The present study was undertaken to ascertain the temperature development characteristics of Phthorimaea operculella (Lepidoptera: Gelechiidae) across its various developmental stages. To this end, the insect was subjected to six constant temperature conditions (13, 17, 25, 27, 32, 34±1°C), relative humidity (RH) levels of 65±5%, and photoperiods of 16 : 8 h light/dark. The developmental time of larvae was longest at 13°C, and as the temperature increased up to 35°C, the developmental time tended to become shorter. At the pupal stage, all individuals developing at 13°C perished and were excluded from the calculation of the development period for the development model. To ascertain the relationship between temperature and development, a regression model was employed for analysis. The lower threshold temperature of the total immature stage was determined to be 9.4°C, and the thermal constant was found to be 454.5DD. In the analysis of the temperature-development experiment, the Lactin 2 model exhibited an optimal fit (R 2=0.90-0.98) for the total immature stage of P. operculella.

Organoleptic parameters such as color, odor, and flavor influence consumer perception of drinking water quality. This study aims to evaluate the taste of the selected bottled and tap water samples using an electronic tongue (E-tongue) instead of a sensory test. Bottled and tap water's mineral components are related to the overall preference for water taste. Contrary to the sensory test, the potentiometric E-tongue method presented in this study distinguishes taste by measuring the mineral components in water, and the data obtained can be statistically analyzed. Eleven bottled water products from various brands and one tap water from I city in Korea were evaluated. The E-tongue data were statistically analyzed using multivariate statistical tools such as hierarchical clustering analysis (HCA), principal component analysis (PCA), and partial least squares discriminant analysis (PLS-DA). The results show that the E-tongue method can clearly distinguish taste discrimination in drinking water differing in water quality based on the ion-related water quality parameters. The water quality parameters that affect taste discrimination were found to be total dissolved solids (TDS), sodium (Na+), calcium (Ca2+), magnesium (Mg2+), sulfate (SO4 2-), chloride (Cl-), potassium (K+) and pH. The distance calculation of HCA was used to quantify the differences between 12 different types of drinking water. The proposed E-tongue method is a practical tool to quantitatively evaluate the differences between samples in water quality items related to the ionic components. It can be helpful in quality control of drinking water.

좁은가슴잎벌레는 십자화과작물을 가해하는 해충으로 알려져 있다. 본 연구는 온도가 좁은가슴잎벌레의 발육단계별 발육기간, 성충의 수 명과 산란특성에 미치는 영향을 파악하고자 성충 전 발육단계는 15, 20, 25, 27.5°C에서, 성충은 10, 15, 20, 25, 27.5°C 항온조건에서 조사하였 다. 알과 유충은 항온조건에서 다음 발육 단계로 성공적으로 발육하였다. 알, 유충, 번데기의 발육기간은 온도가 상승할수록 짧아지는 경향을 보 였다. 좁은가슴잎벌레의 발육영점온도, 유효적산온일도는 선형회귀분석을 통해 추정하였으며 알에서 성충출현까지 발육영점온도와 유효적산온 일도는 8.7°C와 344.73DD였다. 좁은가슴잎벌레 발육단계별 최저, 최고 온도의 한계는 Briere함수를 이용하여 추정하였으며 알에서 성충출현 까지 최저, 최고한계는 5.3°C와 40.4°C였다. 성충은 10°C와 27.5°C 범위에서 산란이 가능하였고 21.7°C에서 최대 약 627.5개의 알을 낳는 것 으로 추정되었다. 노화율, 나이별 생존율, 나이별 누적산란율, 온도의존 산란수와 관련된 성충모델들을 작성하였다. 본 연구에서 제시한 온도발육 모형과 성충산란모형은 좁은가슴잎벌레 개체군동태를 이해하는데 유용할 것이며 십자화과작물의 종합적 해충군관리체계를 마련하는데 기초자 료로 활용될것으로 기대된다.

