• Korean journal of applied entomology
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• v.49 no.1
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• pp.49-55
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• 2010

Bumblebees are widely used to pollinate crops in greenhouses and fields. Here we firstly developed an apparatus for the oviposition induction of the bumblebee Bombus ignitus using electricity. The apparatus consists of boxes for colony initiation, part of temperature control, part of heat transfer, and moving shelf. The result shows that the rates of oviposition and colony foundation in the newly developed apparatus are respectively 3.9% and 5.2% higher than in the existing apparatus using hot water. More importantly, the newly developed apparatus is 75% cheaper in costs and can more save energy than existing apparatus. These results indicate that the newly developed apparatus could serve as an effective apparatus for the oviposition induction of B. ignitus.

• International Journal of Industrial Entomology and Biomaterials
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• v.26 no.1
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• pp.31-40
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• 2013

Paralytic peptide binding proteins (PP-BP) are 30KP proteins that show similarity to ENF binding proteins. The ENF-BP act as active regulators of ENF peptides. ENF peptides are multifunctional insect cytokines. The comparison of gene expression in diapause induced and non-diapause eggs at different time intervals after oviposition showed an upregulation of PP at 18h as well as PP-BP at 12 and 18h after oviposition along with few other genes. The current study has been taken up to investigate the role of PP as well as PP-BP in diapause induction in polyvoltine silkworms and to study the multigene organization of PP-BP in the Bombyx mori genome. The tissue specific expression analysis revealed that, PP-BP is highly expressed in fat body followed by egg and brain while no expression was observed in midgut. The expression levels of PP and PP-BP in diapause and non-diapause eggs from 0h to 48h after oviposition, validated through realtime PCR revealed that PP is highly expressed at 18 and 24h while PP-BP expression is higher at 12 and 18h time intervals suggesting their possible role in diapause induction. The whole genome survey of the PP-BP paralogous sequences revealed a total of 46 B. mori PP-BP homologs that are classified into 3 categories viz., ENF-BP, Typical 30KPs and serine/threonine rich 30KPs. These paralogous sequences are distributed on chromosomes 7, 20, 22 and 24, all 30KP and S/T rich 30KP proteins are present in the same locus of chromosome 20.

• International Journal of Industrial Entomology and Biomaterials
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• v.28 no.2
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• pp.51-57
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• 2014

Bumblebees are important pollinators of crops and wildflowers. The Korean native bumblebee, Bombus ignitus, undergoes one generation per year, and induction of artificial hibernation is essential for year-round rearing of the bumblebee. Keeping queens under cold treatment conditions for several mo is an effective method for terminating their diapause and promoting colony development. In the present study, we investigated how the timing and duration of chilling affect the artificial hibernation of B. ignitus queens. In the timing assessment, cold treatment was instituted at 12 d, 40 d, or 100 d after eclosion under a constant temperature of $5^{\circ}C$ and 80% humidity. The queens that entered cold treatment at 12 d after emergence evidenced the highest survival rates: 86.7% at two mo, 73.3% at three mo, and 46.4% at 4 mo. Survival rates were reduced under storage conditions at 12 d, 40 d, and 100 d after emergence. When queens were subjected to chilling at 8 d, 12 d, or 16 d after eclosion with constant 80% humidity, the queens stored at 12 d after eclosion exhibited the highest survival rates, which were 84.6 at one mo, 25.0% at two mo, and 7.9% at three mo. In regards to the duration of the cold period, the queens that hibernated for at least two mo evidenced optimal colony development rates. The rates of oviposition, colony foundation, and progeny-queen production of queens hibernated for two mo were 60.0%, 30.0%, and 13.3%, respectively. These values were 6.0 to 13.3 times higher than those in the queens that hibernated for 15 d. Therefore, a cold period of at least 2 mo applied 12 d after emergence were found to be the most favorable conditions for diapause break in B. ignitus queens.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.1
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• pp.173-181
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• 1992

Duck is an important domestic animal, especially in Asia. Eighty five percent of ducks in the world are kept in Asia, especially in the East and South Asia regions. The ancestor of domesticated ducks was mallard (Anas platylhynchos), which are still migrating between north and southern parts in Eurasia. Ducks have been domesticated in China for at least 3000 years ago. Phylogenetic studies on ducks, employing electrophoresis of blood proteins, indicate a marked difference of genetic constitution between duck breeds in southeast Asia and those in northeast Asia. Duck embryonic ovary is much more active in secretion of sex steroid hormones especially estradiol than the embryonic testes. Estradiol secreted by the embryonic left ovary has an important role in female sexual differentiation in ducks. In the female ducks, plasma LH, estradiol and testosterone levels increase and reach peaks shortly before the first egg, while progesterone level reach a peak shortly after the first egg. In laying ducks oviposition mostly occurs in the last 3 hr of darkness and first hr of light ranging 02:00-06:00 under 14 hr light (05:00-19:00) and 10 hr darkness photoperiodic condition. Measurements of plasma hormone levels reveal that onset of darkness is a major signal for LH release from the pituitary and the subsequent release of progesterone from ovary, and for induction of ovulation in the female duck.

• Korean journal of applied entomology
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• v.23 no.1 s.58
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• pp.42-48
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• 1984

The developments of overwintering larvae of the peach fruit moth, Carposina niponensis Walsingham, were studied in Suweon. Among fully grown larvae leaving from apple fruit, the earliest diapause larva was observed late July, about $50\%-diapause$ in middle August and $100\%-diapause$ in early September. Induction of the diapause seemed to have relationships with the time of oviposition: the incidents of the diapause started with the larvae grown from the eggs which had been laid in late June or late July depending on the prevailing weather condition. The termination of the diapause seemed to be in early December, and almost all of the larvae incubated after January were pupated. For the breakage of the diapause, it required chilling period more than one month, and the most effective temperature seemed to be $5\~10^{\circ}C$, while the temperature lower than $0^{\circ}C$ seemed to be inhibitory, if not at all. The overwintered larvae started to pupate in middle May, and the developments of the over-wintered larvae were affected by the temperature as well as the moisture contents of soil in the spring. The dry condition of soil increased the mortality of the developing larvae.