• Korean journal of applied entomology
• /
• v.57 no.4
• /
• pp.329-337
• /
• 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
• /
• v.48 no.2
• /
• pp.189-195
• /
• 2009

This study was performed to investigate the emergence timing and daily emergence from the different tree species logs (Korean white pine, Pine, and Japanese larch) at Cheongwon, Chungcheongbuk-do from 2006 to 2008. Pine sawyer adults began to emerge on early May (2${\sim}$10th day) and finished on mid-June (4${\sim}$20th day) in the Korean white pine and pine logs. However, pine sawyer adults began to emerge on mid-May (13th day) and finished late May (27th day) in Japanese larch logs, Japanese larch logs shows shorter emergence timing of pine sawyer adult compare to those of other two tree species. Emergence timing shows no difference between males and females. Sex ratios of emerged adult in 2007 were 0.55 from Korean white pine, 0.46 from Pine, and 0.59 from Japanese larch; it shows no difference among tree species. Female and male adults emerged throughout 24 hrs; 22.8% of the total adults emerged from 12${\sim}$14:00 (22.8%) and adults emerged lowest from 06${\sim}$08:00. Of the adults emerged from the logs, 98.9% was univoltine and the rest was biennial which emerged next year.

• Journal of Korean Society of Forest Science
• /
• v.26 no.1
• /
• pp.43-47
• /
• 1975

Forecasting of emergence period of the pine gall midge (Thecodiplosis japonensis U. et I.) is important for the chemical control of the pest. In order to determine the phenosignal of the emergence period of the pine gall midge, the flowering time of black locust (Robinia pseudoacacia L.) at Seoul, Gwangnug, Jounju and Gyungju districts in Korea was investigated. 1. The emergence period of the pine gall midge lasted from end of May until end of June. The emergence of the pine gall midge coincided with the beginning of flowering of black locus at every districts in Korea. 2. The peak of emergence of the pine gall midge lasted from the full blooming period until the end of the flowering period of the black locust. 3. The period of adult emergence of pine gall midge was also found to be associated with the full blooming period of Viburnum sargentii (Caprifeliaceae). Rosa mulliflora (Reseaceae) and Iris ensata (Iridaceae) at Seoul in Korea.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.9 no.4
• /
• pp.217-227
• /
• 2007

The western cherry fruit fly, Rhagoletis indifferens Curran (Diptera:Tephritidae), is the most important pest of cultivated cherries in the Pacific Northwest area of the United States, being widely distributed throughout Oregon, Washington, Montana, Utah, Idaho, Colorado and parts of Nevada. The control of R. indifferens has been based on calendar sprays after its first emergence because of their zero tolerance for quarantine. Therefore, a good prediction model is needed for the spray timing. This study was conducted to obtain the empirical population dynamic information of R. indifferens after overwintering in the major cherry growing area of the Pacific Northwest of the United States, where the information is critically needed to develop and validate the prediction model of the fruit fly. Adult fly populations were monitored by using yellow sticky and emergence traps. Larvae growth and density in fruits were observed by fruit sampling and the pupal growth and density were monitored by pupal collection traps. The first adult was emerged around mid May and a large number of adults were caught in early June. A fruit had more than one larva from mid June to early July. A large number of pupae were caught in early July. The pupae were collected in various period of time to determine the effect of pupation timing and the soil moisture content during the winter. A series of population density data collected in each of the developmental stage were analyzed and organized to provide more reliable validation information for the population dynamic models.