대표적인 돌발 해충인 갈색날개매미충은 기주 범위가 넓고, 농경지만이 아니라 인근 야산, 산림 지역에도 분포하여 개체군 관리가 어려운 해충 중 하나이다. 따라서, 갈색날개매미충의 방제 효율을 증대시키기 위해서 농경지 작물 외에도 인근 산림에 분포하고 있는 목본식물에 대한 갈 색날개매미충 발육단계별 선호도 조사가 필요하다. 이에, 본 연구에서는 과수원 주변과 조경수, 산림의 주요 목본 식물들을 대상으로 갈색날개매 미충 발육단계별 선호도를 현장에서 조사하고, 선행 연구결과들과 비교하여 선호도가 높은 식물들을 선정하였다. 현장 조사와 선행 연구결과를 통하여 갈색날개매미충의 잠재적 목본 기주식물을 정리한 결과, 총 53과 120종이 확인되었고, 갈색날개매미충의 전 발육단계에 걸쳐 선호도가 높았던 기주는 산수유, 때죽나무에 불과하였으며, 발육단계별로 선호하는 목본 식물이 달라졌다. 발육단계에 따라서 선호 기주가 변동되는 이유 는 발육단계별로 선호하는 부위가 다르고, 생존에 필요한 물질에 따라서 기주가 선정되기 때문인 것으로 추정된다. 본 연구결과는 농경지 경제작 물뿐만 아니라, 농경지 주변 및 산림내 갈색날개매미충의 종합적인 방제 대책 수립에 도움이 될 것으로 예상한다.

The temperature-dependent development of Poinsettia thrips, Echinothrips americanus was studied at eight constant temperatures (15.0, 17.5, 20.0, 22.5, 25.0, 27.5, 30.0, and 32.5±1°C), 65±5% RH and photoperiod of 16L : 8D conditions. The developmental stages were divided into egg, 1st instar, 2nd instar, pre-pupa, pupa, and adult. The total developmental time in the immature stage was 40.4 days at 15.0°C and 11.6 days at 30.0°C, and it decreased with increasing temperature. The lowest temperature of the whole immature period was 10.7°C, and the cumulative temperature to complete the entire immature period was 217.4 degree days. The optimal development temperature (Topt) for the whole immature stage was estimated to be in the range of 30.51-31.21°C. Topt for each immature stage was 31.64-35.47°C at egg, 30.02-33.08°C at 1st instar, 29.16- 34.43°C at 2nd instar, 27.63-29.21°C at pre-pupa, and 29.81-30.12°C at pupa. In the analysis of the six non-linear models, Logan 6 model was the most appropriate as Zi (Weighting Factors) was 0.18.

The mass-rearing system for Neodryinus typhlocybae as a biological control agent of Metcalfa pruinosa was established. Depending on the density of host nymphs and plants, the average number of cocoons produced by the parasitoids was 5-8 and 70-150 cocoons per leaf and sapling of mulberry, respectively. There is a significant difference in cocoon length between females (6.10-6.46 mm) and males (4.20-4.62 mm). Sex determination of cocoons before emergence will be helpful for efficiently releasing this parasitoid in fields. The parasitic rate of N. typhlocybae at the semi-field condition was on average 13-17%. The release number of this parasitoid did not affect parasitism. Nevertheless, the population growth rate of M. pruinosa was reduced by increasing the release number of N. typhlocybae. The parasitoid offspring’s sex and bivoltine were influenced by the host age. On young host nymphs, the bivoltine portion of parasitoid increased. When parasitized on 4th or 5th nymphs, the offspring’s female ratio of N. typhlocybae increased. This result may be useful for potentially controlling mass rearing production of parasitoid.

The occurrence of Laodelphax striatellus (SBPH) in Korea ranged 0.3-19.3 individuals in 2021, and 0.3-23.3 individuals in 2022 during the investigation period. Nilaparvata lugens (BPH) was not observed in 2021, but N. lugens (BPH) showed the highest number(82.0 inds.) in late September of 2022. The occurrence of Sogatella furcifera (WBPH) was not severe during the study period. Compared to Korea’s situation, N. lugens (BPH) and S. furcifera (WBPH) in Asian regions showed high occurrence in Bangladesh and Sri Lanka. The results of the field survey could be confirmed with the occurrence pattern of about once or twice in their regions. Continuous monitoring is required for the best control of planthopper species in rice production regions of Asia. We anticipate that exchange of occurrence information and establishment of a control cooperation system will improve rice productivity in Asian regions by preventing outbreak of planthopper species and reducing damages caused by the species.