루비깍지벌레 Ceroplastes rubens는 감귤에 피해를 주는 주요 깍지벌레 중 하나로 연 1회 발생하며 수액을 흡즙하는 직접적인 피해와 분비된 감로로 인한 그을음병 유발의 간접적인 피해가 발생하고 있다. 제주지역에서 루비깍지벌레 천적으로는 루비붉은깡충좀벌 Anicetus beneficus와 애홍점박이무당벌레 Chilocorus kuwanae 2종이 확인되었다. 1975년 일본에서 도입 방사한 천적인 루비붉은깡충좀벌이 현재까지 지속적으로 발생하고 있었으며, 루비깍지벌레 발생 억제에 영향을 미치고 있었다. 2018년 4월부터 12월까지 도내 유기재배 감귤원 (2개소)에서 황색끈끈이트랩을 이용 루비붉은깡충좀벌 성충의 시기별 발생양상을 조사한 결과 월동세대 성충은 5월 중순, 제1세대와 제2세대 성충은 각각 7월 중순과 8월 하순에 발생 정점을 나타내었다. 조사 포장에서 루비깍지벌레의 기생률은 9월 중순에 9.6%와 19.6%이었다.

Many herbivorous insects sequester plant defense compounds from their host plants to protect themselves from natural enemies. In plants, these defense compounds are often stored as protoxins separated from their activating enzymes. A well-known example is the glucosinolate-myrosinase defense system in plants of the order Brassicales. When plant tissue is ingested by herbivores, glucosinolates are hydrolyzed by the enzyme myrosinase to form highly reactive isothiocyanates. We previously reported that flea beetles of the genus Phyllotreta selectively sequester high amounts of glucosinolates from their crucifer host plants, and convergently evolved their own myrosinase which enables them to utilize sequestered glucosinolates for their own purposes (Beran et al., 2014). The presence of intact glucosinolates in these beetles suggests that despite tissue damage, ingested glucosinolates are not activated by the plant myrosinase. Rapid and efficient glucosinolate uptake from the gut lumen into gut epithelial cells can prevent hydrolysis and thus might be crucial to overcome this activated plant defense. We use the horseradish flea beetle Phyllotreta armoraciae as a model to study the molecular basis of sequestration in insects. In short-term feeding experiments, we showed that ingested glucosinolates are rapidly sequestered in the foregut. To identify the transporters that mediate glucosinolate import from the foregut lumen into gut epithelial cells, we focused on the MFS transporter family, which is known to transport a wide range of substrates. A phylogenetic analysis of putative MFS transporter sequences identified in P. armoraciae and other beetles revealed several specifically expanded clades in P. armoraciae. Out of 21 candidate genes that were heterologously expressed in Sf9 cells, nine showed glucosinolate transport activity in vitro. Interestingly, most candidate genes were exclusively expressed in the malpighian tubules, and two genes were additionally expressed in the foregut. We currently elucidate the function of these transporters in glucosinolate sequestration in vivo using RNAi. To better understand the function of sequestered glucosinolates, we performed bioassays with P. armoraciae larvae and the generalist predatory ladybird Harmonia axyridis. Upon predator attack, P. armoraciae larvae emitted high amounts of isothiocyanates and ladybird larvae stopped feeding within a few seconds and were highly irritated. However, silencing myrosinase gene expression in P. armoraciae larvae led to increased mortality compared to control larvae in survival assays with ladybird larvae. Our results demonstrate how Phyllotreta use plant defense metabolites to defend themselves against predators.

귤애가루깍지벌레는 감귤의 주요 깍지벌레 중 하나로 시설재배에서 피해가 심하다. 귤애가루깍지벌레는 밀집하여 발생하는 특성을 갖고 있으며, 귤굴나방이나 잎말이나방류 피해 잎에 기생하고 있어 약제 방제가 어려운 원인이 되기도 한다. 제주지역의 친환경 감귤원을 대상으로 천적곤충과 병원성 미생물을 조사하였다. 천적곤충은 기생성 천척은 Anagyrus sp. 1종과 포식성 천적은 혹파리 일종인 Golanudiplosis japonicus와 꼬마남생이무당벌레 Propylea japonica, 무당벌레 Harmonia axyridis, 풀잠자리 Chrysoperla carnea, 호랑풀잠자리 Micromus sp. 5종이었다. Anagyrus sp. 성충을 황색끈끈이트랩으로 연중 시기별 발생양상을 조사한 결과 5월 하순~11월 상순까지 발생하였으며, 귤애가루 깍지벌레 1세대 기간 동안 2회의 발생성기가 나타났다. 그 외에 곤충병원성 곰팡이 일종인 Paecilomyces sp.가 확인되었 는데, 주로 장마철에 자연발생되고 있었다. 귤애가루깍지벌레 생물적 방제를 위해 수입 천적인 Cryptolaemus montrouzieri (상품명: 깍지무당벌레)를 농가에서 구입하여 활용하고 있다.

