• The Korean Journal of Pesticide Science
• /
• v.13 no.3
• /
• pp.177-184
• /
• 2009

This study was carried out to investigate infection process, symptoms and main component of the domestic silkworm, Bombyx mori. larvae and pupa infected with the entomopathogenic fungus Cordyceps, Paecillomyces tenuipes. The Cordyceps, Paecillomyces tenuipes, was highly infectious to the silkworms. A pathogenicities of Cordyceps, Paecillomyces tenuipes, may be highly virulent because of the low resistance or high susceptibility of the silkworms. The silkworm larva infected with Cordyceps formed phialospores on the phialides at the imperfect stage of the genus Cordyceps, But silkworm pupa infected with Cordyceps formed ascospores in the asci at the perfection stage of the genus Cordyceps. The results of analysis of health silkworm pupa and silkworm pupa infected with Cordyceps were obtained that amino acid, fatty acid, and nucleoside were very different.

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

• International Journal of Industrial Entomology and Biomaterials
• /
• v.43 no.2
• /
• pp.59-66
• /
• 2021

Silkworm pupa has been used as an edible insect with the high quality of protein and unsaturated fatty acids. In this study, antioxidant activities of pupa according to variety, pupation day, sex, and extraction solvent were analyzed. The 30% ethanol extract showed highest radical scavenging activity compared with the DW, hexane, and 70-100% ethanol extracts. In the DPPH and ABTS radical scavenging assay according to the type of pupa, the antioxidant effect was increased in female with the early stage of pupation day. In cell-based assay, reactive oxygen species (ROS) level was decreased in pupa groups by -30 to -50% followed by tert-butyl hydroperoxide (t-BHP) treatment. The ROS levels were significantly reduced in 7^th day in each variety. In conclusion, the free radical and ROS scavenging effects were increased in female pupa with the early pupation day. The result could be used for development of bioactive materials using silkworm pupa.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.20 no.2
• /
• pp.75-77
• /
• 2010

Until now, the main treatment for impotence has been the vasodilator injection, penile implants and etc. Among many methods, most effective way is known to be the medical therapy. The oral drug for an impotence remedy has to be above all, effective to the erection, and second, safety when taking in long-term. However, so far the drug in such condition and sufficiency has not been discovered. Consequently, it is crucial to develop the new medicine, made of natural materials only, without any uncertainty of side effect. The silkworm is very difference in physiological chemical change according to growth stage. Therefore the functional effect shows a very big difference according to preparation method with a growth stage. This research carry out the experiment with the pupa powder immediately before the eclosion, eclosion adult, the pupa extract immediately before the eclosion, and the silkworm powder of 5 instar 3rd day. The result showed not a big chance in weight, feed and water intake quantity. But testosterone hormone secretion effects of the freeze drying powder of the pupa immediately before the eclosion was very high 7.31 ng/ml, compared to 2.37 ng/ml of non treatment and 2.67 ng/ml of alcohol extraction method. As this result, the freeze drying pupa powder of the pupa immediately before the eclosion was confirmed to promote the secretion of the testosterone hormone more than alcohol extraction method of existing.

• Applied Microscopy
• /
• v.12 no.2
• /
• pp.69-79
• /
• 1982

In order to define the morphological changes of the secreting cells of prothoracic gland during larva-pupal molt, ultrastructural observations were carried out using Bombyx mori L. as the experimental material. At first stage of present experiment, 4 day old 5th instar larva, the polyhedral secreting cells were centrally located in the prothoracic gland surrounded by the connective sheath. The secreting cells were attached to the neighboring cells by the prominent desmosomes, and the plasma membrane contacted with connective sheath were highly infolded. In cytoplasm, the most of the cell organelles, such as rod-like mitochondria, rough surfaced endoplasmic reticulum, ribosome were developed. As the stages advance from larva to pupa, general feature of the secreting cells were retained, but structural changes of the various cytoplasmic organelles-ribosome, rough surfaced endoplasmic reticulum, mitochondria, Golgi apparatus, lamellar body, and vesicle-were noted. In the perinuclear cytoplasm of the secreting cells at the stage of 6 day old 5th instar larva, it is peculiar that only a large amount of ribosomes were distributed and the other organelles were retreated from the juxtanuclear region. Just before and after spining cocoon, these features were more remarkable. Rough surfaced endoplasmic reticulum were gradually increased from the stage just before spining cocoon to the pharate pupa. Rod-like mitochondria with irregular cristae and the matrix showing low density were distributed throughout the cytoplasm in the secreting cells of the 4 day old 5th instar larva. Sometimes, longitudinally distended and curved mitochondria were observed. At the stage of pharate pupa, most of mitochondria were deformed. The rod-like mitochondria of the secreting cells of pupal prothoracic gland were narrower than those of 4 day old 5th instar larva, and the electron density of the mitochondrial matrix is increased in pupa. Golgi apparatus were a few in number in both stages, last instar larva and spining cocoon. In stages of the pharate pupa, the Golgi apparatus were frequently observed. Cytoplasmic vesicles were observed for the first time in the secreting cells of one day after spining cocoon, and the number and the size of cytoplasmic vesicles were distinctly increased inpharate pupa and just after pupation. In the secretory cells of the PG, it in concluded that the RER was closely related to syntheting the enzymes seem to produce the ecdysone.

