• International Journal of Industrial Entomology and Biomaterials
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• v.31 no.2
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• pp.35-39
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• 2015

The developmental responses of insects to temperature are important considerations in gaining a better understanding of their ecology and life histories. Temperature-dependent phenology models permit examination of the effects of temperature on the geographical distributions, population dynamics, and management of insects. Measurements of insect developmental and survival responses to temperature pose practical challenges that depend on the chosen modality, variability among individuals, and high mortality rates near the lower and upper threshold temperatures. Different temperature levels can significantly affect larval development of Eurema hecabe. The development of E. hecabe reared on leaves of Lespedeza cuneata was investigated at three temperature regimes (20, 25, and 30℃), a relative humidity of 60%, and a light:dark photoperiod of 14:10 h. The developmental time from larva to adult was 34.3, 20.6, and 17.9 d at temperatures of 20, 25, and 30℃, respectively. Pupal rate was 47.6%, 47.6%, and 61.9% at temperatures of 20, 25, and 30℃, respectively. The developmental threshold temperature estimated from larva to pupae was 8.1℃ with 381.7 degree-days. There is an increasing need for a standardized manual for rearing this butterfly species based on adequate knowledge of its ecology.

• The Korean Journal of Soil Zoology
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• v.5 no.2
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• pp.119-123
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• 2000

Effect of fluctuating temperatures on the development of the immature beet armyworm, Spodoptera exigua (H bner), was analyzed. At constant rearing temperature regimes, the estimated developmental threshold temperatures were varied among stages and instars, but had an average 13$^{\circ}C$ from egg hatch to adult emergence. Based on the 13$^{\circ}C$ threshold temperature, we set up three different rearing temperature regimes having the same day-degrees. Two fluctuating temperature regimes changed significantly the developmenta1 period expected by the constant rearing temperature regime. Under the same thermophase temperature (25$^{\circ}C$), the thermocycling regime with the higher cryophase temperature (10$^{\circ}C$) decelerated the developmental rate probably by lowering temperature limit thor development, but that with the lower cryophase temperature (5$^{\circ}C$) gave a negative developmental effect.

• Imaging Science in Dentistry
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• v.53 no.4
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• pp.303-312
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• 2023

Purpose: This study investigated the prevalence of developmental and acquired pathologic conditions associated with impacted third molars (3Ms) in a Southern Brazilian population and evaluated whether demographic and tooth characteristics were correlated with the presence of bone or tooth lesions. Materials and Methods: Panoramic radiographs were assessed for developmental (bone-related) or acquired (tooth-related) pathoses associated with impacted upper or lower 3Ms. Data on tooth positioning, tooth development, and patient demographics were collected. A trained, calibrated postgraduate student evaluated all images. Binary and multivariate logistic regression models were used to assess associations between outcomes and the demographic and radiographic variables. The threshold for statistical significance was set at 5% (P<0.05). Results: The sample comprised panoramic radiographs from 2054 patients, predominantly female (59.2%), with a mean age of 27.2±11.5 years. Overall, 4066 impacted 3Ms were evaluated, revealing 471 (11.6%) developmental and 710 (17.5%) acquired pathoses. Among the developmental pathoses, 460 (95.2%) were indicative of dentigerous cysts. Male sex, lower 3M location, vertical or distoangular positioning, and incomplete root formation were associated with an elevated likelihood of developmental pathology. Lower tooth position, complete root formation, and partial eruption were linked to an increased probability of an acquired pathology in the third or second molar. Conclusion: The prevalence of pathologic conditions associated with impacted 3Ms was low. Male sex, lower 3M placement, horizontal or distoangular positioning, and incomplete root formation were associated with developmental pathoses, while lower tooth position, complete root formation, and partial eruption were related to acquired pathoses.

• Korean journal of applied entomology
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• v.52 no.4
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• pp.387-394
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• 2013

The developmental times of mealworm beetle larvae, Tenebrio molitor were studied at six temperatures ranging from 15 to $30^{\circ}C$ with 60~70% RH, and a photoperiod of 14L:10D. Mortality of larval period was very low at 17 and $20^{\circ}C$ but did not die over $22^{\circ}C$. Developmental time of larva was decreased with increasing temperature. The total developmental time of T. molitor larvae was longest at $17^{\circ}C$ (244.3 days) and shortest at $30^{\circ}C$ (110.8 days). Egg and larvae were not developed at $15^{\circ}C$. The lower developmental threshold and effective accumulative temperatures for the total larval stages were $6.0^{\circ}C$ and 2564.1 degree-days, respectively. The relationship between developmental rate and temperature was fitted by a linear model and nonlinear model of Logan-6($r^2$=0.95). The distribution of completion of each development stage was well described by the 2-parameter Weibull function ($r^2$=0.8502~0.9390).