춘천지역 농가 및 강원도농업기술원 내 시험포장에서 반촉성재배토마토(2~6월)에서 트랩을 이용한 주요 해충의 발생밀도와 천적 등을 이 용한 방제효과를 조사 하였다. 토마토 재배농가에서 주로 사용하는 약제와 유기농자재의 천적곤충에 대한 독성평가도 수행하였다. 반촉성재배 시 발생되는 주요 해충은 온실가루이(Trialeurodes vaporariorum)와 총채벌레류이었다. 온실가루이의 경우 4월 중순경부터 발생하기 시작하여 5 월 중순 이후 발생이 증가하였고, 총채벌레류는 4월 상순 경 발생을 시작하여 6월 이후에 증가하는 경향을 보였다. 저독성약제 선발시험을 통해 온실가루이와 총채벌레의 천적인 온실가루이좀벌과 미끌애꽃노린재에 대해 60% 이하의 독성을 보이는 살충제 1종(spiromesifen SC), 살균제 1종(cyazofamid SC) 및 님 추출물이 함유된 유기농자재 외 1종을 선발하였다. 이상의 결과에서 제시한 천적중심 관리모델을 적극적으로 활용한 다면 토마토 반촉성 시설재배 시 온실가루이와 총채벌레를 효율적으로 관리할 수 있을 것으로 기대된다.

Augmentative biological control, which refers to frequent releases of mass produced natural enemies, is well developedin the greenhouse cropping systems and many successful cases have been reported worldwide. The most robust biocontrolsystems are based on the principle of established populations of natural enemies before invasions of pests occur. However,the natural enemies that are commercially available do not establish well in all crops, which can be caused by a lackof food sources, a lack of oviposition sites or shelter, or because of an unsuitable microclimate. These problems can besolved by selecting new species of natural enemies that are better adapted to the crop and/or by providing the resourcesthat natural enemies need to survive and reproduce in the crop. Here we present some results of studies that may contributeto this “standing army approach” in biocontrol, based on the use of banker plants, nectar plants, rearing sachets, foodsprays and alternative prey applications.in the greenhouse cropping systems and many successful cases have been reported worldwide. The most robust biocontrolsystems are based on the principle of established populations of natural enemies before invasions of pests occur. However,the natural enemies that are commercially available do not establish well in all crops, which can be caused by a lackof food sources, a lack of oviposition sites or shelter, or because of an unsuitable microclimate. These problems can besolved by selecting new species of natural enemies that are better adapted to the crop and/or by providing the resourcesthat natural enemies need to survive and reproduce in the crop. Here we present some results of studies that may contributeto this “standing army approach” in biocontrol, based on the use of banker plants, nectar plants, rearing sachets, foodsprays and alternative prey applications.

귤나무속 과수의 주요 해충인 귤응애의 방제효과 극대화를 위해 괭이밥의 천적유지식물 적용 가능성을 검토하였다. 괭이밥을 지피식물로 조성한 처리구에서 일반 초생재배구에 비해 포식성 응애류 밀도가 평균 3배 이상 높게 나타났으며, 제초구에 비해 3.7배 낮은 귤응애 발생 밀도를 확인 할 수 있었다. 칠레이리응애는 괭이밥응애 알과 성충을 포식하지 못하였고, 사막이리응애는 일일 평균 괭이밥응애 알 1.96개와 암컷 성충 1.93개를 포식하였다. 온도 23 ± 1℃, 습도 70 ± 5%, 광조건 16L : 8D로 설정된 사육실에서 괭이밥응애 알에서 성충까지 17.4일이 소요되었으 며 77.5%의 부화율과 84.8%의 유충생존율을 확인하였다.

