• Proceedings of the Korea Society of Environmental Biology Conference
• /
• 2003.11a
• /
• pp.12-15
• /
• 2003

The effects of the non-steroidal ecdysteroid agonist tebufenozide on larvae of C. faviplumus and C. riparius were tested in the laboratory. In the most treatments it reached a statistically significant difference from the control condition. As the concentration of tebufenozide was increased, a relatively larger proportion of the observed mortality was associated with the metamorphosis and molting process. Also, the larval mortality of the first larvae was higher than the fourth-instar larvae in C. riparius. In terms of development, the effects of tebufenozide were delayed growth stage in relatively lower concentration such as 10 $\mu\textrm{g}$/L treatments. Based on the mortality, the susceptibility followed the first-instar C. riparius > the fourth-instar C. flaviplumus > the fourth-instal C. riparius. The morphological effects showed that the first and second segments of body of exposed larvae with tebufenozide expanded slowly and not made a complete cephalothorax of pupae during long times or days. And the head capsule slipped down and forward, revealing a fragile and non-pigmented, unsclerotized new head capsule. There was obvious significant difference in the male/female ratio in contaminated fourth larvae of C. riparius. Also, due to the different emergence periods of male/female in low insecticide concentrations, mating chances or opportunities of insects should be decreased. Accordingly, ecological strategies for keeping of sustainable populations should be disrupted.

• Animal Systematics, Evolution and Diversity
• /
• v.19 no.2
• /
• pp.277-282
• /
• 2003

The present paper is a part of the study on the immature stages of genus Tipula in Korea. It described and illustrated egg, each larval stage and pupa of Tipula nova. It is the first to deal the all immature stages of the species in Korea. Their taxonomic remarks and habitats are also given.

• Journal of Sericultural and Entomological Science
• /
• v.31 no.2
• /
• pp.72-81
• /
• 1989

Antheraea yamamai vitellin was purified from matured eggs by polyacryamide gel electrophoresis, also stage dependent appearance, immunological comparison and relative content of the protein were investigated. 1. Vitellogenin, the precursor of vitellin, was first detected in the larval hemolymph at the late spinning stage by polyacrylamide gel electrophoresis and immunoelectrophoresis. 2. The electrophoretic mobility of the vitellin was identical with that of Bombyx mori and of Bombyx mandarina. However, the specific antiserum against A. uamamai vitellin did not react with either that of Bombyx mori or Bombyx mandarina in immumo-diffusion test. 3. Relative content of A. yamamai vitellin to the total soluble egg protein was 46.0 percent and did not change till eight days after oviposition. But the content started to decline from ten days after oviposition and was negligible in the five or serventeen month old eggs.

• Korean Journal of Ichthyology
• /
• v.36 no.1
• /
• pp.94-100
• /
• 2024

During ichthyoplankton survey in the southwestern sea of Korea, we collected six individuals of noodlefish larvae and juveniles between April and May 2023. They were identified as Neosalanx anderssoni by mitochondrial DNA cytochrome c oxidase subunit I or 16S ribosomal RNA sequences, and their external morphological traits were described for the first time. All six individuals have a slender and elongated body. When preflexion and flexion larval stages (10.24 mm notochord length, NL and 15.47 mm total length, TL, respectively), oval-shaped black melanophores were distributed in a row along the ventral side of the gut. However, when postflexion larval and juvenile stages (23.58~25.90 mm TL, and 29.20~31.26 mm TL, respectively), melanophores on the ventral side of the gut were disappeared, and dark spot-shaped melanophores appeared along the dorsal side of the gut in a single row. Also, from the postflexion larval stage (23.58 mm TL), two large black spots began to appear symmetrically on the caudal fin. Our results suggest that N. anderssoni may use coastal area as spawning and/or nursery ground unlike previous study (Kim and Park, 2002).

• Journal of Aquaculture
• /
• v.15 no.1
• /
• pp.23-29
• /
• 2002

To develop techniques for the production of artificial seedling of Corbicula japonica, protocols for induction of spawning and larval development were developed. During the assumed spawning period of August to mid-September, attempts were first made to induce spawning by gonadal incision and UV-irradiation but all in vain. At the end of August, elevated thermal induction evoked 90 % positive response in animals maintained at $3\textperthousand$ salinity. Immersion in (1/1000~3/1000 N) ammonium hydroxide ($NH_4$OH) also induced spawning in 15~45%) of the treated animals at $3\textperthousand$ salinity. Fertilized eggs measured 86$\mum. At 23.0~24.5$^{\circ}C$, the fertilized egos developed into 4-cell stage embryos within 2 hours, trochophores 15 hours, D-shaped larvae 2 days, umbo 9 days and fully grown veligers, ready to infiltrate into the sediment, within 16 days.

