• Journal of Korean Society of Forest Science
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• v.59 no.1
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• pp.31-36
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• 1983

Flowering time of Pinus rigida Mill and Pinus taeda L, in an $F_1$-hybrid seed orchard was investigated for five years from 1971 through 1975. The two tree species flowered during late April to early May at the observation site, Flowering patterns of the two species of different sex of the same species changed yearly during the five observation years. Floral development of the two species appeared to depend largely on temperature factor during the period of the initiation of floral organs up to flowering provided that other environmental factors are normal. Six-days difference in flowing time between female inflorescence of pitch (flower later) and male inflorescence of loblolly (flower earlier) pines effectively isolated the two species reproductively on population levels. Not all of selected trees of the two species for their synchronized flowering appeared to be useful as parental trees for the establishment of $F_1$-hybrid seed orchards. With the result from this investigation the author suggested to use a modified simple recurrent selection method for pitch-loblolly hybrid pine breeding.

• Korean journal of applied entomology
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• v.40 no.3
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• pp.219-226
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• 2001

To identity the composition and ratio of the sex pheromone in the asiatic leafroller, Archippus breviplicanus (Walsingham), which is a major pest on apple leaves, and to develop a monitoring system using this sex pheromone, abdominal tips of their virgin female during the calling period were extracted and analysed. The GC/GC-MS analysis revealed the following three compounds; (E)11-tetradecenyl acetate (E11-14: Ac), (Z)11-tetradecenyl acetate (Z11-14: Ac), and tetradecyl acetate(14: Ac) with the ratio of 56:22:22. Electroantennogram (EAG) assay was also conducted to examine biological activity of the components. The three components evoked significantly higher responses than hexane or air but there was no significant differences between the mixtures made by components. Field trapping experiments for determining the optimum blend, seasonal fluctuation and the optimum amount for male attracting were carried out over 4 years from 1997 to 2000. Although male moths were attracted to 8:2 and 7:3 between E11-14: Ac and Z11-14: Ac, their 7:3 blend was found to be the most effective. Archippus breviplicanus appears to occur three times a year in Korea. The optimum amount for monitoring was found to be 1mg per trap. 14: Ac, the third component, did not show synergistic effect on male moth attraction.

• Korean journal of applied entomology
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• v.17 no.1 s.34
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• pp.41-47
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• 1978

Pheromones of several insect species were evaluated in a screening program in terms of their usefulness in pest forecasting and control in Korea. Species included striped rite borer (Chilo suppressalis) and tortricid moths, which attack deciduous fruit, and colding moth. The pheromone of striped rice borer was supplied through the courtesy of the Tropical Products Institute, London. Pheromones of other species were obtained from Cornell University and the Zoecon Corporation of Palo Alto, California. 'rho results of this experiment were as follows: 1. Live traps containing virgin striped rice borer female moths were more effective in attracting male moths than were the pheromone traps. 2. Since the effectiveness of the striped rice borer pheromone decreased dramatically with time, it was difficult to estimate the peak tine of the borer emergence. 3. The primary species trapped in deciduous fruit orchards was the oriental fruit moth, Grapholitha molesta. The traps were baited with the phermones, OFM and LAW. 4. Several moth species were trapped with OBLR. RBLR. SPAR and ArcM phermones but few were trapped with the remaining eight tortricid pheromones. 5. The following tortricid pheromones might be useful for forecasting the species given: OFM, LAW : Grapholitha molesta OBLR : Archips breviprecanus OBLH, RBLR, ArcM : Archippus coreensis Archips fuscocupreanus Hoshinoa longicellana SPAR, TBM ; Phyroderces sp.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.369-374
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• 2015

Grapholita molesta (GM) has been considered as a major problem to apple and peach orchards. Mating disrupters have been applied to control the pest over the world as an Integrated Pest Management [IPM] tool. Various types of dispensers releasing mating disrupters have been developed with different formulation of wax, polyethylene tube and aerosol. In this study, the dispensers that were composed of ester waxes and polypropylene (PP) film were used as dispenser materials to analyze release pattern of GM pheromone compared with paraffin wax and polyethylene (PE) film. The release pattern in PP film group was consistent with time while PE film group irregular. Based on these results, Japan wax_PP film dispenser (Japan_PP) was manufactured and showed the mating disruption effect of 98% during 5months in peach orchard.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.351-357
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• 2015

The two-spotted spider mite Tetranychus urticae Koch, overwinters in apple culture areas of apple orchards. The mite overwinters in various places on the apple trees, usually in groups of 5-15 females. Overwintering females were mostly found in bark crevices with the hibernation cocoons of the oriental fruit moth, Grapholita molesta Busck. They were also found in small crevices of the bark, and in pedicels left after fruit harvesting. Furthermore, overwintering females were found on rough bark at the bases of buds and spurs, on small limbs and twigs, and in limb crevices and forks. Empty scales of dead diaspidids and coccids, as well as cocoons of lacewings and mummies of parasitized aphids sporadically found on trees, were found to be less common overwintering sites for females of the two-spotted spider mite. In two successive years, the mortality of overwintering females was very high, reaching approximately 72 and 80%. This could be due to the low temperature of winter season in Korea and the low cold tolerance of the mite.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.295-301
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• 2015

We investigated mycophagous ladybird, Illeis koebelei from 12 species of plants infected with powdery mildew in Gyeonggi-do, Korea. The pear tree, Pyrus ussuriensis var. macrostipes (Nakai), was most preferred by I. koebelei. This species was found from early July to early November in pear orchards. There was no entomophagous trace in the gut of I. koebelei without powdery mildew spores in a microscope. All stages except egg and pupa are obligate mycophagous, and the feeding potential is ranked as follows: fourth instar, adults, third instar, second instar, and first instar. Feeding amounts of each stage of I. koebelei were 45.6, 144.4, 372.2, 628.1, and $473.7mm^2$ of cucumber powdery mildew per day. Fourth instar larvae showed highest consumption of cucumber powdery mildew. Developmental periods of four larval instars and adults feeding cucumber powdery mildew were 1.2, 2.3, 2.3, 4.6, and 37.7 days, respectively, at $25^{\circ}C$. In this study, we could not determine the feeding potential of I. koebelei against the cucumber powdery mildew; therefore, and further studies are required to elucidate the potential of this species as a biological control agent, e.g., mass rearing, selection of low toxic chemical agents for Integrated Pest Management (IPM), and control techniques against powdery mildew in agro-ecosystems.

