• Animal Systematics, Evolution and Diversity
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• v.19 no.1
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• pp.139-147
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• 2003

Burckhardt (1987) combined Aphalaridae and Spondyliaspididae into the Psyllidae, as there were no character sets which had clearly defined these three families. During the analysis on the character evolution of the psyllids from the world including Australia, there were a few different results for the taxonomy of the Spondyliaspidinae. 52 species and 28 genera in the Australian native psyllids were dissected to examine the taxonomic position of the subfamily Spondyliaspidinae. All of the dissected psyllids in the subfamily Spondyliaspidinae had one follicle in the male testes, but the subfamilies of the Psyllidae except Spondyliaspidinae were having two or more follicles. By the characteristics with living on the Eucalyptus host plants recently evolved, having just one follicle which clearly defined it from other families and experienced an explosive specific diversification in the Gondwana region, it is reasonable to separate the subfamily Spondyliaspidinae from the family Psyllidae with two or more follicles.

• Animal Systematics, Evolution and Diversity
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• no.nspc2
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• pp.243-250
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• 1988

The wing morphometric characters of P.elaeagni complex feeding on the genus Elaeagnus plants was analysed by the multivariate methods using clustering of generalized distance and discriminant analysis. On the clustering of the species, the effect of sexual differences, seasonal variation and geographic population sensitively appeared . However, four species of this group was precicely divided by the discriminant analysis.

• Korean journal of applied entomology
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• v.39 no.2
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• pp.73-82
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• 2000

Two Psyllidae species of Cacopsylla pyricola (Foerster) and C. pyrisuga (Foerster)damaging pear trees have been reported in Korea. However, their ecological characteristics and damagepatterns have not been evaluated yet. To establish basic control measures of C. pyricola, field phenology,overwintering ecology, seasonal fluctuation and temperature-dependent development of C. pyricola wereexamined. C. pyricola overwintered under the bark scale of pear trees as winter form adults and theymoved to fruiting twigs from mid-February. Honeydew produced by C. pyricola nymphs and adults asthey feed caused serious black sooty mold on leaves and fruits. The seasonal occurrence of C. pyricolawas different every year. In 1993, characterized by cold temperature and heavy precipitation, C. pyricolapopulation was maintained highly during growing season. However, the population was decreased rapidlyfrom early July in 1994, year of hot and dry weather condition. In 1995, year of average temperature, thedensity of C. pyricola population was decreased during hot months of July and August, and rebuilt up inSeptember and October. The development periods of C. pyricola eggs were 13.33 days at 15"C, 9.32 daysat 20$^{\circ}$C, 7.82 days at 25"C, 6.60 days at 30$^{\circ}$C, and 7.75 days at 35$^{\circ}$C. The development periods ofnymphs were 33.75 days at 15OC, 23.77 days at 20$^{\circ}$C, 15.21 days at 25"C, and 17.40 days at 30$^{\circ}$C. Theirdevelopment periods and mortalities were increased in higher temperatures. The parameters of nonlineardevelopment model, Weibull and linear development models of Cacopsylla pyricola were estimated.models of Cacopsylla pyricola were estimated.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2002.11a
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• pp.61-61
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• 2002

• The Korean Journal of Zoology
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• v.35 no.1
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• pp.107-114
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• 1992

A new species, Psylla Koreana, arising on the Acer is described from Korea, and nineteen psyllid species from Mt. Sobaek are listed.

• Korean journal of applied entomology
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• v.35 no.3
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• pp.205-208
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• 1996

Psylla pyricola population from Suwon($37^{\circ}$16' N) begins to enter diapause by exposure to a photoperiod of 14hr light. Over 93% of adults were induced to enter diapause when exposed to 13hr loght period, and at 18 and $25^{\circ}C$, the critical photoperiod was not influenced. When the photoperiod was switched during the nymphal stage from 16L to 10L, no morph change was occurred in the 4th and 5th instars. Average number of eggs laid per female was 486.2 in winter form adult and 387.2 in summer form adults, and average oviposition periods were 34 and 24 days, respectively.

