말채나무공깍지벌레의 계절적 발육을 2019년 6월 4일(약충) 부터 2020년 6월 25일까지(1세대 약충) 경상남도 사천시 소재의 블루베리 과 원에서 관찰하였다. 본 충의 발육을 연구하기 위해서 2018년 눈에서 발아한 5개 이상의 잔가지를 1주 간격으로 농가에서 채취하였다. 깍지벌레의 발육은 실체현미경 하에서 조사하였고 화학적 방제는 시중에서 이용할 수 있는 3종의 살충제로 블루베리 과원에서 수행하였다. 발육기간과 유효적산온도(Centigrade Degree-Days accumulation, DDC)에 대한 결과는 다음과 같다. 산란기간(최성기): 2020년 5월 12 -26일(DDC, 110.0-188.5(173.6)); 부화기간(최성기): 2020년 6월 9 - 23(19)일)(DDC, 325.2-480.8(435.6); 난기간: 26 일; 월동성충으로부터 약충의 신엽으로 이동: 2020년 6월 16-25 일(DDC, 410,5 - 500.4); 성충으로 발육하기 위한 잎에서 잔가지로 이동(최성기): 2020년 2월 4 -18(8)일. 성충 한 마리 당 산란수(범위): 956.8 ± 73.4 (13 - 3497); 알의 크기(mm): 0.29 ± 0.020(L), 0.15 ± 0.013(W); 부화약충의 크기: 0.35 ± 0.018(L), 0.18 ± 0.007(W), 0.09 ± 0.007(눈 간격); 성충크기: 4.30 ± 0.893(L), 2.64 ± 0.520(W). 월동성충으로부터 부화한 약충은 신초의 잎 뒷면에서 다음해 2월 초순 잎이 떨어질 때까지 약 95%가 발견되었다. 이들은 2령충으로 월동하고 1년에 한 세대를 경과하였다. 기어다니는 1령충을 방제 하기 위하여 3종의 살충제를 7월 16일과 30일에 거북밀깍지벌레에 등록된 농도로 처리하였다. 아세타미프리드수화제가 1회 처리 21일 후에 96.9%의 사충율을 나타내었다.
단감원에서 식나무깍지벌레의 발생을 최소화하고자 시기별 발생특성과 우수 방제약제를 선발하였다. 가지에서 월동한 약충이나 암컷 깍지 는 9월 중순경에 교미 후, 월동에 들어가며 다음 해 봄철에 기온상승과 더불어 포란과 산란의 과정을 거쳐, 5월 중하순까지 산란을 마친 후 죽었 다. 수컷은 대부분 9월 말까지 우화하여 암컷과 교미하고 죽었으나 낙엽에서 월동하는 개체의 경우 모두 사멸하였다. 식나무깍지벌레의 산란 특 성은 매년 기상상황에 따라 차이가 있었고, 4월 중순부터 5월 중·하순까지 산란하고, 5월 초․ 중순에 산란 최성기를 보였다. 산란 량은 160개 정 도로 추정되며, 산란 최성기로부터 약 1주일 경과 후 부화 최성기를 보였다. 여름철에는 7월 초․ 중순에 시작하여 8월 중․ 하순까지 산란하고, 7월 말과 8월 초에 산란 최성기에 도달하며, 암컷 한 마리당 산란수는 봄철보다도 다소 적은 130개 정도이고, 난 기간은 약 4일로 추정되었다. 가는 가지에서 월동한 성충이 산란한 알로부터 부화한 1세대 약충은 가지와 잎에서 각각 10%, 90% 정도의 비율로 관찰되었다. 가는 가지에서 대부분 암컷 깍지로 발육하고 2009년 7월 27일 2세대 약충 발생 최성기에 도달한 다음 8월 중 ․ 하순경부터 월동처로 정하고 살아간다. 암컷과 수컷 깍지 는 8월 이전까지 잎에서 거의 비슷한 비율로 발육하다가, 2009년 8월 12일 이후 잎에서 수컷의 약충 발생 최성기를 시작으로 8월 27일 수컷 깍지 벌레 발생 최성기, 9월 14일 전후로 수컷 성충의 발생에 이르기까지 일관된 발생관계를 관계를 보여주었다. 8월 12일 잎에서 관찰되는 약충 중 75% 정도는 발육하여 수컷으로 우화하여 교미하고 죽는 것으로 나타났다. Buprofezine+dinotefurn (20+15) WP로 6월 9일과 16일 2회 방제 하고 7주 후에 생사충을 판정한 결과 방제가가 90.6%로 나타났다.
