흑다리긴노린재 약충 및 성충에 의한 벼 이삭 피해를 다양한 조건에서 분석하였다. 흑다리긴노린재 약충 1마리를 1일간 접종하였을 경우 주당 평균 2.7개, 16마리를 16일간 접종하였을 때 주당 평균 132.3개의 반점미가 발생되었다. 접종밀도와 반점미 발생 입수와는 고도의 정의 상 관관계를 나타내었다(Y = 8.8446X, r2 = 0.9622). 출수기에 흑다리긴노린재 성충 1쌍을 접종한 경우 벼 수확 시 발생한 피해로 동할미율은 40.2%, 반점미율은 30.5%였으며, 16쌍을 처리한 경우 동할미율은 81.7%, 반점미율은 74.5% 발생되었다. 벼의 등숙 정도에 따른 피해 양상을 분석한 결과 출수 초기에 가해하였을 경우에는 벼의 등숙율을 감소시키는 경향을 보였으며, 중기 및 후기에 가해하였을 경우 동할미율과 반점미 율이 증가하는 경향을 나타내어 가해시기에 따라 벼 이삭 피해의 차이가 현저하였다.

벼에 반점미를 유발하는 흑다리긴노린재 [Paromius exiguus (Distant)]의 온도에 따른 산란 특성을 17.5~35°C 8개 항온조건 광주기 14L:10D에서 조사하고 산란모델 구축을 위한 단위 함수 개발 및 생명표 분석을 수행하였다. 성충 수명은 17.5°C에서 123.8일로 가장 길었고, 32.5°C에서 23.6일로 가장 짧았으며 온도가 올라감에 따라 수명도 짧아졌다. 암컷 한 마리당 총산란수는 30°C에서 585.2개로 가장 많았으며, 17.5°C에서 21.5개로 가장 적었다. 온도에 기반한 산란 모델 개발을 위해 성충노화율, 총산란수, 성충생존율 및 누적산란율 단위모델을 추정하였 다. 총 산란수(r2 = 0.83~0.85)를 제외한 3개의 단위모델 모두에서 높은 수준의 모델 적합성을 보였다(r2 = 0.92~0.98). 온도에 따른 흑다리긴노 린재 생명표 매개변수들을 추정하였다. 순증가율(R0)은 30°C에서 118.21로 가장 높았다. 평균 세대기간(T)은 32.5°C에서 32.99일로 가장 짧았 으며, 개체군 배수기간(Dt)은 30°C에서 5.69일로 가장 짧았다. 내적자연증가율(rm)과 기간증가율(λ)은 30°C에서 가장 커 각각 0.122, 1.129였다.

벼 반점미를 유발하는 흑다리긴노린재 [Paromius exiguus (Distant)] 성충의 산란 및 수명을 다양한 항온조건 (17.5, 20, 22.5, 25, 27.5, 30, 32.5, 37.5±1℃, RH = 20-30%, L:D = 14:10)에서 조사, 분석하고 산란 관련 모델들의 매개변수들을 추정하였다. 흑다리긴노린재 성충의 평균 수명은 17.5℃에서 82.0일로 가장 길었고, 온도가 올라감에 따라 짧아져 35℃에서는 평균 24.4일 생존하였다. 조사된 모든 온도 조건에서 산란 가능하였으며 평균 산란수는 25℃에서 455.1개로 가장 많았고 17.5℃에서 150.6개로 가장 적었다. 추정된 성충발육율 함수, 생존율 함수, 누적산란완료 함수는 비교적 높은 모형 적합성과 통계적 유의성을 보여주었다.

The developmental time of immature stages of Paromius exiguus (Distant) was studied at eight different constant temperatures (17.5, 20, 22.5, 25, 27.5, 30, 32.5 and 35°C) with a photoperiod of 14:10 (L:D) h on two host plants, Imperata cylinderica and Calamagrostis epigeios. On both host plants, the developmental time decreased with increasing temperatures. A significant difference in the developmental times was observed between two host plants for each nymphal stage and for the total nymphal stage as well. For completion of the total nymphal stage, the development time at 17.5 and 35°C were 69.6 and 16.6 days on I. cylinderica and 38.6 and 13.8 days on C. epigeios, respectively. The relationship between developmental rate and temperature was fitted to a linear regression model and the six nonlinear models (Lactin 1, Lactin 2, Briere 1, Briere 2, Logan 6 and Taylor). Except for the Taylor model, all of the five nonlinear models fitted the data for the total nymphal stage of the current study well, according to the high r2 value, on both host plants. The distribution of completion of each development stage was well described by the two-parameter Weibull function.