• Korean journal of applied entomology
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• v.46 no.3
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• pp.349-356
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• 2007

Three active components (Z8-12:Ac, E8-12:Ac, and Z8-12:OH) are known in sex pheromone of the oriental fruit moth, Grapholita molesta, and have been commercially available to apply for population monitoring and mating disruption. However, there have been variation among commercial products in pheromone composition and amount impregnated in each pheromone releaser. This study was performed to optimize factors influencing on pheromone monitoring of G. molesta by analyzing pheromone composition/amount, effective period of releaser, and trap type/placement in apple trees. High purity of Z8-12:Ac component was effective to attract males, in which 96% or more of cis acetate isomer component appeared to be optimal composition. Pheromone amounts ($0.01-1\;{\mu}g$) impregnated in each rubber dispenser did not give significant effect on monitoring during 90 days from June to August. "Delta" trap was much more efficient than "cone" trap to collect males. Trap installation was another factor, in which placing traps at canopy level was much efficient than at trunk or ground levels. Pheromone trap monitoring with these optimal factors indicated three to four adult peaks from June to September in addition to high overwintering population from April to May in pesticide-applied orchards in Andong, Korea.

• Korean journal of applied entomology
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• v.59 no.3
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• pp.257-264
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• 2020

The purpose of this study was to investigate the attraction distance range of pheromone traps used in the control of stink bugs, which are a problem in persimmon orchards, and the effects of sticky traps in increasing the efficiency of pheromone traps. Labeled individuals were released and then recaptured on pheromone and sticky traps. Riptortus clavatus was attracted to pheromone traps up to 60 m away. The capture rates of R. clavatus on sticky traps were 35%, 27%, 34%, 2.9%, and 0.6% after 0, 1, 2, 3, and 4 weeks To improve clarity, II have added this information from the details shown in the figures. Please check whether you agree.of exposure of the traps to the environment, respectively. Besides, when both pheromone and sticky traps were used at the same time following the release-recapture method, the capture rate of R. clavatus was 12 times higher than that by using pheromone traps only.

• Korean journal of applied entomology
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• v.5_6
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• pp.27-32
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• 1968

The larval instar of Scintillatrix djingischani OBENBERGER WES determined by measuring the head width of the larvae, some of which were bred in the room and the other collected in orchards during four years(1963-1966). Their growth ratio and variation were also studied. 1) The variation curve of the head width of the Iarvae distinctly appeared to be seven (7) curves, which seemed to have lived to be over seven(7) instars after six(6) times of molting. 2) In general, tile larvae live out to be 6-7 instar. Those pupated at 6th instar seem to over winter in tissue from November as matured. And those pupated in late Spring or early Summer after over wintering in canbium seem to be at 7th instar. 3) The standard deviation of the head width tends to grow larger except at 1st and 7th instar, while the coefficient of variation tends to decrease according as the number of instar increases. The growth ratio was found to decrease according as the number of instar increase except at 1 at and 2 nd instar. 4) To the growth of tee larval head width of this insect, Games and Campbell's formula was more applicable than Dyar's. 5) From the activties of larvae it is presumed that those bred in the year over winter in phelloderm or canbium at the 2 nd-3 rd instar, and the matured (2 year old) emerge the next year after over wintering in cambium or tissue at the 5th or 6th instar.

• Korean journal of applied entomology
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• v.13 no.4 s.21
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• pp.217-225
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• 1974

The damage by fruit-piercing moths in orchards, primarily on grapes cultivated on reclaimed hillsides in Koksung, Cholla Namdo, was surveyed during July to October, 1974. Moths collected at night, mostly with the aid of flash light, were then classified. Results are summairzed as follows; 1. In addition to the 14 species of fruit-piercing moths reported in Korea, 11 new species were collected lot the first time ia Korea. These include. Speiredonia retorta Clerck, Cocytodes coerulea Guenee, Metopta rectifasciata Menetries, Ophideres fullonica Linnaeus, Serrodes campana Guenee, Mythimna turca Linnaeus, Amphipyra livida Schiffermuller et Denis, Paralleia maturata Walker, Ophiusa tirhaca Cramer, Anomis mesogona Walker and Thyas dotata Fabricius. 2. The maximum emergence of moths in Koksung Orchard was from the 10th to the end of September. Only a few moths were observed befroe the begining of August or after October 10. 3. The number of moths flying to grape vines increased as the time advanced from sunset to midnight. Populations gradually decreased thereafter until 5:30 a. m., when only occasional moths were observed. 4. Average damage to grape fruits by these insects was virtually nil until August 10; with subsequent infestation rates of $1.0\%$ on August 15, $17.6\%$ on September 26, and $20.3%$ on October 4, respectively. 5. Fruits of less than 10 percent sugar content and higher than 6.2 acid value were free from damage by these moths, and those of higher sugar content and lower acid value to be more heavily attacked.