• Korean journal of applied entomology
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• v.41 no.3
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• pp.177-181
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• 2002

This study investigated seasonal occurrence of Frankliniella occidentalis and its damage on chrysanthemum from 1999 to 2000. F. occidentalis adults were attracted to yellow sticky traps from early April to harvesting time in the field. The highest densities were observed from late April to mid-June in spring culture and from mid-August (just after transplanting) to early September in autumn culture respectively. Seasonal fluctuation in a PVC green house was similar to that in the field. Number of insects per flower were higher in the green house than that in the field. Leaf damages due to the insects were observed from mid-May and increased as chrysanthemum grows (R$^2$ = 0.9200-0.9887$\^$**/, p> 0.01).

• Korean journal of applied entomology
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• v.43 no.4 s.137
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• pp.291-296
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• 2004

Overwintering sites and Seasonal occurrence of various growth stage of the rice black bug, Scotinophara lurida BURMEISTER were studied at the rice paddy field in Chungbuk area, from 1999 to 2001. Attraction by light trap from overwintering site of overwintering adults occurred from early June to mid July and its peak was shown on late June. Eggs were oviposited from early July to early August and its peak appeared in late July. Nymphs were observed from mid July to late September with its peak on mid August. The newly eclosed rice black bugs were found in late August and its peak on mid September. The rice black bug overwintered as adult at mountain foot, banks, and rice paddy levee.

• Korean journal of applied entomology
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• v.36 no.3
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• pp.243-248
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• 1997

The local distribution and life cycle of Mahasma aurea (Butler) attacking Ginkgo biloba L. in Seoul and Incheon areas were studied during 1994 - 1996. The species had one generation a year. The overwintered 3rd larvae begin to feed on buds of the host plant from mid May and then on the leaves until early June. Newly hatched larvae mostly infested the leaves from mid August to late September. Pupation took place from mid June to early July, and the moths emerged in early July.

• The Korean Journal of Ecology
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• v.22 no.5
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• pp.299-303
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• 1999

Studies were conducted in Mt. Namsan, Seoul, during the summer of 1997 and 1998 using racemic disparlure to determine seasonal occurrence and circadian activity in male gypsy moth, and size of egg mass and wing length of male moth. Male gypsy moths occurred from middle part of July until middle part of August and peaked in late part of July. Circadian activity of male moths initiated from 12: 00h and continued until 21: 00h, and the peak time was between 14: 00h and 17: 00h. Mean number of moths captured per trap in 1997 was larger than that in 1998, however, eggs per mass, egg size and wing length were not significantly different between the two years, 1997 and 1998.

• Journal of Korean Society of Forest Science
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• v.12 no.1
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• pp.59-63
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• 1971

In the light of the fact that Cryptorrhynchus lapathy Linne (Coleoptera: Cur-culionidae) is an important past of poplar in korea the Bionomics of the insect were studied to get some basic informations for controlling the insect. The results obtaind are as follows; 1. The poplar and willow borer has one generation in a year overwintering with egg. 2. The pupation stage was from the middle Julne to the middle July. 3. The adult appears from the early July to the middle August. 4. The average length of body of adult was about 8.5cm with female, 7.9cm with male and the length of pupa was about 11.3cm. 5. The average longevities of adults were about 30 days with mate and 40 days with female. 6. The length of damage hole were about 10.3cm. 7. The egg-laying period was from July to August.

• Journal of Korean Society of Forest Science
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• v.84 no.1
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• pp.87-96
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• 1995

We examined the effects of seed treatment on field germination rate and seedling growth for four woody species, Euonymus alatus, Thea sinensis, Zanthoxylum piperitum, Nandina domestia which are economically useful in Korea. The seeds of each species were purified carefully after collection during Oct. and Nov.. E. alatus, T. sinensis, and Z. piperitum were sowed in the experimental field after stored in open ground with treatment of Pon-Pon. $H_2O_2$, $GA_3$, scarification. and N. domestica was sowed in container within green house after treatment of three different periods(7, 15, 21days) in growth chamber(4, 25, $32^{\circ}C$). Germination rate and seedling growth were measured in mid-Oct.. In E. alatus germination rate was higher in storaging in open ground after soaking in $GA_3$(67.1%) than in only storaging in open ground(18.4%). But the rate in T. sinensis showed no differences between storage in open ground after treatment of $GA_3$, and scarification, and only storage in open ground, Germination rate of Z. piperitum was much higher in storaging in open ground after treatment of Pon-Pon(80.3%) than in only storaging in open ground(12.4%). In N. domestica. seeds stored for 7 days at $32^{\circ}C$ were germinated faster than those stored for 7 days at $4^{\circ}C$, and germination rate of the former was also higher than that of the latter. Peak Times of seed germination in field were order of E. alatus (32 days). Z. piperitum (49 days). T. sinensis (83 days), N. domestica (87 days). The growth of seedling germinated in field showed a good result because of early germination following the effect of seed treatment. The periods of highest growth performances of the seedlings were 72 days in late Jun.-mid Jul. in E. alatus. 59 days in late Jun.- mid Jul. in Z. Piperitum, and 45 days in mid Aug.- mid Sep. in T. sinensis.