• Korean journal of applied entomology
• /
• v.42 no.4
• /
• pp.307-313
• /
• 2003

Japanese pine sawyer, Monochamus alternatus, is a primary vector of pinewood nematode, Bursaphelenchus xylophilus in Korea. Emergence characteristics of the adults were studied in Jinju, Korea using dead pine logs in which the larvae of the sawyer overwintered from 1999 to 2002. Emergence data showed that the adults began to emerge out of the logs in sunny place from May the 15th in average of the four years. Cumulative emergence ratio (CER) reached at 50% at mid-June, and the emergence terminated by early or late July depending on years. In shady place, however,50% CER was reached 17 days later than in sunny place. The 50％ CER of males reached 1 to 4 days earlier than that of females depending on years. Of the adults emerged from the logs collected from February to April in 2001, 97.6％ was univoltine, and the rest was biennial which emerged from May to July of the next year. Female and male adults emerged throughout 24 hours; 32.3% of the total adults emerged from 8 to 12 a.m. It took 68.0 seconds for the adults to escape from pine logs.

• Korean journal of applied entomology
• /
• v.52 no.4
• /
• pp.427-430
• /
• 2013

Recently, climate change scenarios were substituted by the Special Report on Emission Scenarios (SRES) for Representative Concentration Pathway (RCP). Using the RCP scenario, the World Meteorological Organization (WMO) produced new climate change scenarios. Further, the National Institute of Meteorological Research (NIMR) of Korea produced new climate change scenarios for the Korean Peninsula. In this study, emergence time of small brown planthopper (SBPH), Laodelphax striatellus and the number of generations a year were estimated during climatic normal year (1981-2010) with previous studies and they were predicted during 2050s (2045-2054) and 2090s (2085-2094) by means of RCP8.5 climate change scenario. In comparison with $176.0{\pm}0.97$ Julian data in the climatic normal year, the emergence time of overwintering SBPH was predicted to be $13.2{\pm}0.18$ days ($162.8{\pm}0.91$ Julian date) earlier in 2050s and $32.1{\pm}0.61$ days ($143.9{\pm}1.08$ Julian date) earlier in 2090s. The SBPH was expected to produce an additional $2.0{\pm}0.02$ generations in 2050s and $5.2{\pm}0.06$ generations in 2090s.

• Korean journal of applied entomology
• /
• v.47 no.1
• /
• pp.9-15
• /
• 2008

This study was conducted to investigate the seasonal occurrence of chestnut weevil, Curculio sikkimensis. The chestnuts infected by the weevils were collected from Gongju, Buyeo, and Cheongyang in Chungnam Province, Republic of Korea. Investigation was focus on the escape period of chestnut weevil larvae from the fruits, invading time and vertical distribution in soil, survival rates of larvae during overwintering, emergence period, emergence rate, and sex ratio and longevity of adults. For precocious species, larvae escaped the chestnut from the mid-September to the early-October, middle species and slow species, were escaped from the late-September to the mid-October and from the early-October to the mid-November. After escaping from the chestnut fruits all of the larvae burrowed into the soil within 35 minutes. Overwintering larvae inhabited in the range of $0{\sim}48cm$ from the soil surface and highly distributed in the range of $18{\sim}36cm$. The 74.1 % of wintering chamber were distributed within $18{\sim}36cm$ from the surface. Survival rates observed were 38.0% in 1st year, 16.0% in 2nd years, and 2% in 3rd years, respectively. Seasonal occurrence period of C. sikkimensis was from the early-Aug. to early-Oct. and the optimal occurrence period was the early and mid-Sept. Emergence rate decreased to 8.4% in 1st year, 3.6% in 2nd years, and 0.8% in 3rd years, respectively. Sex ratio was showed in the range of 0.51-0.55. It is female biased ratio. Longevity of adults was 9.9 days for female and 8.9 days for male.

