• Korean journal of applied entomology
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• v.56 no.4
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• pp.387-394
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• 2017

Temperature-dependent oviposition model and life table parameters of Paromius exiguus (Distant), the causal agent of 'pecky' rice grain were examined at eight constant temperatures (17.5, 20, 22.5, 25, 27.5, 30, 32.5, and $35{\pm}^{\circ}C$) and a photoperiod of 14:10 (L:D) h. Unit functions of the oviposition model were developed and life table parameters were estimated. The longevity of P. exiguus adults decreased with increasing temperature (123.8 days at $17.5^{\circ}C$ and 23.6 days at $32.5^{\circ}C$). Total fecundity was highest at $30^{\circ}C$ (585.2 eggs/female) and lowest at $17.5^{\circ}C$ (21.5 eggs/female). In order to develop a temperature-dependent oviposition model, adult aging-rate, temperature-dependent fecundity, age-specific survival rate, and age-specific cumulative oviposition rate equations were estimated. All unit equations ($r^2=0.92{\sim}0.98$) except for the temperature-dependent fecundity equation ($r^2=0.83{\sim}0.85$), described oviposition characteristics of P. exiguus adequately. Life table parameters of P. exiguus were estimated at various constant temperatures. Net reproduction rate ($R_0$) was highest at $30^{\circ}C$ (118.21). Mean generation time (T) was shortest at $32.5^{\circ}C$ (32.99 days) and doubling time (Dt) was shortest at $30^{\circ}C$ (5.69 days). The highest values of intrinsic rate of increase ($r_m$) and finite rate of increase (${\lambda}$) were 0.122 and 1.129 at $30^{\circ}C$, respectively.

• Korean journal of applied entomology
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• v.44 no.3 s.140
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• pp.231-235
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• 2005

This study was conducted to obtain the optimal spray time for Pseudaulacaspis prunicota (Maskell) (Homoptera: Diaspididae) in early seaon in Jeju. Oviposition time of overwintered females and activity of hatched nymphs of P. prunicola were monitored, and the phenology data were compared with the outputs estimated by a degree-days model of P. pentagona (Targioni-Tozzetti)). Overwintered females of P. prunicola began to lay eggs from mid to late April, and the eggs started to hatch from early May followed by the active migration of the hatched nymphs during mid May. The phenological events of P. prunicola in early season were likely comparable with those of P. pentagona reported in southern Korea and in central Japan. A degree-day model, which predicts the proportion of >50% hatched egg batches of P. pentagona (y=1[exp(-(-a+bx))]; y, proportion; x, degree-days based on $10.5^{\circ}C$ from 1 January; a=-18.80 and b=0.073), accurately described the migration time of P. prunicola hatched nymphs. Thus, it is considered that the degree-day model can be used for predicting the optimal spray time for P. prunicola in early season.

• Korean journal of applied entomology
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• v.60 no.4
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• pp.449-462
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• 2021

We analyzed the effects of temperature on the survival, development, and reproduction of the non-diapause Asian corn borer, Ostrinia furnacalis (Lepidoptera: Crambidae). A 16:8 h light:dark photoperiod was supplied to the non-diapause stages of O. furnacalis. The insects were raised on an artificial diet at seven constant temperatures between 15 and 35℃ for immature stages, and eight temperatures between 13 and 33℃ for the adult stage. The survival rate of eggs exceeded 70% at all temperatures, whereas survival of larvae was as low as 7.4% at 15℃. The developmental periods of the immature stages decreased with increasing temperature, but the larval period did not decrease further at 35℃. The pupal weight increased with increasing temperature, but the female weight decreased at 35℃. Variations with different last larval instars within the colonies at different temperatures were observed. Adults produced offspring at all tested temperatures. Adult longevity and the pre-oviposition and oviposition periods decreased with increasing temperature, but the pre-oviposition period increased at 33℃. Total fecundity exceeded 400 viable eggs at 22℃ and 31℃. The mean daily fecundity during the oviposition period and the mean daily fecundity on the day of oviposition increased with increasing temperature, but decreased at 33℃. Daily fecundity sharply increased at earlier adult ages and slowly decreased thereafter. The simulated oviposition frequency was greatest at 22℃. The lower developmental threshold temperatures were estimated to be the lowest at 9.7℃ for the first instar larva and the highest at 14.7℃ for the 5th to last instar larval stage, using a linear model.