• Asian Journal of Turfgrass Science
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• v.26 no.2
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• pp.83-88
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• 2012

When perennial ryegrass was overseeded in bermudagrass fairway, shoot density of perennial ryegrass was gradually increased to $88,000/m^2$ at the end of May, however dramatically decreased to 0 in September over the rainy season. On the other hand, that of bermudagrass increased from $2,000/m^2$ in March to $20,000/m^2$ in early June, and then decreased to $4,000/m^2$ at the end of July, after the rainy season, rapidly increased to $50,000/m^2$ in early September. Overseeding bermudagrass fairway with perennial ryegrass was maintained a good quality from mid-April to mid-June and decreased the quality over the rainy season from late June to July, and then turf quality was decrease to the worst level at the end of July. After the rainy season fairway quality was improved gradually and was the highest-level during September and early October. Trifloxysulfuron-sodium was treated to minimize the deterioration in turf quality due to early bermudgrass transition time in spring. Consequently, transition was started in mid-May and shoot density of bermudagrass treated by trifloxysulfuron-sodium was $70,000/m^2$ in mid-June. Even in the rainy season it was sustained as $30,000/m^2$, approximately three times higher than that of untreated overseeding fairway.

• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.275-282
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• 2006

Insect pests attacking the leaf of lettuce (Lactuca sativa) were surveyed in environmentally frendly leaf-lettuce-greenhouses in Hwaseong, Namyangju, and Suwon from 2003 to 2004. Sixteen insect species of eleven families in eight orders were collected in greenhouses. Among them, Acyrthosiphon solani, Frankliniella occidentalis, and Autographa nigrisigna were the most serious pest species because of their damage ratio was over 30%. Population of Acyrthosiphon solani showed the highest peak one or two times between mid-April and early June in both the second and the third cropping period. Frankliniella occidentalis reached the highest peak one or two times, the first peak between mid-June and the late July, and the second peak between the mid-August and the mid-October.Autographa nigrisigna reached the highest peak one or times between early June and late July and in the mid-August to late October. The highest peak occurrence of A. solami was observed in early June as many as 4,836 nymphs and adults per 100 leaves. And for F. occidentalis it was in early July occurring 437 larvae and adults per 100 leaves, for A. nigrisigna in early October occurring 42 larvae per 100 leaves. The density of F. occidentalis and its damage as well was greater in soil culture than in hydroponic culture, but in case of both A. solani and A. nigrisigna no such difference between cropping systems was found.

• Korean Journal of Plant Taxonomy
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• v.44 no.4
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• pp.281-287
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• 2014

The present study was conducted to understand the growth pattern, pollinators and their frequency of visits of Euphorbia helioscopia population which is located at Tongyoung areas in Korea. The vegetative parts of the species grow early in March, and flowering begins in the middle of the month, and pollination was completed at the mid of April. As a typical form of early spring type, the fruits of E. helioscopia were matured between early in April and May, and the upper parts of plants were disappeared between May and June. During the blooming season about 11 insects species which belong to Diptera, Hymenoptera, Coleoptera and Heteroptera were the most common groups found on this plants. Among them the species of Diptera are the most dominant pollinators for E. helioscopia which is concordant to previous reports in Euphorbia species. Despite of significant numbers of insect visitors in Euphorbia species being reported, E. helioscopia attracts only 11 insect species in study areas, and the paucity of species probably associates with the insect fauna in Tongyoung areas or typical patterns of early spring bloomer of Euphorbias. We observed majority of Diptera species to visit in the morning, and the frequency of visit decreased in the afternoon. Thus, it suggests that the visiting activity of Diptera species is not associated with the temperature increase which was reported in Euphorbia species. However, the number of the cyathium during the blooming season is likely to be related to the frequency of visit of pollinators in E. helioscopia.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.3
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• pp.211-215
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• 2002

This study was carried out to find out the optimum harvesting time on the basis of physiological characteristics, yield and commercial value in four years old ginseng. For this purpose, the changes of agronomic growth characteristics of the aerial and underground parts with different growing stages were examined with fourth year ginseng. The leaf growth was dramatically increased from the mid-April (shooting stage) to the mid-May (flowering stage), and the growth was nearly completed by the mid-May, but the stem growth continued by the mid-August. The weight of fresh root decreased from the April (20.7g) to the June (18.2g), but increased from the June to the October(45. 1g). The yield of fresh root per "Kan" was 1.5 kg, 1.2kg and 1.3kg at the April, the May and the June, respectively, thereafter continually increased to 2.9 kg of the October, which showing the maximum yield. In conclusion, the ginseng root was generally harvested from the September to the October at farm-house, but it had better be harvested after the mid-October rather than from September to October considering the weight of dry root and the yield of fresh ginseng.h ginseng.