Temperatures experienced during larval development can exert profound effects on life-history traits expressed later during the adult stage in insects. In this study, we explored how larval rearing temperature (18, 23, and 28℃) would affect adult lifespan and reproductive performance in Drosophila melanogaster Meigen (Diptera: Drosophilidae). Larval developmental period was shortened with increasing rearing temperature. Larvae reared at colder temperatures reached the adult stage at a larger size than those reared at higher temperatures, thus conforming to the temperature-size rule. More importantly, we found strong evidence for significant effects of larval rearing temperature on both adult lifespan and early-life egg production rate. Lifespan increased progressively as the larval rearing temperature decreased from 28 to 18℃. In contrast, egg production rate was lower for flies raised at 18℃ compared to those at 23 and 28℃. These results highlight the importance of thermal environments experienced during the development in shaping life-history plasticity in insects.

Diet and temperature are the two most critical environmental factors affecting life-history traits in insects, but the combined effects of these factors have been rarely investigated. In this study, various life-history traits were recorded from adult and larval Drosophila melanogaster fed on one of eight synthetic diets differing in protein:carbohydrate ratio (P:C=1:16, 1:8, 1:4, 1:2, 1:1, 2:1, 4:1, or 8:1) under one of six ambient temperatures (13, 18, 23, 28, 31, or 33oC). The patterns of adult and larval life-history traits expressed across 48 diet-by-temperature combinations were visualized using thin-plate spline technique and the presence of any significant linear, quadratic, and correlational effects of diet and temperature on trait expressions was analyzed using a second-order polynomial multiple regression. Life-history traits exhibited qualitatively different responses to variations in both diet and temperature, with the maximal expression of each trait being achieved at a completely divergent region of the diet-temperature fitness landscape. In adult females, for example, lifespan was maximized at P:C 1:16 under 13oC, but fecundity was maximized at P:C 4:1 under 28oC. These results provide empirical support for the emerging notion that environmental factors, such as diet and temperature, can mediate life-history trade-offs in insects.

The nutritional quality of host plant is critically important for insect herbivores to maximize their fitness, but it is relatively unexplored whether the ingestion of a specific host plant will have the same effects on insects under different thermal conditions. We have used a multi-factorial experimental design to investigate how the nutritional quality of host plant and temperature interact to affect life-history traits in a generalist caterpillar Hyphantria cunea (Lepidoptera: Arctiidae) feeding on five different host plants. Caterpillars raised on Platanus occidentalis, Sophora japonica and Prunus x yedoensis exhibited substantially higher survival, faster growth and heavier mass at pupation than those on Cornus kousa and Betula platyphylla. Caterpillars developed more quickly and attained a smaller final body mass at higher temperatures, but the way that these traits responded to temperature differed by host plant. Caterpillars on P.occidentalis displayed a monotonic decrease in development time with increasing temperature, but the development time of those on P. x yedoensis declined with temperature in a biphasic manner. Furthermore, the rate at which pupal mass increased with decreasing temperature was much greater for caterpillars on P.occidentalis than those on P. x yedoensis.

A new collembolan species (Paranura rosea) which was native to Korea was selected for evaluating the effect of temperature on their biology. Development, and reproduction of P. rosea were investigated at 15, 20, 25 and 30℃ Hatchability of egg was not affected by experimental temperature, and the lower threshold temperature for development of P. rosea was estimated to be 7.53℃. The temperature reduced the juvenile and adult (maturity period). The intrinsic rate of natural increase and finite rate of increase per week at 20℃ which are maximum values showed significant difference with other experimental temperatures. Survival rate, cumulative reproduction and head capsule width was fitted by several models. Especially, the model which fitted for estimating head capsule width was used to determine their life stage. Estimated head capsule width of P. rosea at the initial oviposition varied with temperature from 0.36 ± 0.007 to 0.45 ± 0.007 with maximum at 20℃ and minimum at 30℃, and significant difference was observed at all the experimental temperature (P<0.05). However, estimated head capsule width at the last oviposition showed different statistically result at only 30℃. Molting frequency per week of one P. rosea was increased as the temperature increased. Based on this study, temperature greatly influenced on their life stage and reproduction. Therefore, relationship between temperature and P. rosea is very important for understanding their biology.

