• Parasites, Hosts and Diseases
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• v.51 no.1
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• pp.43-49
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• 2013

Three species of tapeworms infect humans in their adult stage (Taenia solium, Taenia saginata and Taenia asiatica). The 3 are flat, opaque white or yellowish, and exceptional long segmented parasites, measuring 1 to 12 m in their adult stage. In this review, the development of the knowledge regarding the first species, mainly focused on understanding how the larval stage or cysticercus is transmitted to humans, is described. The second species is a cosmopolitan parasite that only causes taeniosis and not cysticercosis; therefore, it will not be included. Information on the third species, which is presently being produced, since this species was recognized as such only at the end of the 20th century, will be discussed at the end of this review.

• Biomedical Science Letters
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• v.27 no.4
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• pp.239-247
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• 2021

The scuttle fly is a fly species in the Phoridae family. Scuttle fly which moves abruptly after standing for a while and stop suddenly to rush off again. These characteristic behaviors of the scuttle fly seem to be related to muscular and nervous system or neurotransmitters. Thus, we focused at the neurotransmitter, corazonin (Crz) that is known to be related to resistance to stress and investigated the developmental process of the neurons in the scuttle fly. In a previous studies, we found that there are three groups of corazoninergic neurons in the larval CNS of the scuttle. Larva has 3 pairs of Crz neurons at the dorsolateral area of the brain, 1 pair at the dorsomedial brain and 8 pairs at the ventral nerve cord. In this studies, among these neurons, 1 pair of dorsomedial brain and 8 pairs of ventral nerve cord disappear in early pupal stage after metamorphosis. Only the 3 pairs of dorsolateral brain persist expression of Crz gene through all the period of pupa stage. This group of neurons converge gradually to frontal center of the brain and situated at the medial region. These pairs of corazoninergic neurons keep their number and location in adult stage. In the future, we expect further studies on the histological characteristics of corazonin-expressing cells and the expression of corazonin gene.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.421-429
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• 2016

Tenebrio molitor larvae contain large amounts of proteins, lipids and other functional materials, enabling this insect to be used as an edible food source in animal feeds and for industrialization. Although many efforts have been made to set up mass rearing systems, few studies have been conducted to establish optimal rearing conditions for the production of high quality T. molitor larvae. Herein we investigated 1) the effects of additional diets on the survival and fecundity of the insect, 2) the relationship between oviposition period and the uniformity of larval size, 3) the effects of rearing density and temperature on insect development, and 4) the storage stability of eggs and pupae at low temperatures given possible temporary production discontinuation. The addition of carrot and zucchini to the traditional wheat bran diet significantly increased the survival and fecundity rate of adult T. molitor. Of the three different oviposition sampling periods (3, 7, and 14 days) used to investigate the uniformity of the hatched larvae in each treatment, the period of 3 and 7 days provided higher uniformity than the 14 days oviposition period. Larval development was faster at $30^{\circ}C$ than at 20, 25, and $35^{\circ}C$. Interestingly, oviposition rates were highest at $20^{\circ}C$ but showed much slower larval development and lower uniformity at $30^{\circ}C$. Regarding the effect of larval rearing densities (1, 10, 20, 30, 40, and 50 larvae per 90 mm diam. dish), larval weight was significantly reduced at higher rearing densities, but larval longevity and length were not influenced by rearing density. The 30 larvae/dish is suggested to be a reasonable density to be applied to mass production systems. When kept at $4^{\circ}C$, T. molitor eggs showed a significant reduction in hatching rate; however, when stored under the same conditions, pupae emergence rates remained high until 10 weeks, suggesting that storage at low temperatures is more suitable for the pupal stage than the egg stage. Our findings suggest that an increase in T. molitor adult survival and fecundity rates and a uniformity of hatched larval development can be achieved with the following recommendations: a combination diet (including wheat bran), a 7-day oviposition period; a larvae-rearing temperature of $30^{\circ}C$, a rearing density of 30 larvae/dish, and the storage of pupal stages at low temperatures in the case of rearing discontinuation. This study serves as a strong foundation for the successful mass production of high quality T. molitor larvae.

• Korean Journal of Ichthyology
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• v.22 no.1
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• pp.9-16
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• 2010

Osmoregulatory capabilities of a euryhaline medaka, Oryzias dancena (Beloniformes; Teleostei), was examined with a particular emphasis on adult and larval viability during direct salinity changes. O. dancena adults were highly capable for hyper-osmoregulation as well as hypo-osmoregulation, as evidenced by no adverse effect on their viability during the direct transfer either from complete freshwater ($0^{\circ}/_{\circ\circ}$) to $40^{\circ}/_{\circ\circ}$ salinity, or from $70^{\circ}/_{\circ\circ}$ to $0^{\circ}/_{\circ\circ}$. Furthermore, the phased increase of external salinity with acclimation periods allowed them to survive at a salinity as high as $75^{\circ}/_{\circ\circ}$. However, tolerant capability to acute salinity increase in early larval stage was much less than in adult stage, based on the finding that the tolerance range of salinity increase was only $15^{\circ}/_{\circ\circ}$ from freshwater, indicating that the hyper-osmoregulation system might not be fully developed in the early larval stage. On the contrary, the hypoosmoregulation system could be more solidified in O. dancena larvae, as evidenced by their good survival even after direct transfer from $45^{\circ}/_{\circ\circ}$ to $0^{\circ}/_{\circ\circ}$. Knowledge achieved in this study could form the basis for a wide scope of researches including ecotoxicogenomics and geneexpression assay using this model species.

