• Korean journal of applied entomology
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• v.54 no.3
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• pp.179-189
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• 2015

In 2014, surveys were conducted in Korea to study the geographical distribution, host plants, and potential habitats of Pochazia shantungensis. The occurrence of P. shantungensis was confirmed in 43 cities and counties nationwide, and identified for the first time in Gyeongsangbuk-do. P. shantungensis has a wide range of diverse host plants comprising 113 species in 53 families, including crops, fruits, and forest trees. Since the hemipteran was first reported in Korea, 138 species from 62 families have been identified as P. shantungensis host plants. This insect feeds on the following major host plants: Malus pumila, Aralia elata, Styrax japonicus, Salix gracilistyla, Broussonetia kazinoki, Albizia julibrissin, Ailanthus altissima, Castanea crenata, Robinia pseudoacacia, and Cornus officinalis. Potential habitat was analyzed in the present study using the Maxent model with 12 variables (8 climate, 1 land cover, 1 forest type, 1 ecological zoning, and 1 distance). The model ROC AUC was 0.884, indicating a high accuracy. In the present study, precipitation of warmest quater, mean temperature of warmest quarter, forest type, and land cover were the most significant factors affecting P. shantungensis distribution, and habitat.

• Korean journal of applied entomology
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• v.55 no.3
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• pp.223-233
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• 2016

In order to identify a new control measure for a sporadic insect pest, Pochazia shantungensis, 23 types of essential oils were screened for their repellent effects, with an olfactory test using a Y-tube olfactometer. Results indicated that 21 essential oils, except lemongrass oil and peppermint oil, did not show repellent activity against P. shantungensis. The repellent effect of peppermint oil was over 80%. When 0.1, 0.5, and $1{\mu}l$ of peppermint oil were used, the rate of repelling of P. shantungensis gradually increased, and was as high as 76.5% when $10{\mu}l$ was used. The main components of peppermint oil were 1,8-cineole, iso-menthyl acetate, menthone, and menthol, at 4.7, 8.0, 23.8 and 53.7%, respectively. When the three main components were mixed using a Y-tube olfactometer, a strong repellent effect (76.2%) was observed when $5{\mu}l$ was used. Peppermint oil showed a repellent and ovipositional repellent effect against P. shantungensis in the field. However, this activity persists only for a short period, and high concentrations can lead to phytotoxicity. Therefore, it is necessary to develop ideal formulations.

• Korean journal of applied entomology
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• v.60 no.1
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• pp.99-103
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• 2021

This study was conducted to investigate the hatching rate of Pochazia shantungensis according to the treatment method of machine oil and the effect on apple quality by spawning. In the effect of machine oil treatment, when 20 times of the machine oil was spread by brush, the average hatching rate was 0.57%, and the sprayed branches showed an average hatching rate of 1%. When the machine oil agent was applied 50 times, the hatching rate was about 35% to spread by brush, whereas the spray treatment showed about 77%, so there were no difference from the non-treatment considering the deviation. There was no statistically significant difference in the quality of fruit even when apple fruits were fruited in the following year in the results of spawning and non-spawning of P. shantungensis in Hongro and Fuji varieties. In addition, there was no statistical significance in the difference between branch breakage and growth caused by spawning of P. shantungensis.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.453-457
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• 2016

This study investigates the hatching periods and hatchability of the eggs of Pochazia shantungensis at different collection times from 2011 to 2014, and the effect of temperature on the growth of P. shantungensis nymphs in an area of its outbreak. The hatchability of P. shantungensis eggs varies with their collection time; their hatchability in late November was higher than that in March of the next year, but no difference was observed in their hatching periods. The hatching periods of the eggs were 51.2, 31.3, 24.8, 19.4, 17.1, and 19.4 days at 15, 18, 21, 24, 27, and $30^{\circ}C$, respectively. The hatchability was above 70% at temperatures ranging from 18 to $27^{\circ}C$. The hatching time of the overwintered eggs in the Gurye region in Korea was reduced by 9 days from 2011 to 2014. The hatching rate was relatively higher when the average temperature in the winter season was relatively warmer. The dvelopmental periods of the first to fifth nymphs were 82.8, 58.0, 45.8, and 39.6 days at 18, 21, 24, and $27^{\circ}C$, respectively, at the relative humidity of 40~70%, and a photoperiod off 14 h light:10 h dark. The higher the temperature, the shorter the developmental period. At $30^{\circ}C$, all life stages after the fourth nymph died. Thus, the optimum growth temperature was estimated to be $27^{\circ}C$. For all life stages from the egg to the fourth nymph, the relationship between the temperature and developmental rate was expressed by the linear equation Y = 0.0015 X - 0.014. The lower developmental threshold was $9.3^{\circ}C$ and the effective cumulative temperature was 693.3 degree-days. The lower developmental threshold of approximately $3.8^{\circ}C$ was the lowest at the fourth nymph stage.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.2
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• pp.129-138
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• 2021

Living modified organisms (LMOs) are managed by seven government agencies according to their use in South Korea. The Ministry of Environment is responsible for LMOs used for environmental remediation. This study aimed to develop guidelines for assessing potential risks posed by transgenic plants used for remediation to insect ecosystems by investigating arthropod communities in sunflower fields. A total of 2,350 insects and spiders belonging to 134 species of 10 orders and 71 families were collected from sunflower fields over four growth stages ranging from anthesis to seed maturity. At the R3 phase of flower-bud formation, Chironomidae sp. of a decomposer insect guild presented the highest density, while Apis mellifera of a pollinator guild was the most abundant in the R5.8 phase of flowering. During the R7 seed-filling phase and the R9 phase of seed maturity, herbivorous Pochazia shantungensis predominated. During the R9 phase, richness and diversity indices of arthropod communities were distinctly lower whereas their dominance indices were significantly higher than those at other phases. In addition, the composition of arthropod communities was strongly correlated not only with the sampling date, but also with the sampling method depending on the growth stage of sunflowers. Our results suggest that appropriate sampling timing and methods should be considered in advance and that long-term field trials that cover a variety of environmental conditions should be carried out to evaluate potential risks to insect ecosystems.

• Korean journal of applied entomology
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• v.56 no.2
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• pp.121-133
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• 2017

This study was conducted to investigate the community structure of arthropods, including various insect pests and their natural enemies, in walnut orchards. Furthermore, we tried to compare the species richness and community structure of arthropods by three different sampling methods, including beating, funnel trap, and pitfall trap. Arthropods were surveyed in three walnut orchards located at Gimcheon, Buyeo, and Hwaseong in South Korea from May to September, 2016. A total of 408 arthropod species were identified from 4,372 individuals, and 63 species were collected in all study sites. The species richness was the highest in funnel trap, while the abundance was the highest in pitfall trap. The species composition of the insects collected by the beating method was more similar to that of the funnel trap than the pitfall trap. Although the distributions of the economically important pests were different according to the study sites, six species, including Dichocrocis punctiferalis, Pseudaulacaspis pentagona, Gastrolina depressa, Lycorma delicatula, Metcalfa pruinosa, and Pochazia shantungensis, are the potentially important pests in walnut orchards. We also found a variety of predators and parasitoids, which will be important for walnut pest management.