Negative effects of insecticides on non-target organism can be reduced by using selective and less toxic insecticides. We assessed the effect of subsequent application of flonicamid and Beauveria bassiana GHA on pests and natural enemies in soybean fields by recording their density in 6-8 d interval. Flonicamid controlled Aphis glycines Matsumura in 6 day after spray (DAS). Nymphs of Riptortus pedestris (F.) were also reduced by 46 and 48% in 12 and 19 DAS, respectively. Application of B. bassiana reduced R. pedestris nymph 50% in 16 DAS whereas adult R. pedestris, Medythia nigrobilineata Motschulsky and A. glycines were not significantly reduced in treated fields. Ladybird beetles, syrphid flies, hymenopteran wasps, and parasitism rate of R. pedestris eggs were not different between the treatment and control. These results suggest that flonicamid and B. bassiana showed less negative effect on the natural enemies and effective against aphids and nymphs stage of R. pedestris.

The house fly, Musca domestica L. is a serious cosmopolitan pest in livestock production systems. Poultry farmers employ various techniques to control them but rely heavily on the use of chemicals which has the serious drawback of the target pest becoming resistant. We have selected two native natural enemies in Gyeonggi area where selected for the biological control of the house fly. Carcinops pumilio (Erichson) (Coleoptera: Histeridae), commonly found in poultry manure, is an important predator of house fly eggs and larvae. The substitute food source was developed for the mass rearing of C. pumilio. Spalangia nigroaenea (Hymenoptera: Pteromalidae) not only parasitized the host to produce its progeny but also killed host pupae by feeding. The parasitoid induced mortality had an effect on the parasitoid-to-host density relationships.

Chemical communication is very important for survival and reproduction in insects. The successful survival of insects depends to a large extent on the ability to detect and recognize environmental signals. We can manage the insect pest populations by eco-friendly methods by understanding the chemical communication systems which lie among the host trees, pests, and natural enemies. Persimmon is the largest fruit tree in acreage in Korea. Many insect pests are attacking various part of persimmon. Major insect pests of persimmon in Korea are Riptortus pedestris, Halyomorpha halys, Plautia stali as hemipterans, Stathmopoda masinissa, Euzophera batangensis, Conogethes punctiferalis as lepidopterans, There are also some minor insect pests including Homona magnanima, Apolygus spinolae, Synanthedon tenuis, bark beetles et cetera. Some of these produce sex pheromones to attract conspecific females or produce aggregation pheromones to gather conspecific individuals. Interestingly, some insect pests are using the semiochemicals of other species, pheromones or floral scents, as kairomones to find hosts or oviposition sites. These relationships in chemical communications at persimmon ecosystem will be discussed using our research results and others so far.

Liriomyza leafminer flies comprise a pest group that causes both considerable economic losses and serious quarantine problems. To investigate Liriomyza spp. abundance and distribution along with natural enemies, we surveyed of leafminer (LM) species and its natural enemies (NE) on potato crop from 146 farmers’ field in the potato growing provinces during 2015. Sweeping (10 sweeps/ field) and visual inspection were employed within 5 minute-walking distance, and damaged leaflets (10 leaflets/ field) were collected in each field. Leafminer species were identified by morphological, and its NE was identified by morphological and molecular techniques. L. huidobrensis was the most dominant Liriomyza species. Distribution of L. huidobrensis on potato fields was expanding. Highest potato fields were infested with leafminer in southern parts of country. Highest rate (100%) field damage was recorded in Miryang, Namwon, Henam, and Boseong. Overall, NE species collected constituted of 4 families and 18 and 20 species in sweeping, and damaged samples respectively. There was a rich complex of parasitoid species including 20 species (13 species of Eulophidae family). The endoparasitoid, Braconid sp., Ganaspidium sp., and ectoparasitoid, Diglyphus isaea were dominant species in sweeping. While Diglyphus isaea, Hemiptarsenus varicornis, and the Braconid sp. were most dominant species collected from damaged samples. The number and diversity of parasitoid species in potato crop in Korea provides insight into the development of integrated control strategies of invasive LM pests in the field, and glasshouse crops.