• Animal cells and systems
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• v.16 no.2
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• pp.145-153
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• 2012

The pear psylla, $Cacopsylla$ $pyricola$ (Hemiptera: Psyllidae), is a serious insect pest of commercial pear crops. The species, which resides on pear trees throughout its life cycle, is rapidly spreading in some regions of the world. The population genetic structure of the species collected from several pear orchards in Korea was studied to understand the nature of dispersal and field ecology of the species. The 658-bp region of mitochondrial COI gene and the 716-bp long complete internal transcribed spacer 2 (ITS2) of the nuclear ribosomal DNA were sequenced. Unlike other previously studied insect pests, the COI-based genetic diversity of the pear psylla was extremely low (maximum sequence divergence of 0.15%). This finding allowed us to conclude that the species may have been introduced in Korea relatively recently. ITS2 sequence-based analyses of phylogeny, population differentiation, gene flow, and hierarchical population structure all concordantly suggested that the pear psylla populations in Korea are neither genetically isolated nor hampered for gene flow. These genetic data are concordant with the dispersal of an overwintering winterform morph outside the non-pear habitat in the fall.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.4
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• pp.228-233
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• 2007

Pear psylla, Caccopsylla pyricola (Homoptera: Psyllidae), is a serious insect pest in pear orchards. C. pyricola overwinters as adults under rough bark scales of pear trees. When the weather warms up in the spring, the overwintered adults become active, climb up to the tree branches, and inhabit on fruit twigs to lay eggs. This study was conducted to develop a forecasting model for the onset of upward-movement of overwintered C. pyricola adults to control them by timely spraying of petroleum oil. The adult population densities were observed under rough barks (B) and on fruit twigs (T) of pear trees. Relative upward-movement rates (R) were calculated as T/(B+T). Low threshold temperatures for the activation of overwintered C. pyricola adults were selected arbitrarily from 5 to $9^{\circ}C$ at a $1^{\circ}C$ interval. Then, the days (D) when daily maximum air temperatures were above each low threshold temperature were counted from 1 February until to the dates with R $\geq$ 0.8. The same methods were applied for the prediction of the first observation of eggs. The variation of coefficients (CV) for the mean Des were lowest with the low threshold temperature of $6^{\circ}C$. At this selected threshold temperature, the upward movement of C. pyricola adults occurred with 12 D and they started laying eggs with 25 D. In the field validation, the model outputs with the $6^{\circ}C$ threshold temperature reasonably well explained the observed data in Suwon and Cheonan in 2002. Practical usages of the model were also discussed.

• The Korean Journal of Pesticide Science
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• v.17 no.1
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• pp.72-75
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• 2013

This study was performed to investigate the susceptibility and control efficacy of 27 registered insecticides against pear psylla, Cacopsylla pyricola in laboratory and field (Jincheon). Mortality of 3rd instar of C. pyricola was higher treated with pyrifluquinazon WG (97.7%), flonicamid WG (94.7%), abamectin EC (92.8%), and acetamiprid+buprofezin EC (86.8%) sprayed with field recommended concentration using a prayer in laboratory. These four insecticides also showed control effects of > 90% at 5 days after treatment in field.

• Korean Journal of Agricultural Science
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• v.43 no.2
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• pp.194-204
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• 2016

The pear psylla, Cacopsylla pyricola, is a very small sap-feeding insect of many commercial pear varieties that could be considered the most serious insect pest of pear. Detailed information on plant penetration activities of the pear psylla is essential to study its feeding behavior used to evaluate resistant traits to chemical control. The application of the electrical penetration graph technique (EPG) could provide a relevant insight into the nature of this resistance. EPG waveforms of C. pyricola were characterized on the basis of amplitude, frequency, voltage level, and electrical origin. Feeding behaviors of C. pyricola were recorded and analyzed by EPG analysis. During EPG monitoring, waveform PA occurred at the start of stylet penetration of pear leaf epidermal cell. Waveform PB followed, in which stylet secreted saliva was observed. Waveforms PC1 and PC2 involved penetrating and sucking behaviors in parenchyma cells and vascular parenchyma, respectively. In addition, waveform PC1 represented salivation into bundle sheath cells and ingestion from parenchyma. Otherwise, behaviors of salivation into phloem and ingestion from phloem produced waveforms PE1 and PE2, respectively. On the other hand, ingestion from xylem tissues showed waveform PG. Among the feeding patterns of C. pyricola described above, phloem feeding patterns occurred most frequently, followed by xylem feeding and parenchyma penetration patterns in descending order.