Dysmicoccus brevipes (Cockerell), Dysmicoccus neobrevipes Beardsley and Pseudococcus longispinus (Targioni-Tozzetti) are widely-distributed pests that feeds on many economically important hosts, particularly tropical fruits and ornamentals. The potential distribution of these mealybug pests into South Korea remains a primary concern because of their high incidence in interceptions screened during inspection. Hence, these species prompted a modelling effort to assess their potential risk of introduction. Potential risk maps were developed for these pests with the CLIMEX model based on occurrence records under environmental data. The potential distribution of these pests in South Korea in the 2020s, 2050s and 2090s was projected based on the RCP 8.5 climate change scenario. Results show that D. brevipes, D. neobrevipes and P. longispinus have little potential for invasion in the exterior environment of South Korea due to high cold stress in the 2020s. However, for D. brevipes and P. longispinus, 3 and 86 locations in Jejudo, were predicted to be marginally suitable for this pest under future climate factors, respectively. In that respect, the results of these model predictions could be used to prepare a risk-based surveying program that improves the probability of detecting early D. brevipe, D. neobrevipes and P. longispinus populations.

미국선녀벌레는 2009년 발견이후 현재 131개 시군에 15,730ha가 발생되고 있다. 주로 단감 등 10여종 이상의 작물을 흡즙하여 피해를 준다. 2017년 이탈리아 파도바 대학에서 천적인 선녀벌레집게벌(Neodryinus typhlocybae)을 도입하여 국립농업과학원에서 생태특성 조사, 대량사육 기술개발 및 미국선녀벌레 발생 현장에 방사하고 있다. 선녀벌레집게벌은 미국선녀벌레 어린약충(1~3령)에 기생하면 암컷의 비율이 낮고 수컷은 2화 성 개체가 많아져 생산이 비효율적이다. 본 연구에서 어린약충에 기생할 때 보다 노숙약충에 기생할 경우 3배정 도 암컷생산의 비율이 높아졌고, 월동하고 있는 고치들을 5월 중순 무렵에 20℃의 서늘한 곳에 보관하면 우화시 기를 상온에 놓아둔 것에 비해 10일 이상 늦추는 결과를 얻었다.

During the larval development process of insects, juvenile hormone (JH) is essential for regulating various aspects of larval life, including growth, reproduction, and behavior, throughout their larval stage. The larval stage of Spodoptera frugiperda, when it consumes plant-derived metabolites, develops into pupae, but these pupae are unable to molt successfully. In this way, plant-derived metabolites contain or produce inhibitors of juvenile hormone, thereby disrupting the development of insect larvae and making them vulnerable to harm. Therefore, in this study, we established an in vitro screening system using yeast cells transformed with the Met-SRC juvenile hormone receptor of S. frugiperda. Through this system, we were able to identify juvenile hormone disruptors from plant-derived metabolites and confirm their developmental inhibitory effects on the larvae of S. frugiperda.

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 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.

기후변화로 인해 농경지의 병해충 발생 세대수가 증가하고 있으며, 노린재류 등을 포함한 일부 해충의 경우에는 발생량도 증가하는 경향을 보이고 있다. 볼록총채벌레, 붉은불개미 등 열대 및 아열대 지역 원산 외래해충의유입도 늘어나고 있는 실정이다. 따라서 우리는 이러한 외래종의 국내에서의 정확한 발생특성을 이해하고 이러한 해충의 발생지에서 기후노출지수(생육적온에 놓인 날의 횟수, 발생지역의 상대습도)와 해충의 고유생육 특성과 관련되는 민감도 지수(기주식물, 월동란밀도, 월동생존율 등) 그리고 돌발 해충의 발생시 방제할 수 있는 적응능력 등에 관한 자료를 취합하여 시군구별 이들 해충발생의 취약성(vulnerability)을 평가한다. 시군구별 이들 돌발해충의 발생 취약성 평가를 위한 실태조사(Surveillance)는 정점조사(Fixed plot survey)와 순회조사(Roving survey)를 실시하였고, 특정 지역에 특정 해충의 발생여부를 조사하는 일반실태조사(General surveillance)와 발생량 및 발생시기, 기주식물 등을 조사하는 특별실태조사(Specific survey)를 실시하였고 해충종별로 페로몬 트랩(pheromone trap), 황색끈끈이트랩(yellow stiky trap), 유아등 트랩(light trap) 등을 이용하여 발생여부 및 발생량을 조사하여 분석에 이용하였다.

