• International Journal of Industrial Entomology and Biomaterials
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• v.20 no.2
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• pp.93-98
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• 2010

Bumblebees are widely used to pollinate various crops, especially tomato, in greenhouses and fields. An artificial hibernation is essential for year-round rearing of the bumblebee, which passes through one generation per year. Here, we investigated whether a chilling temperature and humidity affect artificial hibernation of the bumblebee queen Bombus terrestris. In chilling temperature regimes of $0^{\circ}C$, $2.5^{\circ}C$, $5^{\circ}C$, $7.5^{\circ}C$ or $12.5^{\circ}C$ under constant humidity >70%, the queens stored at $2.5^{\circ}C$ exhibited the highest rate of survival, which was 74.0% at one month, 67.0% at two months, 60.0% at three months, 46.0% at 4 months, 33.0% at 5 months, and 24.0% at 6 months. Rates of survival decreased at the following temperatures: $0^{\circ}C$, $5^{\circ}C$, $7.5^{\circ}C$ and $12.5^{\circ}C$. Colony developmental characteristics after diapause were 1.2- to 1.5-fold higher than those of queens stored at $5^{\circ}C$. In terms of chilling humidity, the queens hibernated at 70% under $2.5^{\circ}C$ exhibited the highest rate of survival, which was $93.3{\pm}3.4%$ at one month, $83.3{\pm}0.0%$ at two months, $76.7{\pm}0.0%$ at 3 months and $36.7{\pm}12.1%$ at 5 months. The rates of oviposition, colony foundation and progeny-queen production of queens hibernated at 70% were 80.8%, 30.8% and 30.8%, respectively. These values correspond to 1.7- to 3.3-fold increases in comparison to queens stored at 50% humidity. Therefore, $2.5^{\circ}C$ and 70% R.H. were the favorable chilling temperature and humidity conditions for diapause break of B. terrestris queens.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.383-392
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• 2015

We investigated the induction of pupal diapause and number of generation for H. armigera using outdoor rearing and sex pheromone trapping in Suwon, Korea. Over-wintering pupae were induced when neonate larvae were reared in the outdoors from late Aug. to early Oct. in 2013 and 2014. H. armigera adults emerged from late May to early Jun. for 2013 colonies and from late May to late Jun. for 2014 colonies. The colonies placed after mid September produced only diapause pupae, to show environmental conditions that day-lengths on the rearing start date were 11 h 49 min~12 h 24 min, and mean temperatures before pupation were $14.8{\sim}20.7^{\circ}C$. Summer diapause was not observed in all colonies. The peak occurrence of H. armigera adults from sex pheromone trap in Suwon and Hwaseong were pooled and showed four generations (1st: from late Apr. to mid Jun., 2nd: from mid Jun. to late Jul., 3rd: from mid Jul. to late Aug., 4th: from late Aug. to mid Oct.). A degree-day model for development of H. armigera developed by Mironidis and Savopoulou-Soultani (2008) was used to validate the number of generation from field observations using pheromone traps. The 3rd and over-wintering generations were mainly overlapped. It was decided that H. armigera has one over-wintering and three complete generations in a year, and diapause is induced from offsprings of the 3rd and 4th generations adults. It is expected that larvae of the 1st and 2nd generations give a damage to ear zone in maize fields in which have been planted during April.

• Korean journal of applied entomology
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• v.43 no.3 s.136
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• pp.201-209
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• 2004

Overwintering ecology of the peach pyralid moth, Dichocrosis punctiferalis Guenee (Lepidoptera: Pyralidae) was studied in laboratory and in a chestnut orchard in 2001/2002 winter and 2003 spring. All twenty-four female and fourteen male moths were fruit-feeding type which were emerged from the larvae collected at the same chestnut orchard in 2003 winter. Periodical thermal treatment of overwintering larvae at $25^{\circ}C$ revealed that diapause termination of the larval population started from the end of January and was completed until April 20 in southern region of Korea. Pupation of diapause-terminated larvae started from early May and reached to $100\%$ at June 3 in chestnut orchard. Days to pupation of female larvae after diapause termination were 12.5, 8.9, and 7.5 at $20^{\circ}C,\;25^{\circ}C$, and $30^{\circ}C$, respectively. Those of male larvae were similar to those of females. Pupal periods of female were 14.7, 11.8, and 9.0 days at the three temperatures. Moths of the overwintered generation emerged from May 20 to June 28, and reached to $50\%$ emergence on June 8 to 9 under emergence cage. Attraction of the male moths of overwintered generation to sex pheromone traps showed that the date of $50\%$ catches to the traps were June 17, when data from 3 southern regions of Korea were pooled.

• 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.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2004.05a
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• pp.134-134
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• 2004

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2002.05a
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• pp.143-143
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• 2002

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2002.11a
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• pp.110-110
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• 2002

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2000.05a
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• pp.50-50
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• 2000

• Korean journal of applied entomology
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• v.49 no.3
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• pp.205-210
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• 2010

The bean bug, Riptortus pedestris (=clavatus) Fabricius (Hemiptera: Alydidae) is a serious pest of soybean in many countries. It enters a reproductive diapause in the winter by short day length (<13.5 h.) in Korea and Japan. The combined effects of temperatures ($25^{\circ}C$ and $8^{\circ}C$) and day lengths (10L:14D and 14L:10D) upon the termination of the male's diapause were studied. The combinations are (1) HTLD = $25^{\circ}C$, 14L:10D treatment for 1, 2, 3 weeks and 30 days; (2) HTSD = $25^{\circ}C$, 10L:14D treatment for 1, 2, and 3 weeks; (3) LTLD$\rightarrow$HTLD = $8^{\circ}C$, 14L:10D treatment for 1, 2, and 3 weeks followed by HTLD treatment; (4) LTSD$\rightarrow$HTLD = $8^{\circ}C$, 10L:14D treatment for 1, 2, and 3 weeks followed by HTLD. The amount of aggregation pheromone components secreted was adopted as the criteria for diapause termination in males. Males did not secrete aggregation pheromone under HTSD conditions. However, the males treated with HTLD for more than 21 days secreted significantly higher amounts of aggregation components, (E)-2-hexenyl (Z)-3-hexenoate and (E)-2-hexenyl (E)-2-hexenoate, compared to the control or HTSD treatments. The three components of the aggregation pheromone were secreted by the 14%, 29%, and 100% males treated with HTLD for 7 days, respectively. However more than 83% of the HTLD-treated males secreted all three components by the $30^{th}$ day under the treatment. In comparison, the pheromone amounts secreted by the males treated with LTLD$\rightarrow$HTLD or LTSD$\rightarrow$HTLD were equal or less than those secreted by males with continuous HTLD treatment.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2005.04a
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• pp.72-72
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• 2005