• Journal of Aquaculture
• /
• v.11 no.3
• /
• pp.303-310
• /
• 1998

The growth and survival rate of larvae and juveniles from female rockfish (Sebastes schlegeli) broodstock in vitellogenesis by injection of 3,5,3'-triiodo-L-thyronine $T_3$ with a dose of 20 mg/kg fish wt. were examined for 30 days and compared with sham-control fish injected dime-thyl sulfoxide and control fish. Larvae were fed with rotifers for first 5 days after parturition, rotifers and Artemia nauplii for next 10 days. And then, they were fed with Artemia nauplii and commercial diet. Growth of larvae and juveniles from maternal $T_3$injection was significantly faster than that of two controls, nevertheless, the condition factor was lower than that of controls. The whole body proximate analyses indicated that there were significant effects of $T_3$ injection on protein and lipid, but no significant on moisture and ash contents. Survival rate of the fish from maternal $T_3$injection was significantly higher than that of fish from the two controls. These results indicate that thyroid hormone supplements appear to confer a distinct advantage to larval and juvenile rockfish in early, fragile development stage.

• Parasites, Hosts and Diseases
• /
• v.49 no.4
• /
• pp.445-448
• /
• 2011

A survey was performed to find out the intermediate hosts of Gnathostoma nipponicum in Jeju-do (Province), the Republic of Korea. In August 2009 and 2010, a total of 82 tadpoles, 23 black-spotted pond frogs (Rana nigromaculata), 7 tiger keelback snakes (Rhabdophis tigrinus tigrinus), 6 red-tongue viper snakes (Agkistrodon ussuriensis), and 2 cat snakes (Elaphe dione) were collected in Jeju-do and examined by the pepsin-HCl digestion method. Total 5 gnathostome larvae were detected in 3 (50%) of 6 A. ussuriensis, 70 larvae in 3 of 7 (42.9%) R. tigrinus tigrinus, and 2 larvae in 2 of 82 (8.7%) frogs. No gnathostome larvae were detected in tadpoles and cat snakes. The larvae detected were a single species, and $2.17{\times}0.22mm$ in average size. They had characteristic head bulbs, muscular esophagus, and 4 cervical sacs. Three rows of hooklets were arranged in the head bulbs, and the number of hooklets in each row was 29, 33, and 36 posteriorly. All these characters were consistent with the advanced third-stage larvae of G. nipponicum. It has been first confirmed in Jeju-do that R. nigromaculata, A. ussuriensis, and R. tigrinus tigrinus play a role for intermediate and/or paratenic hosts for G. nipponicum.

• Korean journal of applied entomology
• /
• v.19 no.4 s.45
• /
• pp.187-192
• /
• 1980

This study was carried out to investigate the bionomics of Ostrinia furnacalis $(Gu\grave{e}n\grave{e}e)$ in the laboratory and field in 1978. The oriental corn borer had three generations a year in Korea ana the first period of moth activity was mostly from early June to early July, the second from mid July to mid August and the third from mid August to early September. It overwintered with larval stage in the corn stubbles. The egg period was 3-4 days. The larva molted 5-6 times and its period was 18-30 days. The longevity of adult was 7-11 days and deposited about 600-800 eggs. An egg parasite and two larval parasites were investigated.

• Parasites, Hosts and Diseases
• /
• v.58 no.4
• /
• pp.467-473
• /
• 2020

Chinese edible frogs, Hoplobatrachus rugulosus, were examined to estimate the potential risks of human gnathostomiasis and sparganosis in Myanmar. A total of 20 frogs were purchased in a local market of Yangon and examined with naked eyes and the artificial digestion method after skin peeling in June 2018 and June 2019. Larvae of gnathostomes and Spirometra (=spargana) were detected in 15 (75.0%) and 15 (75.0%) frogs with average intensities of 10.5 and 6.3 larvae per infected frog, respectively. Gnathostome larvae were 2.75-3.80 (av. 3.30) mm long and 0.29-0.36 (0.33) mm wide. They had a characteristic head bulb with 4 rows of hooklets, a muscular long esophagus, and 2 pairs of cervical sac. The mean number of hooklets were 41, 44, 47, and 50 on the 1st, 2nd, 3rd, and 4th row, respectively. Collected spargana were actively moving, particularly with the scolex part, and have ivory-white color and variable in size. Conclusively, it has been first confirmed that Chinese edible frogs, H. rugulosus, are highly infected with larval gnathostomes and spargana in this study. Consuming these frogs is considered a potential risk of human gnathostomiasis and sparganosis in Myanmar.

• Korean journal of applied entomology
• /
• v.29 no.1
• /
• pp.1-5
• /
• 1990

A morphological study on the immature and adult stages of Anagrus incarnatus Haliday was carried out under laboratory condition at 25$\pm$1$^{\circ}C$. The egg is sausage-shaped with a long slender pedicel. The first instar is a bag-shaped larva. The second instar larval form of A. incarnatus is similar to he "histriobdellid" stage. The antenna has 9 and 13 segments of the female and male, respectively. The first funicular segment of the female's antenna is very short, subspherical or globular type and the third funicular segment with one sensory ridge is longer than the forth. The forewing of A. incarnatus has 8-9 rows of discal hairs providing no bare space at the broadest part. The length of ovarian eggs, egg, 1st instar, and 2nd instar of A. incarnatus is 0.165, 0.215, 0.290, and 0.535 mm, respectively, and the width of each stages is 0.025, 0.057, 0.082, and 0.110 mm, respectively. The developmental periods for egg, 1st instar, 2nd instar, prepupa, and pupal stage are about 1, 1, 4, 1, 5-6 days, respectively.pectively.