온실재배 오이에 발생하는 목화진딧물의 발생밀도를 추정하는 표본조사법을 개발하기 위하여 2개년(2013-2014년) 동안 주 전체의 잎별 발생밀도를 조사하였다. 목화진딧물의 공간분포 특성은 일반적으로 사용되는 Taylor’s power law(TPL)와 Iwao’s patchiness regression (IPR) 두 가지 방법을 이용하여 분포특성을 조사하였다. 목화진딧물의 주 전체 밀도를 대표할 수 있는 표본단위를 일정 잎 위치의 평균밀도와 주 전체의 잎당 평균밀도와의 일반선형 회귀식을 이용하여 결정하였다. 적정 표본단위는 오이 생육기에 따라 달랐는데, 총엽수가 9매 미만일 경우 2매(중위 엽과 최하위+1번째 엽), 그 이상인 경우에는 3매(위로부터 4번째, 7번째, 최하위+1번째 엽)를 조사하는 것이 적합하였다. 오이에서 목화진딧물의 공간분포 특성은 TPL과 IPR의 기울기가 모두 “1”보다 커 집중분포를 하고 있었으며, 진딧물의 평균-분산 관계를 TPL이 IPR보다 더 잘 설명하 였다. TPL의 기울기와 절편은 연차간에 차이가 없었으며, Green과 Kuno의 식을 이용하여 고정 정확도(D) 수준에서의 축차표본조사법을 개발 하였다. 목화진딧물의 축차표본조사법은 Green의 방법이 Kuno에 비해 더 효율적이었다. 목화진딧물의 일정 평균밀도를 추정하기 위해 필요한 조사 주수는 D값과 잎당 평균밀도가 낮을수록 증가하는 경향이었다. 표본조사를 중지할 수 있는 누적 진딧물 수는 D값이 낮을수록, 조사 주수가 적을수록 증가하는 경향이었다. 목화진딧물 잎당 10마리의 밀도를 추정하기 위해 필요한 조사 주수는 13주이었으며, 이 때 조사를 중지하기 위한 누적 진딧물수는 131마리이었다.
Tetranychus urticae was collected from greenhouse roses to monitor the development of acaricide resistance. Dose-mortality lines were estimated on 16 regional populations with 13 acaricides. For each acaricide, LC50s of the populations were plotted to check normality. LC50s of eight acaricides showed normal distribution and five others did not. An index of Ln (recommended dose/LC50 for each acaricide) checked the development of resistance to populations. The index is based upon recommended dose to control a pest stage and empirical LC50 got from serial dilution range for each pesticide. We tried to categorize acaricides by index due levels of effectiveness to mites: tebufenpyrad, fenpyroximate, bifenthrin, and fenbutatin oxide as non-effective acaricides with less than index 1.0, chlorpyrifor+bifenthrin and milbemectin as alert level placed between 1.0 and 2.0, acequincyl as caution between 2.0 and 3.0, and abamectin, cyflumetofen, bifenazate, chlorfenapyr+fulacrypyrim and propargite as effective over 3.0. We also tested the similarity of acaricide actions for choosing effective acaricides against resistant mites and of populations for resistance management. We could make several acaricides groups: group1 including abamectin, cyflumetofen, and bifenazate group 2 propargite and chlorpyrifos+bifenthrin group 3 chlorfenapyr and acequinocy and group 4 mibemectin, fenyroximate, and bifenthrin, by which we can suggest not to use acaricide within the same group to avoid the resistance development. Populations grouping would imply similar practices of acaricide use, so we can manage pesticide usage, effectively. Group A includes Gimhae 2, 3, 4, 5, Jincheon2, and Taean, and Group B includes Goyang, Gangjin1, Paju, Gangin2 and Namwon.
몇 가지 살충제에 대한 독성을 썩덩나무노린재를 대상으로 단감원에서 잔효독성으로 검증하였고 끈끈이 트랩에 유인된 뚱보기생파리 성충 을 대상으로 직접분무처리 방식으로 검증하였다. 썩덩나무노린재는 흑색유아등으로 채집하였고 뚱보기생파리 성충은 갈색날개노린재 집합페로 몬인 methyl-(E,E,Z)-2,4,6-decatrienoate을 사용해서 끈끈이트랩으로 포획하였다. 비펜트린수화제, 뷰프로페진・디노테퓨란수화제, 클로티아 니딘액상수화제, 디노테퓨란수화제, 티아메톡삼입상수화제 등 5종의 살충제 중에서 비펜트린수화제가 72시간 케이지 내 잔효독성 검정결과 썩 덩나무노린재에 대해 93.1%의 사충율을 나타내었고 여타 살충제들은 다양한 사충율을 보였다. 뚱보기생파리에 대한 사충율은 55.3~74.3%이 었다.