• 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 applied entomology
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• v.38 no.1
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• pp.29-33
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• 1999

Orius strgicollis Poppius is an endemic natural enemy of thrips recently found. To estimatethe optimum temperature for rearing in laboratory, development and oviposition of 0. strigicollis wasstudied at 15, 20, 25 and 30$^{\circ}$C with a 16L : 8D photoperiod and 60-80% RH. Cotton aphid, Aphisgossipyii, was supplied as prey. Total number of eggs laid per female ranged from 39.1 to 68.5 with thehighest at 25$^{\circ}$C. Adult longevity decreased as temperature increased, and the reverse was true for eggsurvivorship. Survivorship of larvae was 26.7,43.3, 76.7 and 46.7% at 15, 20, 25 and 30$^{\circ}$C, respectively.Duration of eggs and larvae at tested temperatures ranged from 3.4 days to 18.9 days and from 9.4 days to45.6 days, respectively. A linear regression model could describe development of the predator as afunction of temperature (R2=0.949-0.997). The lower developmental threshold temperatures for egg,larvae, and total immature stage were estimated to be 12.4, 11.4, and 11.6"C, respectively.6"C, respectively.vely.

• Applied Microscopy
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• v.28 no.1
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• pp.91-105
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• 1998

The present study is undertaken to investigate the hypertrophical changes of the corpus allatum (corpora allata, CA) after the ovariectomy in Blattella germanica. In particular, the ultrastructural aspects of the normal and ovariectomized conditions, and induced factors of the hypertrophic phenomenon are focused. Ultrastructure of the CA from an immediately emergent adult is similar to that of the last larval stage that has stopped secreting juvenile hormone. The CA is composed of undifferentiated cells, exhibiting an electron-lucent matrix, a few mitochondria and less smooth endoplasmic reticulum. The karyoplasm occupy most of the cytoplasm. Electron-dense materials are filled with the intercellular spaces and gap junctions are also found. Almost no ultrastructural changes have been noticed during seven days until the oviposition. However, considerable changes in structure have been detected soon after the oviposition. Mitochondria are increased dramatically in number and cristae, and changed to the filamentous form with a high electron density. In addition, Golgi complexes, microtubules, and polysomes are also increased. After an oviposition, the total volume of the CA are decreased again. The volume of the CA are increased continuously, hypertrophy, after the ovariectomy. Morphological aspects of the CA in an early stage after the removal are similar to the structure of the secondary egg maturation. Large and electron dense globules are observed in the ovariectomized CA cytoplasms and they are present in those cells for a long period of time. Yet such a hypertrophical phenomenon occur only in the specific cells. The hypertrophy are caused by hollowing the part of the CA cells and later filling such site with polysomes. In 42 days after the ovariectomy, the nuclear membranes disappear in the CA cells, thus, exhibiting the prokaryotic-like features. Some results of the current study will contribute to the establishment of the model that explain unusual changes accompanied by certain treatment in insects and/or further in animals.

• Korean journal of applied entomology
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• v.61 no.3
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• pp.435-447
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• 2022

The soybean podborer, Matsumuraeses falcana (Lepidoptera: Tortricidae), is one of important pests in soybean crop. In the purpose of forecasting population dynamics of M. falcana, we investigated the effects of temperature on development of each life stage, adult longevity and fecundity of Matsumuraeses falcana at seven constant temperatures of 10, 13, 19, 22, 25, 28, and 31℃. Eggs hatched successfully at all temperature subjected. M. falcana developed from egg hatching to adult emergence at the tested temperatures except 10, 13, and 31℃. The developmental period of each life stage and adult longevity of M. falcana decreased as temperature increased. The lower developmental threshold (LDT) and thermal constant (K) from egg hatching to adult emergence of M. falcana were estimated by linear regression as 10.2℃ and 492.04DD, respectively. Lower and higher threshold temperature (TL and TH) were calculated by the Lobry-Rosso-Flandrois (LRF) and Sharpe-Schoolfield-Ikemoto (SSI) models. TL and TH from egg hatching to adult emergence using SSI model were 16.7℃ and 29.1℃. Thermal windows, i.e., the range in temperature between the minimum and maximum rate of development, of M. falcana was 12.4℃. We constructed the adult oviposition model of M. falcana using adult survivorship and fecundity. Temperature-dependent immature development and adult oviposition models will help constructing the population model of M. falcana and developing the strategies of integrated pest management in soybean fields.