• Applied Microscopy
• /
• v.12 no.2
• /
• pp.45-53
• /
• 1982

Ultrastructural changes of the testis in Pieris rapae L. observed under the electron microscope during the metamorphosis from prepupa to pupa. The peritoneal sheath, epithelium of the follicle and cucticle have the maximum thickness at prepupa stage and afterthen gradually they began to degenerate. The epithelium of the follicle which formed by invagination of the peritoneal sheath is differently differentiationed from the peritoneal sheath and it is similar to the adult's from the pupa 2 days. The cell organelles begin to increase in the cytoplasm of the cyst cell enclosed the sperm bundles at pupa 3 hrs. The electron densed granules which observed in the peritoneal sheath and epithelium of the follicle at prepupa seem to be related with fusion of the testis.

• The Korean Journal of Zoology
• /
• v.9 no.2
• /
• pp.21-24
• /
• 1966

1. The differentiation process of the cluster cells of compound eye in wild typed Drosophila melanogaster, born in Heuk San Do, Korea, was observed. 2. The eye disc of Drosophila melanogaster is originated from the frontal sac before hatching. 3. Clusteris bgin to form at the posterior end of the eye disc at the 2 nd instar larval stage, and the completed to differentiate in the eye disc at the 96 hours after hatching . 4. At the pupa stage, the eye cups are formed by clusters. 5. The eye cup begins to elongate and is changed into an ommatidium. 6. All organs of an ommatidium are completed in an omatidium at the old pupa stage(156-160 hours after hatching. )

• Biomedical Science Letters
• /
• v.24 no.2
• /
• pp.125-129
• /
• 2018

Megaselia scalaris, also known as the scuttle fly, has a humpbacked morphology and was categorized as an insect undergoing complete metamorphosis. Megaselia scalaris was reported to be found in diverse environments. Recently, the scuttle fly has been a focus of studies by forensic scientists, geneticists, and developmental biologists. However, detailed research into scuttle fly development is still unclear. Therefore, the current study has been performed to elucidate the development of Megaselia scalaris. The scuttle fly undergoes four distinct stages of development: egg, larva, pupa and adult fly. After mating, the scuttle fly eggs hatch within one day and become larvae. The newly generated larvae go through 1, 2, and 3 instar stages within a period of 5~10 days. The instar stage 1 takes 1~2 days, instar stage 2 takes 1~2 days, and instar stage 3 takes 3~5 days. Depending on the environmental temperature, the pupae stage takes approximately 10~15 days to complete. The pupa stage can be divided into five sub-stages: 1~3 days, 4~6 days, 7~9 days, 10~12 days and 13~15 days. After molting, the newly formed adult scuttle fly can fly after one day. The morphological characteristics of the scuttle fly during each stage of development was detailed within this study.

• Applied Microscopy
• /
• v.15 no.1
• /
• pp.86-100
• /
• 1985

A observation of the ovarian development and oogenesis of Pieris rapae Linne has been carried out during metamorphosis using stereo-microscope, light microscope and electron microscope. The results obtained through this experiment are as follows: 1. The ovarian development and vitellogenesis begin at the 3-day old pupa and the 6-day old pupa respectively, and the adult ovary right after their emergence contains a few mature eggs. 2. The species described above are further observed at six different stages in oogenesis, and the results are summarized as follows. 1) Pieris rapae has polytrophic ovarioles. The cell organelles of the nurse cells are transfered to the oocyte through the ring canal at the early oogenesis. 2) At stage 2, the nuclear envelope of oocyte nucleus is less infolding than that of nurse cell nucleus. In the oocyte cytoplasm a large number of ribosomes are observed. 3) At stage 3 and 4, many micropinocytotic vesicles are observed in the oocyte cytoplasm. These vesicles are fused together to form large proteid yolks. 4) At stage 5, the vitelline membrane is laid down in the intercellular space between the follicle cells and oocyte. 5) At stage 6, the chorion is formed by the follicle cells. 6) A micropyle and a number of aeropyle are observed on the surface of a mature egg.

• The Korean Journal of Zoology
• /
• v.8 no.2
• /
• pp.15-18
• /
• 1965

Fatty acid components of the Chestnut gall wasp (Dryocosmus kuriphilus YASUMATSU) were analyzed by the method of gas chromatogrphy at various developmental stages. 1. The fatty acids identified at each stage are as follows : Larva stage : acetic acid , benzoic acid and capric acid. Prepupa stage : acetic acid, benzoic acid and capric acid. Pupa stage : acetic acid, benzoic acid and capric acid. 2. Through the development of the wasp, there were large amount of acetic acid.