Rice serves as the staple food for many Asian countries. However, it faces a significant threat from various Hemiptera species, including Nilaparvata lugens, Sogatella furcifera, Laodelphax striatellus, and Nephotettix cincticeps, which can cause devastating diseases. These species are economically significant pests of rice. Traditional morphology-based methods have proven inefficient in accurately distinguishing these pests at the species level. In this study, we present a successful approach for designing species-specific primers and their application in both general and multiplex PCR as well as loop-mediated isothermal amplification (LAMP) assays, widely adopted molecular tools for species identification. Each primer set incorporates a species-specific sequence of at least 2 base pairs in both the forward and reverse primers. These primers have demonstrated exceptional diagnostic accuracy in conventional and multiplex PCR. Additionally, our study showcases the high sensitivity of LAMP, successfully achieving positive amplification with genomic DNA quantities ranging from 100pg to 10pg. In summary, these techniques provide an efficient means of diagnosing planthoppers in a large number of field-collected or individual samples.

벼는 동남아에서 매우 중요한 작물이며 작물 재배면적의 대부분을 차지하고 있다. 벼 생산량 증대를 위해 주요 문제 해충인 멸구류를 방제하는 것이 중요하다. 방제 방법으로는 농약을 이용한 방제가 주를 이루고 있는데, 규정상 농약은 공인 된 등록약제를 사용하도록 되어 있다. 그러나 동남아 주요 벼 재배국가의 방제 농약의 정보는 국내에 알려져 있지 않기 때문에 멸구류 방제용 등록 약제를 소개한다. 1. 등록 약제는 국가별로 소폭 차이는 있으나 그 계통이 네오니코티노이드계가 가장 많은 비중을 차지한다는 점에서 공통점을 보였다. 이러한 특성 때문에 동일 약제의 연용으로 인한 저항성 발현 문제가 잠재되어 있다고 판단된다. 2. 이는 동남아만의 문제가 아니라 장기적으로는 기류를 타고 멸구류가 비래해오는 우리나라에도 영향을 줄 수 있다는 것을 시사하고 있다. 3. 따라서 향후 동남아 국가간 공동방제 등 상호협조가 필요하며, 농촌진흥청에서 추진하고자 하는 AFACI 사업을 통해 국가별 약제저항성 검정 및 방제 표준화기술 확립 등과 같은 지원에 협력을 해주어야 할 것으로 판단된다.

A ricanid planthopper, sometimes so called Ricania shantungensis, has been regarded as a serious invasive pest in Korean peninsula. It belongs to family Ricaniidae comprised of 40 genus and more than 400 species worldwide, and only 6 species recognized in Korea. The invasive planthopper has a wide host range including economic agricultural crops such as apple, peach and pear. In the meantime to investigate natural enemies for biological control, we have found an egg parasitoid. In this study, we report a new species of genus Phanuromyia, an egg parasitoid of the ricanid planthopper. Morphological characteristics of male and female are described in detail with high resolution images.

멸구과(Delphacidae) 8종의 internal transcribed spacer 2 (ITS2) DNA 염기서열로 종간 차이 추정값을 비교하고 분자계통수를 추론하였다. ITS2 DNA 염기서열 길이는 종(species)마다 550 bp (흰등멸구)에서 699 bp (겨풀멸구)까지 차이를 보였다. 같은 Nilaparvata 속의 겨풀멸구와 벼멸구붙이 사이 의 염기서열 차이 추정값(d ± S.E.)은 0.001 ± 0.001로 가장 낮았으며, 사슴멸구와 일본멸구 사이는 0.579 ± 0.021로 가장 높았다. 벼멸구와 다른 멸구류들 과의 종간 염기서열 차이 추정값은 0.056 ± 0.008 (겨풀멸구)에서부터 0.548 ± 0.021 (일본멸구)로 구분되었다. 반면, Neighbor-joining 방법으로 추론된 분자계통수에서는 겨풀멸구와 벼멸구붙이를 제외하고 나머지 멸구류들은 독립된 다른 그룹으로 분지되었다. 벼멸구의 ITS2 염기서열을 참고하여 벼멸구 특이 고리매개등온증폭(loop-mediated isothermal amplification, LAMP) 프라이머 4 세트(BPH-38, BPH-38-1, BPH-207 및 BPH-92)를 제작하였다. 이들 각각을 벼멸구, 흰등멸구 및 애멸구의 게놈 DNA와 65°C에서 60분간 반응시켰을 때, 벼멸구 시료에서만 증폭 산물들이 관찰되었다. BPH-92 LAMP 프라이머 세트로 65°C에서 벼멸구 DNA의 양(0.1 ng, 1 ng, 10 ng, 100 ng)과 반응시간(20분, 30분, 40분, 60분)을 달리하여 형광반응을 관찰하였을 때, 20분과 30분 반응에서는 100 ng 까지에서도 발광여부 구별이 어려웠다. 그러나 40분 반응에서는 10 ng 이상에서, 60분 반응에서는 0.1 ng 이상에서 발광여 부가 명확히 구별되었다.