In order to achieve the optimized pest control, correct estimation of pest densities is a prerequisite to monitor pest damage and to provide efficient pest management plans. Parameters regarding diffusion (e.g., diffusion constant) and population size (e.g., growth rate) were estimated by using diffusion equation. The time series dispersal data of Whiteflies collected in greenhouse were used for modeling. Cross-correlation analysis was conducted to reveal the range and direction of pest population invasion. Sampling theory was further investigated regarding estimation of densities, and population dynamics of Whiteflies were discussed in two dimensions.
Accurate estimation of pest density is a prerequisite in achieving efficient pest management. An automatic pest detection system with image processing was installed on a robot to recognize brown marmorated stink bug (Halyomorphahalys) on leaves of paprika(Capsicumannuumvar.angulosum). The shape of pest was recognized and subsequently the robot arm was moved toward the leaves to spray pesticides. The detection system was efficient along with increasing population densities increased. The robot with image processing system was useful for estimating population densities in spatial and temporal domain efficiently.
An attempt was made to stimulate future research by providing exemplary information, which would integrate published knowledge to solve specific pest problem caused by resistance. This review was directed to find a way for delaying resistance development with consideration of chemical(s) nature, of mixture, rotation, or mosaics, and of insecticide(s) compatible with the biological agents in integrated pest management (IPM). The application frequency, related to the resistance development, was influenced by insecticide activity from potentiation, residual period, and the vulnerability to resistance development of chemical, with secondary pest. Chemical affected feeding, locomotion, flight, mating, and predator avoidance. Insecticides with negative cross-resistance by the difference of target sites and mode of action would be adapted to mixture, rotation and mosaic. Mixtures for delaying resistance depend on each component killing very high percentage of the insects, considering allele dominance, cross-resistance, and immigration and fitness disadvantage. Potential disadvantages associated with mixtures include disruption of biological control, resistance in secondary pests, selecting very resistant population, and extending cross-resistance range. The rotation would use insecticides in high and low doses, or with different metabolic mechanisms. Mosaic apply insecticides to the different sectors of a grid for highly mobile insects, spray unrelated insecticides to sedentary aphids in different areas, or mix plots of insecticide-treated and untreated rows. On the evolution of pest resistance, selectivity and resistance of parasitoids and predator decreased the number of generations in which pesticide treatment is required and they could be complementary to refuges from pesticides To enhance the viability of parasitoids, the terms on the insecticides selectivity and factors affecting to the selectivity in field were examined. For establishment of resistant parasitoid, migration, survivorship, refuge, alternative pesticides were considered. To use parasitoids under the pressure of pesticides, resistant or tolerant parasitoids were tested, collected, and/or selected. A parasitoid parasitized more successfully in the susceptible host than the resistant. Factors affecting to selective toxicity of predator are mixing mineral oil, application method, insecticide contaminated prey, trait of individual insecticide, sub-lethal doses, and the developmental stage of predators. To improve the predator/prey ratio in field, application time, method, and formulation of pesticide, reducing dose rate, using mulches and weeds, multicropping and managing of surroundings are suggested. Plant resistance, predator activity, selective insect growth regulator, and alternative prey positively contributed to the increase of the ratio. Using selective insecticides or insecticide resistant predator controlled its phytophagous prey mites, kept them below an economic level, increased yield, and reduced the spray number and fruits damaged.
Movement behaviors of specimens of mite (Tetranychus urticae) were computationally analyzed after the treatments of pesticide, abamectin, at a low concentration of 0.78ppb. During the observation period, test specimens were placed individually on the bean leaves (diameter=7mm), and their position was recorded in 2-dimension at 0.25 second intervals (8 hours before treatment and 8 hours after treatment). The selected parameters such as speed, angular change, meander, etc, were checked for characterizing response behaviors after the treatments. The difference of mite behavior was accordingly observed after the treatments, and the time spent in the center area appeared to be longer after the treatments. Additional characterization of movement behaviors was computationally checked, and utilization of behavioral monitoring in pest management was further discussed regarding early detection of susceptible or resistant strains.