• Korean journal of applied entomology
• /
• v.30 no.4
• /
• pp.249-257
• /
• 1991

Chronological changes in the occurrence pattern of the striped rice borer(SRB), Chilo suppressalis Walker, were investigated by analyzing the data collected by 33 light traps of the countrywide monitoring units during the period of 1968-1989. And also relation of incidences between larval and adult populations, emergence time and percent emergence of overwintered larvae were observed in relation to the time of different rice transplantations. Spring moths of SRB in 1985-'89 generally emerged earlier than in 1968-'72 : 30 days earlier at Kwangju, 20 -25 days earlier at Sangju and Naju, 10-15 days earlier at Uljin, Jinju, Goyang, Milyang, Kimhae, etc., 5 days earlier at Suweon, Jinchun, Daejeon, Namweon, Haenam, etc. There was no change in the time of spring moth emergance at Weonseong, Chungju, Seosan, Yongju, and Nonsan. Summer moths of SRB in 1985- '89 also emerged earlier than 1968- '72: 20 days earlier at Uljin, 15 days earlier at Chungju, Yeongdug, and Habchun, 5-10 days earlier at the other areas except Yeongju. There was an overall countrywide decrease in the population of the 1st generation of SRB during the last two decades. The population of the 2nd generation also decreased in 19 areas during the same period, but increased in 14 areas including over 3-fold increases in Kwangju, Naju and Daegu, and double increase in Jinju, Milyang and Gongju. The higher larval population density of 1st genration was taken place in the earlier transplanted fields, whereas the population of 2nd generation were higher at mid-season transplanted (May 30), followed by May 15, June 15, and April 30. The peak of larval population appeared generally 15 days after moth peak in 1st generation, and 10 days after moth-peak in 2nd generation. The earlier transplanted fields were the higher percent damage due to 1st off-springs of spring moths, whereas the fields transplanted in mid-season were higher damage due to 2nd off-springs of summer moths. Average body weights of SRB larvae before overwintering were 65.6 mg, 61.2 mg, and 55.5 mg in early, mid-season, and late transplantations, respectively. In field cage experiments, emergence rate of the overwintered larvae ranged from 28.3-39.8%. In other words, body weights of overwintering larvae were heavier in fields by earlier transplantation, and heavier larvae showed higher percentage of adult emergence. The period from overwintered larvae to adult emergence was longer in the fields of the later transplantations; namely, 44, 49, and 51 days for early, mid-season, and late transplantations, respectively.

• Korean Journal of Plant Resources
• /
• v.19 no.5
• /
• pp.598-601
• /
• 2006

In order to prevent chestnut from damaged by the chestnut gall wasp, Dryocosmus kuriphilus, a sprinkler system was installed on the chestnut orchard. Such a test was conducted at Sanchung-gun, Kyeongnam province, Korea in 2003 and 2004. Insecticide of carbaryl 50% WP, x1,500 was sprayed at every day and two-day intervals during the period of D. kuriphilus adult occurrence by sprinkler system. The chestnut gall wasps generally emerged for about 35 days from the middle June to the middle July, and peak emergence was 5 days of early July. Crown application of carbaryl by sprinkler system was found to be highly effective for control of the chestnut gall wasp. Gall formation rate of chestnut were 3.0 and 12.8% on average with crown insecticide spraying at every day and two-day intervals, while 82.9% when not treated. Control effectiveness of this insecticide spraying was 96.4% and 84.6%, respectively.

• Korean journal of applied entomology
• /
• v.23 no.2 s.59
• /
• pp.132-136
• /
• 1984

This study was conducted to investigate the bionomics of Curculio sikkimensis in Chonnam province from 1981 to 1983. Damage rates of the chestunt were $26.4\%$ in Damyang, $21.1\%$ in Gwangyang, and $12.9\%$ in Seungju. Adults occurred from the mid-July to the mid-September and showed peak from the mid-August to the early-September. Larvae escaped the chestnut from the early-October to the early-November. Overwintering larvae emerged $3.3\%$ in the first year, $22.78\%$ in the second year and continously overwintered $1.67\%$ in the third year. Larvae showed the highest distribution at $1.67\%$ of soil depth during the overwintering. Mortality of overwintering larvae and course of time showed the linearly correlation. Period of each stage was 5.9 days for egg and 17.17 days for pupa. Adult longevity was 9.10 days for female and 7.03 days for male.