• Korean journal of applied entomology
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• v.55 no.2
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• pp.119-128
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• 2016

This study was conducted to develop temperature-driven models for a population model of turnip aphid, Lipaphis erysimi: nymphal development rate models and apterious adult's oviposition (larviparous) model. Nymphal development and the longevity and fecundity of adults were examined on cabbage at six constant temperatures (10, 15, 20, 25, 30, $35{\pm}1^{\circ}C$, 16L:8D). L. erysimi nymphs did not survive at $10^{\circ}C$. Development time of nymphs increased with increasing temperature up to $30^{\circ}C$ and thereafter slightly decreased, ranging from 18.5 d at $15^{\circ}C$ to 5.9 d at $30^{\circ}C$. The lower threshold temperature and thermal constant were estimated as $7.9^{\circ}C$ and 126.3 degree days, respectively. The nonlinear model of Lactin 2 fitted well for the relationship between the development rate and temperature of small (1+2 instar), large (3+4 instar) and total nymph (all instars). The Weibull function provided a good fit for the distribution of development times of each stage. Temperature affected the longevity and fecundity of L. erysimi. Adult longevity decreased as the temperature increased and ranged from 24.4 d at $20^{\circ}C$ to 16.4 d at $30.0^{\circ}C$ with abnormal longevity 18.2 d at $15^{\circ}C$, which was used to estimate adult aging rate model for the calculation of adult physiological age. L. erysimi showed a maximum fecundity of 91.6 eggs per female at $20^{\circ}C$. In this study, we provided three temperature-dependent components for an oviposition model of L. erysimi: total fecundity, age-specific cumulative oviposition rate, and age-specific survival rate.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.4
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• pp.158-166
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• 2008

The pumpkin fruit fly, Bactrocera depressa (Tephritidae: Diptera), is one of the most important pests in Cucurbitaceae plants. This study was conducted to investigate the basic ecology of B. depressa, and to develop a forecasting model for predicting the time of adult emergence in early season. In green pumpkin producing farms, the oviposition punctures caused by the oviposition of B. depressa occurred first between mid- and late July, peaked in late August, and then decreased in mid-September followed by disappearance of the symptoms in late September, during which oviposition activity of B. depressa is considered active. In full-ripened pumpkin producing farms, damaged fruits abruptly increased from early Auguest, because the decay of pumpkins caused by larval development began from that time. B. depressa produced a mean oviposition puncture of 2.2 per fruit and total 28.8-29.8 eggs per fruit. Adult emergence from overwintering pupae, which was monitored using a ground emergence trap, was first observed between mid- and late May, and peaked during late May to early June. The development times from overwintering pupae to adult emergence decreased with increasing temperature: 59.0 days at $15^{\circ}C$, 39.3 days at $20^{\circ}C$, 25.8 days at$25^{\circ}C$ and 21.4 days at $30^{\circ}C$. The pupae did not develop to adult at $35^{\circ}C$. The lower developmental threshold temperature was calculated as $6.8^{\circ}C$ by linear regression. The thermal constant was 482.3 degree-days. The non-linear model of Gaussian equation well explained the relationship between the development rate and temperature. The Weibull function provided a good fit for the distribution of development times of overwintering pupae. The predicted date of 50% adult emergence by a degree-day model showed one day deviation from the observed actual date. Also, the output estimated by rate summation model, which was consisted of the developmental model and the Weibull function, well pursued the actual pattern of cumulative frequency curve of B. depressa adult emergence. Consequently, it is expected that the present results could be used to establish the management strategy of B. depressa.

• Korean journal of applied entomology
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• v.61 no.3
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• pp.461-473
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• 2022

Matsumuraeses phaseoli is one of important pests in soybean crops, especially adzuki beans. We investigated the effects of temperature on development of each life stage, adult longevity and fecundity of M. phaseoli for understanding the biological characteristics of M. phaseoli at ten constant temperatures of 7, 10, 13, 16, 19, 22, 25, 28, 31, and 34℃. Eggs hatched successfully at all temperature subjected except 7℃ and 34℃. The developmental period of each life stage and adult longevity of M. phaseoli decreased as temperature increased. 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. phaseoli were estimated by linear regression as 9.04℃ and 422.97DD, respectively. TL and TH from egg hatching to adult emergence using SSI model were 20.0℃ and 32.3℃. Thermal windows, i.e., the range in temperature between the minimum and maximum rate of development, of M. phaseoli was 12.3℃. We constructed the adult oviposition model of M. phaseoli using adult survivorship and fecundity. Temperature-dependent development models and adult oviposition models will be helpful to understand the population dynamics of M. falcana and to establish the strategy of integrated pest management in soybean fields.