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.

Three rice planthoppers, the brown planthopper (Nilaparvata lugens), the white back planthopper (Sogatella furcifera), and the small brown planthopper (Laodelphax striatellus) and the green rice leafhopper (Nephotettix cincticeps) are major homopteran sap-sucking rice pests in Korea. These insect pests commonly have highly modified mouthparts, the stylet bundle, for piercing and sucking. Two pairs of mandibular and maxillary stylets consist of the stylet bundle by interlocking each stylet, which forms the two canals, larger one for food canal and smaller one for salivary canal. Destructive damages result from direct feeding effects (hopperburing) with heavy infestation and/or transmitting virus diseases (Rice stripe virus and Rice black-streaked dwarf virus by L. striatellus and Rice dwarf virus by N. cincticeps). Damage level is closely related to the feeding behavior of sap-sucking insects, so generally honeydew excretion amount on the resistant rice variety is smaller than that on the susceptible. Therefore, the method to measure the honeydew excretion amount has been primarily used as an indirect way to compare the feeding amount between the susceptible and the resistant. On the other hand, the electrical penetration graph (EPG) technique was firstly developed by McLean and Kinsey (1964) to measure voltage changes during piercing and sucking of insect on the plant. Since specific voltage waveforms were identified and it was known that each waveform is commonly related to salivary and feeding behavior of insect stylets in the plant tissue, EPG technique has been used to real-timely and quantitatively measure feeding behavior of piercing and sucking insects on susceptible and resistant rice variety. However, identifying each different waveform distinctly and understanding biological function of each waveform are certainly necessary to analyze feeding behavior in the plant tissue such as phloem sap ingestion. In this study, the stylet penetration behavior of N. lugens, S. furcifera, L. striatellus, and N. cincticeps on rice plants (Oryza sativa) was evaluated through the use of a direct current based electrical penetration graph (DC-EPG). To accomplish this, we classified the EPG waveforms of planthopper group into seven different patterns, np, N1, N2, N3, N4-a, N4-b, and N5, according to their shapes, voltage amplitudes, voltage levels, and frequencies. The N4-b pattern was always preceded by N3 and N4-a, in that order. Continuous honeydew excretion only occurred during the N4-b period, and the honeydew deposited on a filter paper containing ninhydrin reagent during the N4-b period were stained into violet. Based on the location of the stylets in the cross-section of rice tissue and honeydew excretion, the EPG waveforms for the stylet penetration behaviors of the three rice planthoppers were assigned to the following groups; np: non-penetration of stylets, N1: penetration initiation, N2: salivation and stylet movement, N3: an extracellular activity near the phloem region, N4-a: an intracellular activity in phloem region, N4-b: phloem sap ingestion, and N5: activity in the xylem region. Futhermore, we classified the EPG waveforms of the green rice leafhopper, N. cincticeps into seven different patterns, Nc1, Nc2, Nc3, Nc4, Nc5, Nc6, and Nc7 according to their shapes, voltage amplitudes, voltage levels, and frequencies. The Nc6 pattern was always preceded by Nc5 pattern. The Nc6 pattern of the leafhopper was carefully considered as a phloem sap feeding behavior based on regular honeydew excretion. On the other hand, the planthopper group and the leafhopper hardly showed the phloem sap feeding pattern on resistant rice varieties during an EPG-recording. In addition, the duration of the phloem sap feeding patterns was highly decreased on resistant rice varieties relative to susceptible ones. From these results, it is suggested that the phloem sap feeding related patterns are an important parameter to determine resistance of rice plant.

해충의 발생시기와 발생량에 대한 정확한 예찰정보는 해충의 효율적인 종합적 방제를 위하여 필수적으로 요구된다. 해충의 효율적인 발생 예찰조사를 위해 디지털 영상처리 알고리즘을 이용하여 벼농경지에서 주요 해충인 멸구류를 자동적으로 인식하고 밀도를 측정하도록 하였다. 야외경작지에서 촬영한 입력영상에 대해 구성인자분해과정, 탑헷(top-hat)변환, 역치적용, 최소/최대 필터링 등의 방법을 적용하여 벼 잎에 붙어 있는 멸구 개체를 인식하고 개체수를 헤아렸다. 평균인식율은 95.8%를 보였다. 또한 인지된 각 멸구류 개체 크기를 측정하여 멸구류의 연령분포 추정을 가능하게 하였다

논에 설치한 유아등에 채집되는 멸구류를 비전문가들도 쉽게 동정할 수 있도록 인터넷에서 운영할 수 있는 하이퍼텍스트 기반의 검색표를 개발하였다. 그리고 정확성 검정을 위해 곤충 동정 경험이 없는 12명의 대학생을 대상으로 그 효용성을 평가하였다. 그 결과, 흰등멸구의 동정 정확성은 56%에서 83%로 증가하였고, 애멸구의 동정 정확성은 47%에서 80%로 증가하였다. 그러나 벼 멸구의 동정 효율을 높이는데는 충분하지 못한 것으로 나타났다.