Oriental persimmon, Diospyros kaki Thunb., endemic to East Asia is one of the major fruit crops in Korea. We conducted the faunal survey of mites on persimmon trees in Korea from June to September 2006, especially focusing on herbivorous and predacious mites. Mites of Tetranychidae and Tenuipalpidae were dominantly collected as herbivores, while those of Phytoseiidae and Stigmaeidae were predominant as predators. All identified tenuipalpid mites were Tenuipalpus zhizhilashviliae Reck. Most of the collected tetranychid mites were found to belong to the genus Tetranychus. To clarify the species identity, additional collections of tetraychid mites during summer 2007 on sweet persimmon were made. The mites were identified as Tetranychus urticae Koch. Four phytoseiid species, Neoseiulus womersleyi (Schicha), Amblyseius eharai Amitai and Swirski, Phytoseius (Dubininellus) rubii Xin, Liang and Ke and Typhlodromus (Anthoseius) vulgaris Ehara were collected. Among them, A. eharai was the most dominant species.
Seventeen populations of two spotted mites (TSM) were observed 3 times per month from May to October to figure out their fluctuations at the site of individual farmer’s orchard from Sacheon, Sancheong, and Jinju in Gyeongsangnam- do and Gwangyang, Gurye, and Suncheon in Jeollanam-do. Among them, only 2 sites were properly managed, 5 sites were required to control but the farmers had little information on the mite and its damage, though 10 orchards were not in jeopardy. Number of TSM reached more than 400 at its maximum when 100 leaves were randomly observed at orchards from Sacheon, Okgok, and Muncheok, showing remarkably discolored leaves.
For the control of TSM in fields by chemical means, it was tried to select an effective miticides in persimmon fields. Control activity of spiromesifen 20SC showed 99.0% and 98.1% and the activity of acequinocyl 15SC showed 90.8% and 99.0% in Jinju and Sacheon at 20 days after treatment, respectively.
It was tried to understand the cause of the fluctuations of TSM populations on the viewpoints of pesticide spray, density of predacious mites, rainfalls, and weeds in the persimmon orchards. Various factors considered to contribute to the cause of population fluctuations, depending upon the situations of each orchard.
To develop as a potential resource of biological control agents, it was tried to find out winter spatial distribution and movement of Amblyseius eharai (Acari: Phytoseiidae) on persimmon trees in Korea using artificial materials. We attached Phyto traps and urethane foam on persimmon trees in early November 2007 in Sacheon, Korea to estimate overwintering ecology of the predominant phytoseiid species Amblyseius eharai on persimmon. Most of A. eharai were found on the samples of branches, such as pedicel. In early spring, A. eharai was abundantly collected in the weekly and long-term traps before the leaf extension of persimmon trees, which additionally enhanced the possibility that A. eharai overwintered on the trees.
Accurate estimation of insect density is essential for effective pest management. A simple robotics and image processing system were combined to automatically recognize the density of whiteflies. Subsequently the robot arm was utilized to spray the pesticides in the area of infestation in a minimized amount. The estimated densities of samples in the laboratory condition were in accordance with the actual values. The detection system was efficient when the whitefly densities were at medium to high levels. The results of the present study indicate that the robotic and image processing integration system described here would be useful for evaluating the population dynamics.
As suggested by Kawashima (2006), the most abundant Tetranychidae was Tetranychus sp. as a pest in persimmon orchards. The observatory orchards were selected 16 in total, 2 from Gurye, 2 from Gwangyang, and 2 from Suncheon in Jeonnam Province and 3 from Jinju, 4 from Sacheon, and 3 from Sancheong in Gyeongnam Province. Number of mites in 100 persimmon leaves were observed from each orchards nearly every ten days. Careful rearing of the mites sample collected from the four observaory persimmon fields at which the mite had occurred the most seriously among 16 fields and results from taxanomical identification process indicated that the species was identified Tetranychus urticae. Maximum number of T. urticae reached to 436 on 27 June at Jeongdong, Sacheon, 108 on 1 August at Sinann, Sancheong, 406 on 26 June Okgok, Gwangyang, and 509 on 15 June Muncheok, Gurye. When the number reached to more than 400 mites, the persimmon leaves changed from clear yellow dots, to pale yellow, and to grey in the backside. An experiment was conducted to control T. urticae and to select highly active miticide in persimmon orchards in Jinju and Sacheon. Spiromesifen 20SC and acequinosyl 15 SC were effective.