• Journal of the Korean Society of Tobacco Science
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• v.21 no.1
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• pp.17-25
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• 1999

To elucidate the effect of elevated sublethal temperature ($33\pm1^{\circ}C$) on polyamine metabolism and oogenesis, we investigated alterations in the major polyamines and ornithine decarboxylase (ODC) and arginine decarboxylase (ADC), and ovarian development during the pupal-adult development of the tobacco budworm, Helicoverpa assulta. Ovaries ODC activity under the elevated sublethal temperature ($33\pm1^{\circ}C$) were lower than those of the optimal rearing temperature ($25\pm1^{\circ}C$). whereas ovarian ADC activity was consistently higher than the optimal rearing temperature ($25\pm1^{\circ}C$). When the gonads were exposed to the higher temperature, ovarian putrescine showed somewhat suppressed levels throughout development, indicating a relatively high correlationship with the alteration aspects in ODC or ADC activity under elevated sublethal temperature. A somewhat precocious ovary was observed in an early stage of development at $33\pm1^{\circ}C$, but cellular abnormalities occurred in this ovary. The ovary developed under elevated sublethal temperature was observed the inhibitional effect of polyamine metabolism and the abnormal development of ovariole, which seem to be related to the sterility.

• Korean journal of applied entomology
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• v.59 no.4
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• pp.295-301
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• 2020

In this study, we aimed to investigate the changes in the catch rate of Monochamus saltuarius, based on sexual maturation by using aggregation-sex pheromone traps. Ovariole development of caught M. saltuarius females was compared to that of the ones not caught using traps. In a mesh cage set up at the Hongneung experimental forest, we placed a multi-funnel trap with or without an aggregation-sex pheromone lure. M. saltuarius adults, which emerged from pine logs, were grouped in four according to the emergence dates (0, 1, 7, and 10 days after emergence [DAE]). We released beetles into the mesh cage to investigate the catch rate using the traps. In each group, a total of 80 beetles (20 beetles × 4 replications) were tested, making it a total of 320 beetles. Among the four groups, M. saltuarius adults in the 7 DAE group were caught more frequently using the traps, especially with a pheromone lure; the other groups showed a low catch rate. A similar number of female and male beetles were caught using the traps. Regarding ovariole development, all the female adults in the 0 and 1 DAE groups were immature, while those in the other two groups were completely developed. Therefore, aggregation-sex pheromone traps might have a limitation in the prevention of pine wilt disease because of the transmission of pine wood nematode during maturation feeding of newly emerged M. saltuarius adults. However, aggregation-sex pheromone traps can be effective for collecting sexually mature M. saltuarius adults, for the investigation of seasonal occurrence of beetles in forests.

• Journal of Sericultural and Entomological Science
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• v.36 no.1
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• pp.69-75
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• 1994

Through the histological and anatomical investigation of silkworm gonad, N. bombycis infection was found to begin from the peripheral region of ovarial sheath or testicular sheath, then, the pathogens spread to the inner portion. Peroral inoculation with purified spores of N. bombycis to 2nd instar larvae at dosages around 106-8/㎤ of artificial diet resulted in the extremely extended larval survival as long as 15 to 22 days of 4th instar. The growth of ovarioles was confirmed in the 10 to 14 day old larvae, oogonia developed into oocytes and nurse cell against heavy infection of the ovary. Gonads rarely obstructed oogenesis and spermatogenesis in the pupae failed in adult eclosion. Light infection of female hosts effected insignificantly on the ovarial development, however, recorded 100% transmission of the pathogens to the progeny populations. Conclusively, ovarial inflection of silkworm induce transovarial transmission begins around 2~3 day old pupae when ovarioles extruded out to hemocoel, and the infection period thought to be continued until the stage of eggs complete shell formation in the ovariole.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.329-337
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• 2018

To increase the mating rate of Bombus ignitus used as insect pollinator, we investigated the sexual maturity time of B. ignitus. In investigating ovary development such as the number of eggs per ovariole and spermatheca size, the time of sexual maturity of queen was 10 days after eclosion. In case of male, the number of sperm was 246 thousand at immediately after eclosion, and was highest as 480 thousand at 9 days, and tended to show a dramatic decline at 35 days (87 thousand). The more mating time, the less the number of sperm. In consideration of number of sperms, the time of sexual maturity of male was 3-15 days after eclosion. In the sexual maturity time of queen in mating, the queen was not mated at immediately after eclosion, and showed a decrease in 20 days. In terms of the rate of mating and oviposition, the favorable time for mating of queen was 9-20 days. On the other hand, the male showed 3.3% of mating at immediately after ecolosion, showed the highest of 43.3% at 6 days after eclosion, and tended to decrease in 25 days. The sexual maturity time for mating of male was 6-20 days. In summary, our results indicate that sexual maturity time of B. ignitus in reproductive organs and mating is most favorable in 9-12 days after eclosion for queen and 6-9 days for male.

• Korean journal of applied entomology
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• v.60 no.2
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• pp.175-183
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• 2021

As a baseline study of (common name) Locusta migratoria (Orthoptera: Acrididae) to utilize as a food source, we investigated the developmental characteristics of ovaries and eggs. Locusta migratoria had a pair of ovaries and more than 90-104 panoistic ovarioles. The ovary length in the adult stage was longer than it is in the 5th nymph stage. The length on the first day of the adult stage was 2.5-fold longer than the first day of 5^th instar. The ovary length showed a tendency to increase until the 30th day of the adult phase, but decreased from the 35^th day. Ovarioles length was about half of the ovary length, showing a similar tendency to the variation of ovary length. The lengths of the ovaries and the ovarioles increased proportionally to body weight. The matured eggs were identifiable from the 15^th day of the adult stage, and the number was the highest on the 30^th day at 50.6 individuals. Spermatheca size was also affected by the ovary development. The ovaries of L. migratoria were highly matured until the 30th day of adult stage. Weight and size of eggs increased sharply from the 4th day after egg oviposition and remained from the 7th day after spawning. Based on the above results, we found that the ovary of L. migratoria was most developed on the 30th day of adult phase, and 1st nymph is being hatched on the 10th day of the oviposition.