A phytoseiid mite, Neoseiulus californicus was newly found from Jeju citrus orchards in Korea and it is a polyphagous predator of mite and small insect pests as well as plant pollens. Recently in Korean apple orchards, Tetranychus urticae and Panonychus ulmi are imposing similar pest pressure. Even with ample information of this predator interacting with T. urticae, little is known on the interaction with P. ulmi. We investigated temperature effects on life history parameters of N. californicus when feeding on P. ulmi as prey in the laboratory condition to check the possibility to use this predatory mite in apple mite biological control. So, the development, survivorship and life-table parameters of the predator were studied by given mixed stages of P. ulmi as prey under the range of temperatures (15-34°C), RH 75±10%, and photoperiod 16L:8D to determine the effects of temperature. Temperature had a significant effect on mean development time from hatching to adult emergence and other life-history parameters. The results specified that the developmental time is decreased with increasing temperature between 15 and 30oC. Female development times were shorter at 25, 30 and 34°C (3.83±0.07, 3.37±0.24 and 3.53±0.11d, respectively) and were longest at 15°C (15.61±0.22d). Male developmental times were shorter than females ones at each temperature. The highest adult female life span (70.42±3.06d) and oviposition period (35.83±1.43d) observed at 15oC whereas the shortest at 34oC (13.06±1.03 and 7.3±0.94d, respectively). At 25oC, females laid maximum number of eggs (63.94±2) while minimum (16.59±0.98) was at 34oC. In sex ratio, utmost number of females (0.77±0.01) was counted at 25oC and lowest (0.67±0.01) at 34oC. Survivorship during immature development varied from 78.78 to 93.75% with the lowest value recorded at 20 and 34oC. From life table analysis, the shortest generation time (T=10.7d) resulted at 34oC. The highest net reproductive rate (R0=44.31; expected progeny per female) was found at 25oC. The intrinsic rate of natural increase (rm=0.29) and the finite rate of increase (λ=1.33) per day was estimated highest at 30oC. From this study, we found that N. californicus could successfully develop and oviposit vital eggs. Based on these results, we cautiously expect that N. californicus could be used as a biocontrol agent of spider mites in apple orchards when P. ulmi or T. urticae occurs singly or mutually.

현미(Sativa oryzae L., 품종 일품)에서의 화랑곡나방(Plodia interpunstella H)의 발육과 생명표와 통계량을 다섯상이한 온도 조건(17, 20, 25, 28, )에서 조사하였다. 온도에 대한 발육반응은 성 간에 차이가 없었다. 조사 온도범위에서 나방의 발육일수와 성충 수명은 온도가 높아짐에 따라 짧아져서 에서 각각 30.4일과 5.6일이었고 에서 각각 5.1일과 2.0일이었다. 우화율도 온도가 상승함에 따라 높아져서 에서 6.2%였고 에서 25.6%로 추정되었다. 그러나 부화율은 에서 5.3%로 정점에 도달한 후 다시 감소하여 를 경계로 이보다 높은 온도에서 부화가 저해되었다. 암컷 당 산란수는 17SIM 28의범위에서는 유의한 차이가 없었으나 에서는 유의하게 적어서 산란수와 부화율 간에 밀접한 관계가 있음을 암시하였다. 암컷을 산란은 온도가 높아짐에 따라 우화 2일후로 집중되었다. 순증가율은 에서 가장 높았고 와 의순으로 낮아졌으나 내적 자연증가율은에서 가장 높아 일당 0.065로 추정되었으며 이는 빠른, 높은 우화율, 산란의 우화초기집중에 의한 것으로 생각되었다.

