enzyme system, in Helicoverpa assulta and Spodoptera exigua. Diazinon treatment gave a higher mortaliLy to H. assulta larvae than S. exigua larvae. In contrast to the case of diazinon, nicotine caused a higher mortahty to S. exigua than to H. assulla larvae. It was partly due to the fact that nicotine induced the actiVIty of midgut cytochrome P-450 monooxygenases (MFO) more than diazinon did in If assulta larvae. When If. aSSlllta larvae were reared on their host p\am. NicotwlIa tuoocum leaves, other componentS were mostly metabolized with the exception of dietary nicotine.

• 한국해양학회지
• /
• v.30 no.3
• /
• pp.197-202
• /
• 1995

A total of 272 specimens of Todarodes pacificus purchased during the period from July 1 to August 30, 1994 in the southern sea off Pusan were examined for their infection status with larval anisakids. Larvae in squids were encapsulated and appeared to remain active. Firty five larval anisakids sorted from T. pacificus (7.72% of infection rate) were classified based on morphological and morphometric observations as follows; Anisakis type I larvae (23 larvae, 51.0%: positive rate), Contracaecum type A (9, 20.0%), Contracaecum D (4, 9.0%), Anisakis II (3, 6.7%) and unknown type (6, 13.3%).