농작물 해충 발생 실태조사란 조사지역에서 특정 해충의 발생시기, 발생량, 주요 기주직물의 종류 등에 관해 작물 생육기를 중심으로 주기적으로 조사하는 것을 말한다. 기후변화에 따라 새로이 발생하거나 피해도가 증가하는 병해충의 카테고리는 비래병해충, 돌발병해충, 남방계 병해충 등이 있다. 병해충 발생 ‘영향평가’라 함은 기후ꞏ기상 인자가 안정화된 현재의 농업생산시스템(적지, 생산성, 병해충, 생물다양 성 등)에 변화를 일으키는 영향값을 산출하는 것이다. 즉, 현재 상태를 기준으로 하여 기후변화에 따른 영향값 차이를 평가하는 것을 말한다. 병해충 발생 ‘취약성’ 이란 기후변동과 극한현상을 포함한 기후변화의 부정적 영향에 대해 특정 경작지나 그 경작지 내의 농작물이 민감하게 반응하거나 대처할 수 없는 정도를 말한다. 이번 연구는 영향평가 지표를 선정 및 이 기준으로 실시한 실태조사 결과를 가지고 특정 지역의 특정 해충에 대한 취약성 평가를 하는 방법에 관해 논한다.

The rice green caterpillar Naranga aenescens Moore (Lepidoptera: Noctuidae) is one of important destructive insect pests to Poaceae including rice and corn. We investigated the development periods of N. aenescens egg, larva, pupa and total immature at eight constant temperatures of 15.0, 17.5, 20.0, 22.5, 25.0, 27.5, 30.0, and 32.5°C, respectively. N. aenescens developed successfully from egg to the adult stage at all temperatures tested except 15.0°C. Developmental rate of N. aenescens increased as temperature increased from 15.0 to 30.0°C but declined at 32.5°C except pupa stage. The lower developmental threshold (LDT) and thermal constant (K) was estimated by linear regression. Higher temperature threshold (TH) and lower temperature threshold (TL) were calculated by two nonlinear functions. LDT and K from egg to adult emergence were 12.01°C and 330.84DD. The temperature range of N. aenescens from TL to TH using performance model (24.03) was wider than that from SSI model (19.77). Developmental completion of N. aenescens was described using a two-parameter Weibull distribution model. The adult emergence frequency of N. aenescens over full range of constant temperatures was simulated using developmental rate functions and Weibull function.

The small brown planthopper, Laodelphax striatellus, and the white backed planthopper, Sogatella furcifera, are important agricultural pests. L. striatellus could overwinter in Korean peninsula as nymph stage but S. furcifera could not. We investigated the survivorship and fecundity of two species for comparing population growth. The longevity and fecundity of two species were investigated at temperatures of 12.5, 15.0, 17.5, 20.0, 22.5, 25.0, 27.5, 30.0, 32.5, and 35.0℃. Adult longevity and fecundity of two species were significantly influenced by temperature. Longevities of L. striatellus were longer than those of S. furcifera at different temperatures. Specially, oviposition period of L. striatellus was twice as long as that of S. furcifera. Total fecundity per female of L. striatellus were also more than those of S. furcifera. The oviposition model of each species was consisted of three components - age specific survival rate, age specific oviposition rate and total fecundity per female. The relationship between adult developmental rate and temperatures was described by exponential function. The age specific survival rate and the age specific cumulative oviposition rate were explained by two parameter inversed-Weibull function and Weibull function. Temperature dependent fecundity was estimated using three parameter Gaussian function. Daily egg production of two species in relation to adult age and temperature was estimated.

Rice planthoppers (RPH) such as brown planthoppers (BPH), small brown planthoppers (SBPH), and white-backed planthoppers (WBPH) have been serious constraints to the rice production in Asian countries. It is important to manage their outbreak through the international cooperative network between concerned countries. RDA initiated a regional AFACI (Asian Food and Agriculture Cooperation Initiative) project for this purpose. And to facilitate information exchange of planthopper scouting data and technical knowledge between AFACI member countries, the internet-based AMIVS (www.amivs.org) Platform was being operated since 2011. In this system, scouting data includes daily light trap, aerial net data and weekly field collection data on BPH, WBPH, and SBPH and virus occurrence in scouting fields. Analysis results of the 2012 light trap and field collection data showed that each country or region has unique seasonal dynamics and dominance pattern of planthoppers according to the cropping pattern and environment. The high BPH density was mainly observed in Thailand and Vietnam. In other coutries, BPH density was rather low. Now, more and more scouting sites and data from member countries are entered in this system regularly, and we could expect that more substantial scouting information could be produced and shared in near future.