• Korean journal of applied entomology
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• v.60 no.4
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• pp.449-462
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• 2021

We analyzed the effects of temperature on the survival, development, and reproduction of the non-diapause Asian corn borer, Ostrinia furnacalis (Lepidoptera: Crambidae). A 16:8 h light:dark photoperiod was supplied to the non-diapause stages of O. furnacalis. The insects were raised on an artificial diet at seven constant temperatures between 15 and 35℃ for immature stages, and eight temperatures between 13 and 33℃ for the adult stage. The survival rate of eggs exceeded 70% at all temperatures, whereas survival of larvae was as low as 7.4% at 15℃. The developmental periods of the immature stages decreased with increasing temperature, but the larval period did not decrease further at 35℃. The pupal weight increased with increasing temperature, but the female weight decreased at 35℃. Variations with different last larval instars within the colonies at different temperatures were observed. Adults produced offspring at all tested temperatures. Adult longevity and the pre-oviposition and oviposition periods decreased with increasing temperature, but the pre-oviposition period increased at 33℃. Total fecundity exceeded 400 viable eggs at 22℃ and 31℃. The mean daily fecundity during the oviposition period and the mean daily fecundity on the day of oviposition increased with increasing temperature, but decreased at 33℃. Daily fecundity sharply increased at earlier adult ages and slowly decreased thereafter. The simulated oviposition frequency was greatest at 22℃. The lower developmental threshold temperatures were estimated to be the lowest at 9.7℃ for the first instar larva and the highest at 14.7℃ for the 5th to last instar larval stage, using a linear model.

• Parasites, Hosts and Diseases
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• v.34 no.3
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• pp.161-168
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• 1996

We observed the morphological characteristics and identified the species of gnathostome larvae obtained from the imported Chinese loaches. The early third-stage larvae ($EL_3$) were collected from viscera of the loaches and a part of them were infected to mice. The advanced third-stage larvae ($AdL_3$) were recovered from the mice at 4 weeks post-infection. both larval worms were fixed loth 10% formalin, cleared in alcohol-glycerin solution, mounted with glycerin-jelly, and observed. A total of 369 $EL_3$ were collected from viscera of 9,493 Chinese loaches. The whole body of $EL_3$ was covered with about 190 transverse rows of minute cuticular spines and $0.624{\;}{\times}{\;}0.101{\;}mm$ in average size. A pair of lips were protruded at the anterior end, and the muscular esophagus and brownish intestine were followed. The characteristic head bulb was provided with 4 rows of hooklets. The average number of hooklets in the respective row was 36.7, 39.5, 41.6 and 44.3 posteriorly $AdL_3$ was $2.660{\;}{\times}{\;}0.346{\;}mm$ in average size, and retained the esophagus (about 0.755 mm length) and cervical sac (about 0.355 mm length). The average number of hooklets in the respective row on the head bulb was 39.0, 41.9, 43.9 and 45.6, posteriorly. On the basis of the morphological characteristics, they were identified as the third-stage larvae of Gnathostomc hispinun.

• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.327-331
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• 2006

This study was carried out to determine the economic injury level of the rice leaffolder,Cnaphalocrocis medinalis G.. The damage aspects of rice plant (at tilling stage) by leaf folders at different larval density per plant were studied in pot experiment (24 cm in diameter, 18 cm in height). One leaf folder consumed 6-7 leaves during larval stage. The damage by leaf folders was simulated by cutting off 0, 10, 30, 50, 70, and 90% of leaves before and after heading stage July 15th (at panicle initiation stage) and August 15th (at milk stage), respectively. When leaves were cut before the heading of rice, the linear relationships between the leaf cutting rate (X) and each factors of yield (Y) were as following; for grain maturity it was Y = -9.379X + 83.630 ($R^{2}=0.493$),\;Y = 0.139X + 0.490 ($R^{2}=0.925$) for yield, and Y = -4.880X + 81.116 ($R^{2}=0.665$) for head rice. When leaves were cut after the heading of rice, it was Y = -23.0l4X + 83.589 ($R{2}=0.915$), for grain maturity, Y=0.141X + 3.466 ($R^{2}=0.842$) for yield, and Y = -13.795X + 81.964 ($R^{2}=0.898$) for head rice. We found that when leaf cutting after the heading stage caused more damage than before the heading in terms of yield and yield components. Based on theses results the economic threshold level was estimated to be 30% and 7% leaf loss before and after heading stage.

• The Korean Journal of Zoology
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• v.25 no.2
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• pp.63-70
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• 1982

The activity, properties, and distribution of midgut protease during metamorphosis in Pieris rapae L. are determined using spectrophotometer, ultracentrifuge and agar gel electrophoresis. Proteolytic activity of midgut reaches the peak just before ecdysis in 5th instar and prepupal stages each but 1 day after ecdysis in pupal stage. Also, optimum pH of midgut protease is pH 8.0 in 5th instar stage, pH 6.5 in prepupal stage, and pH 8.5 immediately before emergence respectively. Protease is found mostly in midght tissue in 5th instar stage but thereafter until just before emergence the enzyme only in lumen contents, suggesting that protease is synthesized in midgut tissue during larval stage and then released into lumen during pupation period.

• Animal Systematics, Evolution and Diversity
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• v.23 no.1
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• pp.87-89
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• 2007

The larval stage of Copera tokyoensis Asahina is described for the first time from Korea. The larva can be distinguished from other known larvae of Copera by the absence of lateral setae on the abdominal segments and by the labial palpal lobe, which bears three setae. Line-drawings of key characters and discussion on Korean Copera are provided.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2005.04a
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• pp.51-51
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• 2005