Biological control as a tactic of environmentally safer agriculture has not been widely accepted by farmers. In Japan integrated biological control with native natural enemies is rapidly developing for greenhouse vegetables, because of high prices of commercially mass-reared biological control agents. We have studied the effective use of natural enemies at farm level, focusing on generalist predators, although there are differences in using natural enemies for augmentation in greenhouses and conservation in open fields. Recently, however, insectary plants (crops) have been considered as a key component for enhancing natural enemies. We have examined the effectiveness of candidate insectary plants on natural enemies and implemented biointensive IPM with insectary plants at farm-level. Our recent study suggested that some herbs and crops are highly effective on improving the survival and reproduction of generalist predators. By growing such plants in vegetable greenhouses and open-fields, natural enemy populations could be enhanced and thus stably persist even after targeted prey populations are exploited. Moreover, insectary plants may result in a shift of IPM from level I to level II.

This study was conducted to develop the biological insect pest control on pear orchard by using the native natural enemy from 2011 to 2013. We selected the green lacewing, Chrysoperla nipponensis (Okamoto) for useful natural enemy and developed the artificial mass rearing technique, and tested finally in pear orchard located in Anseong city. Nine species of insect pests including Pseudococcus comstocki on pear and seven species of natural enemies including C. nipponensis were investigated in Gyeonggi area. The optimum developmental temperature, humidity and photoperiod for C. nipponensis were 20 ∼25℃, 60∼70%, and 16L : 8D respectively. One C. nipponensis during larval stage could feed about 440 2nd nymphs of P. comstocki at 20℃. The more prey density increase, the more feeding amount C. nipponensis larva was increased. The eggs of almond moth, Ephestia cautella were useful as a substitute diet for natural enemy, C. nipponensis. Three commercial insecticides which registered as insecticide on pear shown the low toxicity to natural enemy, C. nipponensis will be suitable for integrated pest management (IPM) in pear orchards. C. nipponensis shown the about 80% of control value against the P. comstocki in field test when had committed from the early May to the early July. Controlling the P. comstocki by using of C. nipponensis, not only the 30% of yield was increased, but also the quality especially fruit sugar was increased.

Liriomyza leafminers comprise a pest group that causes both considerable economic losses and serious quarantine problems. In recent years, the pest status of Liriomyza sp. has changed in Korea, as well as other areas of the world. Potato field survey was conducted in 157 farmers’ field from five provinces during 2011 and 2012. Foliar insect monitoring was done within 5 minutes walking distance by visual inspection. Leafminer fly and parasitoids were collected by sweeping net (10 sweeps/field) in same field in each time. Overall, potato insect species collected constituted of 7 orders, 22 families and 42 species. Aphis gossypii was most abundant species in all the locations. However, Potato tuber moth, Pthorimaea operculella was only dominated species in Boesong (Jellanam-do). L. huidobrensis was the first record infesting the potato in Korea. Liriomyza huidobrensis was only found from Miryang (Gyeongsangnam-do) and Goreyong (Gyeongsangbuk-do). There is a rich complex of parasitoid species; 18 species of parasitoids were recorded. Most parasitoid species (11) belong to the Eulophidae family. The most abundant species were the ectoparasitoid, Diglyphus isaea and endoparasitoid, Ganaspidiumsp. The number and diversity of parasitoid species in potato crop in Korea provides insight into the development of integrated management strategies of leafminer pests.

 ,  , The effect of natural enemies on four major pests of hot pepper was tested in greenhouses. The aphids were successfully controlled by introducing three Aphidius colemani-banker plants, and releasing 23.3 wasps per m<, SUP>, 2<, /SUP>, on April 16 and 23 wasps per m<, SUP>, 2<, /SUP>, in a greenhouse of 660 m<, SUP>, 2<, /SUP>, . To control thrips, Orius laevigatus was released twice, 3.0 bugs per m<, SUP>, 2<, /SUP>, at a time(May 11<, SUP>, th<, /SUP>, and June 12<, SUP>, th<, /SUP>, ). The thrips population was controlled within 0.3 thrips per flower during the growing season. To control two species of mites, Tetranychus kanzawai and Polyphagotarsonemus latus, and the silverleaf whitefly, Bemisia tabaci, a total of 113.7 individuals of Amblyseius swirskii were released twice(May 11<, SUP>, th<, /SUP>, and 30<, SUP>, th<, /SUP>, ). The densities of B. tabaci and T. kanzawai were kept within 171.0 individuals/trap and 0.8 individual/leaf, respectively. P. latus was suppressed completely twelve days after release. The cost of the released natural enemies to control the four arthropod pests in this study was 420,000 Won per 660 m<, SUP>, 2<, /SUP>, .