본 연구는 여름기간동안 대파에서 파좀나방 밀도에 따른 피해수준을 분석하고, 해충관리의 기초자료인 경제적피해수준을 제시하고자 수행되었다. 2009년부터 2010년까지 수원지역 대파 재배포장에서 성페로몬 트랩을 이용한 성충 발생 모니터링 결과, 3∼5월, 9월에 특히 많은 개체가 채집되었다. 파좀나방의 가해양상은 유충이 잎을 뚫고 들어가 내부에서 갉아먹으면 잎 표면이 초록빛을 잃고 하얗게 변하였고, 구멍이 생겨났다. 유충 1마리가 전체 유충기간동안 평균 1.6개 잎을 가해하였고, 11.9개의 구멍을 냈으며 피해면적은 1,321.6 mm2에 달했다. 망사케이지에 파좀나방 유충을 밀도수준별로 접종한 결과, 파좀나방 밀도수준에 따라 파의 평균 엽수의 감소와 피해엽률의 증가에 따라 총 수량 및 상품수량이 감소되었다. 피해해석 결과, 해충밀도와 피해엽률간에는 고도로 유의한 정(+)의 상관관계가 있는 회귀식을 구할 수 있었다. 이 식을 이용하여 대파의 상품화율 93%를 감안하여 설정한 피해한도인 피해엽률 7% 수준에서 파좀나방의 경제적 피해수준은 10주당 유충 1마리로 추정되었다.

경기지역에서 담배가루이의 발생 및 약제반응을 조사하였다. 담배가루이는 13개 시군에서 발생되었으며, 유전자(16S rRNA, MtCOI) 분석결과, 고양시 일부지역은 biotype B와 Q가 혼재되었으나, 그 밖의 지역에서 2005부터 국내 발생이 보고되었던 biotype Q로 나타났다. 채집곤충 및 기주식물의 total DNA에 대해 PCR을 통한 염기서열 분석과 southern hybridization 분석 결과 모든 지역에서 Tomato Yellow Leaf Curl Virus(TYLCV)는 검출되지 않았다. 5개 지역에서 채집한 6 개체군의 담배가루이를 실내사육하면서 유묘검정법으로 성충에 대한 살충제 감수성을 검정한 결과, 지역별로 다소 차이는 있었지만 네오니코티노이드계 약제의 경우 biotype B에게 높은 살충활성을 나타낸 반면 biotype Q에게는 상대적으로 낮은 살충활성을 나타내었다.

This study was conducted to investigate the insecticidal capacity of recombinant baculoviruses to Plutella xylostella and Spodoptera exigua larvae. For recombinant viruses, Bacillus thuringiensis cry1-5 crystal protein gene was introduced into the genome by fusion of polyhedrin-cry1-5 under the control of polyhedrin gene promoter. Recombinant AcPolh5-3006BiKTT and AcPolh5-3006 AvTox2 based on BiKTT and AvTox2, respectively, were constructed under the control of early promoter from Cotesia plutellae bracovirus. Mortality of S. exigua larvae was significantly higher when they fed on cabbage coated with ApEGFP (wild type) over 5.0×106 PIBs/ml. For AcPolh5-3006BiKTT and AcPolh5-3006AvTox2, mortality of P. xylostella and S. exigua larvae was significantly higher when they fed on cabbage coated with recombinant baculoviruses over 5.0×106 PIBs/ml and 1.0×104 PIBs/ml, respectively. The value of LD50 was lower in the treatments with AcPolh5-3006BiKTT (P. xylostella:1.2×106, S. exigua:1.3×104) or AcPolh5-3006AvTox2 (P. xylostella:2.3×106, S. exigua:1.4×104) than the treatments with ApEGFP (P. xylostella: not estimated, S. exigua:5.0×105). Survival time (ST50) of P. sylostella larvae was much shorter at AcPolh5-3006BiKTT (29.6h) than AcPolh5-3006AvTox2 (46.2h) while that of S. exigua larvae was much shorter at AcPolh5-3006AvTox2 (95.1h) than AcPolh5-3006BiKTT (101.9h) or ApEGFp (130.7h). The two recombinant baculoviruses were more effective in S. exigua larvae but slower speed of action.