Paromius exiguus (Distant, 1883) is a serious insect pest in rice field adjacent to reclaimed land. They suck young ear of rice causing empty head of grain or pecky rice grain. During 2010 to 2012, we conducted to investigate the host-plant change of P. exiguus in Siwha reclaimed land, Hwaseong-si. In 2012, we also studied dispersal ability of P. exiguus from reclaimed land to adjacent rice fields. In early May, the adults aggregated on the grain parts of cogon grass (Imperata cylindrica) (Poales: Poaceae) after overwintering, and laid their eggs and nymphs developed into adults on the same host plants from middle May to late June. Second generation was observed at wood small-reed (Calamagrostis epigeios) (Poales: Poaceae) from late June to late July. At shooting stage of rice, adults moved to adjacent rice fields and third generation might be started. Although dispersal ability of adult of P. exiguus penetrated about 10 km into inland areas of Hwaseong-si, number of individuals of P. exiguus population was significantly declined with increasing distance from reclaimed land (Pearson’s correlation coefficient, r=-0.7357, p<0.0001). Unfortunately, further studies on population dynamics of P. exiguus in rice fields could not investigated, because pesticides were widely sprayed by aerial application in 14 August, 2012. Nevertheless, this results will be a useful information for management and control of P. exiguus in rice fields adjacent to reclaimed land.

The developmental time of immature stages of Paromius exiguus (Distant) was investigated at nine constant temperatures (15, 17.5, 20, 22.5, 25, 27.5, 30, 32.5, 35±1℃), 20-30% RH, and a photoperiod of 14:10h (L:D). Eggs did not develop at 15℃, and their developmental time decreased with increasing temperatures. Its developmental time was longest at 17.5℃ (28.2 days) and shortest at 35℃ (5.9 days). The first nymphs failed to reach the next nymphal stage at 17.5 and 35℃. Nymphal developmental time decreased with increasing temperatures between 20℃ and 32.5℃, and developmental rate was decreased at temperatures above 30℃ in all stages except for the fourth nymphal stage. The relationship between developmental rate and temperature fit a linear model and three nonlinear models (Briere 1, Lactin 2, and Logan 6). The lower threshold temperature of egg and total nymphal stage was 13.8℃ and 15.3℃, respectively. The thermal constant required to reach complete egg and the total nymphal stage was 109.9 and 312.5DD, respectively. The Logan-6 model was best fitted (r²=0.94-0.99), among three nonlinear models. The distribution of completion of each development stage was well described by the 3-parameter Weibull function (r²=0.91-0.99).

To find out the effect of global warming (long-term air temperature change) on insect population, we developed long-term monitoring program for Scotinophara lurida (Burmeister) and Paromius exiguus (Distant). The monitoring programs for these target insects are consisted of two main areas; Field monitoring and modelling of long-term population change. For the field monitoring, we conduct the survey of target insects on host plants, light trap monitoring, overwintering habitat sampling, and the monitoring of daily air temperature change. The field monitorings has been conducted for 10 and 4 years for S. lurida and P. exiguus, respectively. For the modelling of long-term population change, we have already developed basic phenology models for both insects. The developed phenology models are validated using yearly field sampling data and air temperature data. Environmental factors which could affect the populations of target insects are studied in laboratory to find out the magnitude of the effects. Based on the basic phenology models and parameters for newly found factors, long term population dynamics models for both insects will be developed.

Paromius exiguus (Distant) has caused serious damage by pecky grains around Gimpo paddy fields in 2001. We conducted field and laboratory studies to determine the seasonal occurrence and age distribution of P. exiguus on the three major host plants. The overwintering P. exiguus was found mainly on the basal part of gramineae weeds in various localities. After overwintering, in mid-May, the adults aggregated on the grain parts of Imperata cylindrica, laid their eggs and nymphs developed into adults on the same host plants. By the time, the Calamagrostis epigeios colony had newly occupied I. cylindrica areas, the nymphs and adults of first generation had already moved to the second host. The second generation of P. exiguus, after having completed its life cycle on C. epigeios, the newly emerged adults migrated to the rice plants and other gramineae weeds in early August. Afterwards, they complete its third generation cycle where they can move to the overwintering site again. P. exiguus has the five nymphal stages and each nymphal stage could be determined by head or prothoracic width. On the I. cylindrica and O. sativa hosts, the age distribution of P. exiguus showed a simple structure as each stage ratio increased stepwise with time. But in case of C. epigeios, as the newly emerged adults and immature nymphs continuously migrate after a month from the I. cylindrica, the age structure became remarkably complex. The peak nymphal density was observed when the ratio of third and forth instar was the highest in the population. The finding about the specific age structure on each generation of the insect would be very useful in control decision making on the major host plants. It is also important to consider the host"s specificity to pesticide sensitivity in relation to various nymphal stages.