• Korean journal of applied entomology
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• v.52 no.1
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• pp.5-12
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• 2013

The Hawaiian beet webworm (Spoladea recurvalis) is one of the serious insect pests found on red beet (Beta vulgaris var. conditiva) in Korea. The study was conducted to investigate the development period of S. recurvalis at various constant temperatures, 15.0, 17.5, 20.0, 22.5, 25.0, 27.5, 30.0, 32.5 and $35.0^{\circ}C$, with $65{\pm}5%$ RH and a photoperiod of 16L:8D. The developmental period from egg to pre-adult was 51.0 days at $17.5^{\circ}C$ and 14.6 days at $35.0^{\circ}C$. The developmental period of S. recurvalis was decreased with increasing temperature. The relationship between the developmental rate and temperature was fitted well by linear regression analysis ($R^2{\geq}0.87$). The lower developmental threshold and effective accumulative temperature of the total immature stage were $10.4^{\circ}C$ and 384.7 degree days, respectively. The nonlinear relationship between the temperature and developmental rate was well described by the Lactin model. The relationship between the cumulative frequency and normalized distributions of the developmental period for each life stage were fitted to the Weibull function with $R^2=0.63{\sim}0.87$.

• Korean journal of applied entomology
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• v.43 no.2
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• pp.111-116
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• 2004

The development of Aphis gossypii was studied at various constant temperatures ranging from 15 to 35$^{\circ}C$, with 60-70％ RH, and photoperiod of 16：8 (L：D h). Mortality of A. gossypii was high in the early developmental stages, and at high temperatures. The total immature developmental period ranged from 4.6 to 11.5 days. The lower developmental threshold temperature and effective cumulated temperature for all immature stages were 5.0$^{\circ}C$ and 106.8 degree-day, respective. The nonlinear shape of temperature-dependent development was well described by the modified Sharpe and DeMichele model. The normalized cumulative frequency distributions of developmental period for each life stage were fitted to the three-parameter Weibull function.

• Korean journal of applied entomology
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• v.49 no.3
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• pp.199-204
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• 2010

The seasonal fluctuation of the large 28-spotted lady beetle, Henosepilachna vigintioctomaculata (Motschulsky), was observed in potato fields of Gangneung region, Gangwondo Province. The effects of their leaf consumption over a 24 hour period and developmental periods by different temperatures were investigated, and then the developmental threshold (DT) and effective cumulative temperature (ET) of each stage were calculated. Various developmental stages of H. vigintioctomaculata were captured in the fields from May to September, with three peaks in late May, late June, and late August. Leaf consumption by larval stages increased with the development of instar. The 4th instar larvae consumed potato leaves much more than other stages. Egg hatchability and emergence rate of H. vigintioctomaculata were lower at $10^{\circ}C$ and $30^{\circ}C$, but higher at around $20{\sim}23^{\circ}C$. The developmental periods of each stage became shorter as temperature increased; 90 days at $10^{\circ}C$, 40 days at $20^{\circ}C$ and 25 days at $25^{\circ}C$. Base on developmental velocity to temperature, calculated DT and ET were $7.3^{\circ}C$ and 83.

• 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.

• Korean journal of applied entomology
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• v.61 no.4
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• pp.563-575
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• 2022

Maruca vitrata is one of important pests in leguminous crops, especially red bean. We investigated the effects of temperature on development of each life stage, adult longevity and fecundity of M. vitrata for understanding the biological characteristics of the insect species at eight constant temperatures of 13, 16, 19, 22, 25, 28, 31, and 34℃. Eggs hatched successfully at all temperature subjected and larvae successfully developed to the adult stage from 16℃ to 31℃. The developmental period of egg decreased up to 31℃ and after then increased. The developmental period of larva and pupa, and adult longevity of M. vitrata decreased with increasing temperature. Lower and higher threshold temperature (TL and TH) were calculated by the Lobry-Rosso-Flandrois (LRF) and Sharpe-Schoolfield-Ikemoto (SSI) models. The lower developmental threshold (LDT) and thermal constant (K) from egg hatching to adult emergence of M. vitrata were estimated by linear regression as 12.8℃ and 280.8DD, respectively. TL and TH from egg hatching to adult emergence using SSI model were 14.2℃ and 31.9℃. Thermal windows, i.e., the range in temperature between the minimum and maximum rate of development, of M. vitrata was 17.7℃. In addition, we constructed the oviposition models of adult, using the investigated adult traits including survival, longevity, oviposition period and fecundity. Temperature-dependent development models and adult oviposition models will be helpful to understand the population dynamics of M vitrata and to establish the strategy of integrated pest management in legume crops.

• Korean Journal of Environmental Biology
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• v.27 no.3
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• pp.292-296
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• 2009

This study was conducted to estimate relationship between temperature and egg development of Nannophya pygmaea, an endangerd dragonfly species in Korea, using eight different temperature conditions (17, 20, 22, 25, 28, 30, 33, and $36^{\circ}C$). Eggs of N. pygmaea were collected from female adults inhabited a small wetland in Mungyeong-si, Gyeongsangbuk-do, Korea, in June 2007. As a result, hatching rates were 2.86, 17.09, 24.32, 39.67, 34.43, 40.57, 44.79, and 1.75% at 17, 20, 22, 25, 28, 30, 33, and $36^{\circ}C$, respectively. The nonlinear model of the temperature related to egg development was well fit to the modified Sharpe and DeMichele model. The derived lower developmental threshold temperature for egg hatching was $14.02^{\circ}C$(y=0.005988x-0.084, $r^2$=0.99), and the derived optimal development temperature was $30{\sim}35^{\circ}C$.