 ,  , Effect of a new crop protectant ‘Bt-Plus’ on natural enemies was analyzed in this study. Tested natural enemies included two parasitic species of Aphidius colemani and Eretmocerus eremicus, and four predatory species of Harmonia axyridis, Orius laevigatus, Amblyseius swirskii, and Phytoseiulus persimilis. ‘Bt-Plus’ was formulated by combination of three entomopathogenic bacteria (Xenorhabdus nematophila (Xn), Photorhabdus temperata subsp. temperata (Ptt), Bacillus thuringiensis (Bt)) and bacterial metabolite (BM). All three types of ‘Bt-Plus’ showed significantly higher toxicities against fourth instar Plutella xylostella larvae than Bt single treatment. Two types of bacterial mixtures (‘Xn+Bt’ and ‘Ptt+Bt’) showed little toxicity to all natural enemies in both contact and oral feeding assays. However, ‘BM+Bt’ showed significant toxicities especially to two predatory mites of A. swirskii and P. persimilis. The acaricidal effects of different bacterial metabolites were evaluated against two spotted spider mite, Tetranychus urticae. All six BM chemicals showed significant acaricidal effects. The BM mixture used to prepare ‘Bt-Plus’ showed a high acaricidal activity with a median lethal concentration at 218.7 ppm (95% confidence interval: 163.2 - 262.3). These toxic effects of bacterial metabolites were also proved by cytotoxicity test against Sf9 cells. Especially, benzylideneacetone, which was used as a main ingredient of ‘BM+Bt’, showed high cytotoxicity at its low micromolar concentration.

Biological control of rice insect pest is an important component of an IPM program. There are many species of natural enemies which contribute to the suppression of rice pest populations below economic injury levels. In order to use biological control more efficiently, it is a need to identify beneficial species and determine their roles in possible regulation of insect pests. There is a rich complex of biological control agents in rice and bund. This research was carried out to investigate the population density of insect pests and natural enemies in the rice field and bund. A total of 7 pest species and 15 natural enemy species were collected in the rice field. 10 pest species and 20 natural enemy species were collected in the bund, also. Changes in population density of insect pests and its prey were investigated in the rice field and bund. Population densities of insect pests were low at any time during the rice growth period in the field. This could be the high density of natural enemies. Bunds served as refuge for natural enemies when rice maturity. There are rich complex of biological control agents in rice field and bund. So, when we practice integrated pest management(IPM) of rice insect pests, we should use various natural enemies.

This study reports the results of natural enemy application against four insect pests on greenhouse sweet pepper in winter cropping system. Orius laevigatus (3.3/㎡) was released at two different times (Nov. 2005 & Feb. 2006) to control Frankliniella occidentalis, western flower thrips (WFT). Throughout the cropping season, the lowest level recorded of WFT was less than 2.0 individuals per yellow sticky trap. Amblyseius swirskii (232.3/㎡) was released four times (Nov. 2007 ~ Aug. 2008) to control Bemisia tabaci, tobacco whitefly (TWF). Until July 2008, TWF population had been suppressed lower than 6.6/trap. Phytoseiulus persimilis (44.5/㎡) was released seven times (Apr. 2008 ~ Aug. 2008) to control Tetranychus kanzawai, tea red spider mite (TRSM). As a result, TRSM population was suppressed lower than 1.7/leaf. To control aphids, Aphidius colemani (9.5/㎡) was released seven times (Oct. 2004 ~ Jan. 2005), with the transplantation of banker plants (5.5pot/660㎡). As a whole, aphid"s population has been successfully reduced to less than 2.0/leaf.

We have investigated some biological characteristics, such as survival rate and fecundity, of Orius laevigatus and Phytoseiulus persimilis, which have been stored at 6, 8, 10, 12±1℃, RH 70±10%, in dark condition. Overall, an appropriate temperature for cold storage was 10℃ for O. laevigatus and 8℃ for P. persimilis. 70% of adult O. laevigatus could survive for 36 days at 10℃. The O. laevigatus stored at 10℃ for 10~50 days laid 37.1～120.5 eggs. Since fresh (no storage) O. laevigatus laid 224.5 eggs, comparative fecundity of stored adults was 16.5~53.7% of normal fecundity. P. persimilis stored at 8℃ for 7~42 days with (food eggs of Tetranychus urticae) laid 11.9～18.9 eggs. Since fresh P. persimilis laid 26.4 eggs, comparative fecundity of stored adults was 45.1~71.6% of normal fecundity.