본 연구에서는 저온환경에서 콘크리트 동해를 방지하기 위해 생석회의 화학반응을 활용한 발열시트 및 단열재를 사용하여 제작한 거푸집 특성을 실험을 통해 평가하였다. -10°C 정온조건에서 거푸집 실험 결과, 발열시트가 부착된 거푸집의 경우 발열시트 내부 생석회의 발 열로 인해 타설 초기에 일반거푸집에 비해 10°C이상 높은 온도이력을 보여주었고 단열재를 부착한 거푸집의 경우 콘크리트 수화열을 보존하 여 지속적으로 높은 온도를 유지하는 특징을 나타냈다. 아이소핑크와 발열시트를 부착한 거푸집과 진공단열재를 붙인 거푸집이 압축강도나 적산온도에서 가장 높은 값을 가졌다. 압축강도 측정시 진공단열재 및 아이소핑크와 발열시트를 부착한 거푸집이 재령 3일에서 약 5 MPa로 가 장 높게 측정되었다. 몽골 현지 외기온도에서도 실험을 하였는데 앞선 결과와 마찬가지로 발열시트, 단열재를 함께 붙인 거푸집이 48시간 동안 25°C 이상으로 가장 높은 온도이력를 나타내었다. 따라서 거푸집에 발열시트 및 단열재 부착을 함으로써 발열 및 단열효과로 인해 저온환경에 서 콘크리트 강도발현에 도움을 주는 것을 확인할 수 있었다.

This study is a basic studies for estimating the temperature history of the concrete after a fire. In this study measured the carbonation depth after fire resistance tests. As a result, according to the existing fire damage diagnostic methods, carbonation depth must be than 5cm. However, the actual measured carbonation depth was 1.5 ~ 3.3cm.

화재로 인한 건축물 구조부재의 파괴는 추가적인 경제적 손실과 인명피해를 가져오기 때문에 화재에 대한 구조부재의 안전성은 매우 중요하다. 화재에 노출된 철근콘크리트 구조부재의 경우, 부재의 열전도도에 따라 내부 온도가 상승하고 부재의 하중저항강도와 강성이 저하된다. 철근콘크리트 부재의 화재에 대한 구조성능 확보 여부는 일반적으로 표준화재실험을 통하여 입증한다. 콘크리트의 열전도도는 온도에 따라 변하기 때문에 20℃, 100℃, 200℃, 300℃, 400℃, 500℃, 600℃ 700℃, 800℃ 열적 정상상태의 콘크리트 블록을 이용하여 측정한다. 본 연구에서는 철근콘크리트 기둥의 화재에 대한 구조성능 확보 여부를 확인하기 위한 표준화재실험으로부터 얻어지는 열적 비정상상태의 일차원 온도분포 시간이력으로부터 콘크리트의 열전도도를 추출하는 방법을 제안하였다. 표준화재실험으로부터, 기둥의 표면에서 중심까지의 온도분포 시간이력을 얻었다. 콘크리트의 온도에 따른 열전도도 k(T)=α{(T/120)²-T/60+200}에 대하여 다양한 α값으로 온도분포 시간이력을 수치해석 하였고, 실험결과와 가장 오차가 작게 발생하는 α값을 결정하였다. 결정된 콘크리트의 온도에 따른 열전도도는 20℃, 100℃, 200℃, 300℃, 400℃, 500℃, 600℃ 700℃, 800℃ 열적 정상상태의 콘크리트 블록에서 측정된 콘크리트의 열전도도와 비교하였고, 제안된 수치해석에 의한 열전도도 산출방법이 유효함을 입증하였다.

To evaluaiton of heat history and spalling of concrete conlmn exposed to high temperature, □300×300×H450mm Specimen was used. fiber condition is Nylon 0.15vol.%, Polypropylene 0.1vol.% and steel fiber 0.3vol.%. The type of find aggregates are silica sand, wash sand and slag sand.