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.

DNA ‘barcoding’ has potential applications in insect pest monitoring and quarantine since large numbers of DNA sequences for insect species identification have been reported in recent years. However, the exact number of relevant COI sequences in public databases such as NCBI (http://www.ncbi.nlm.nih.gov/) is not readily available. The IMGD (Insect Mitochondrial Genome Database; http://www.imgd.org) contains 162,847 partially sequenced mitochondrial gene entries originated from 35,067 hexapod species and makes it possible to check whether DNA sequences have been previously reported or not for certain insect species. In this study, we applied the IMGD to establish baseline data for the forest pest insects in Korea, before constructing a DNA barcode system. Retrieving data from the IMGD, we recognized that DNA sequences were already available for 73 of 259 species known as forest pest insects in Korea. Most of the 73 species with DNA sequences are common pests worldwide but there maining 186 species are endemic to the Eastern Palearctic region. Based on these data, we are proceeding to construct a Korean Forest Insect Pest DNA barcode database.

Dynamics of prey/host and predator/parasitoid interaction has been the main concern of the population ecology during the second half of the 20th century. Many theoretical and experimental studies have been conducted and discussed. The main questions were whether the interaction could be in stable state and whether the parasitoid/predator could regulate the host/prey populations, and if so at what levels. The questions are not yet solved, but some hypotheses have been presented that the prey/predator interaction could be in stable state, when both the predator and prey population are under intraspecific competition so that both populations could be limited at a low levels. This prerequisite, however, could not be easily satisfied in nature and several hypotheses have been discussed up to date. Biological control of pests, which is based on the predator-prey system dynamics, has not always been successful, because we do not understand the systems sufficiently. Thus, most successful cases of the biological control were dependent upon ‘trial and error’. But as the predator-prey system dynamics could be well understood in the future, more systemic control program of biological control could be possible. In this review, we analyzed the studies for biological control of pests in Korea based on 164 cases reported in the last forty years and will consider the future goal of the studies for more reliable control programs.

In this study, 5 species (Tetranychus kanzawai Kishida, Endoclyta excrescens (Butler), leaf roller caterpillar (Adoxophyes orana Fisher), Anomis mesogona (Walker), and Aulacaspis rosae (Bouche)) were found in Rubus coreanus Miquel in Jeonbuk province, from 2006 to 2008. T. kanzawai appeared in mid-May and showed three peaks in late June, mid-July, and late August. Its density was over 10 adults per leaf. A. mesogona appeared in mid-June and showed two peaks in late July, and early October. Of the 28 insect pests in pre-harvesting, the 7 main species were T. kanzawai, T. urticae, A. orana, Lygocoris lucorum Meyer, Frankliniella intonsa (Trybom), Psylliodespunctifrons Baly and Motschulskyia serrata (Matsumura). Of the 19 insect pests in after-harvesting, the 6 main species were T. kanzawai, E. excrescens, A. mesogona, A. orana, P. punctifrons and A. rosae. Growth of R. coreanus decreased when insect pests were not managed and yields decreased approx. 7% a year. Management of insect pests in field using pesticide was not different.

On the development and reproduction of four major agricultural insect pests including B. tabaci, M. persicae, P. xylostella and T. urticae, electron-beam was irradiated with different doses of 30, 50, 70, and 100 Gy. The effect of electron beam was investigated with respect to the longevity, egg hatching, emergence, and fecundity. Eggs hatching of B. tabaci, P. xylostella and T. urticae were more inhibited as increased irradiation doses. Especially B. tabaci and T. urticae eggs were perfectly inhibited to hatch at a dose of 100 Gy. However, these pests showed no lethal effect on the nymph/larva, pupa, and adult stages. When irradiated on the eggs of B. tabaci, P. xylostella and T. urticae, the emergence was inhibited from nymphs/larvae to adults. Individually, B. tabaci emerged adult did not lay eggs at a dose of 70 Gy. Besides, fecundity of P. xylostella emerged adult decreased at a dose of 100 Gy. On the contrary, irradiation did not affect the longevity of P. xylostella adult. When irradiated on B. tabaci, P. xylostella, Myzus persicae and T. urticae nymphs/larvae, emergence was inhibited at doses of 70 and 100 Gy, and decreased the fecundity and inhibited the hatching of laid eggs. However, the longevity of adults did not affect

The toxicity of methanol extract from 28 plants toward four agricultural insect pests were examined using contact toxicity bioassay with spray methods. At a concentration of 1,000 ppm Achyranthes japonica whole body was observed strong activity against Myzus persicae. Paeonia lactiflora root and Corydalis turtschaninovii rhizome methanol extract were observed strong activity toward Tetranychus urticae. Catalpa ovata leaf and Ginkgo biloba leaf and stem methanol extracts were revealed high activity toward Nilaparvata lugens. Actium lap root methanol extract was observed moderate activity against Plutella xylostella. High or moderate insecticidal activity of plant extracts were listed in Fig.1. These plant resource, particularly plant methanol extract or insecticidal constituents, merit further as potential insect pest control agents or leads because of their great activity as a insecticide.

Biological-control-based-integrated-pest-management of major pests occurring on sweet pepper in greenhouse during summer season was tried. As many as 2.1 Orius laevigatus per ㎡ were released in two times on June 6 and 19, and the population of thrips was kept under control and accordingly the damage was negligible throughout the season. To control aphids, a total of 0.8 Aphidius colemani per ㎡ were released in four times, 0.2 of them at a time, flonicamid on May 14 and July 18 and pymetrozine on June 14 and September 4 were sprayed on the spots of high aphid occurrence to reduce the release of the wasp, and the density of aphids was kept under control. Whitefly was controlled successfully by releasing a total of 343.4 Amblyseius swirski per ㎡ in nine times, 38.1 of them at a time, from May 9 until November 12 and dinotefuran was sprayed on November 12 when the density of whitefly increased up to 200 per trap. Tetranichus kanzawai was controlled by both Phytoseiulus persimilis which was released a total of 44.4 per ㎡ in five times 8.9 of them at a time from May 23 to September 10, and the A. swirski which was released for the control of whitefly.

Methyl bromide (MeBr) which is widely used in most of the countries for quarantine purpose, has been designated and under control as ozone depleting substance. This study is on the toxicity of ethanedinitrile as a MeBr alternative to control several wood-related insect pests. LC50 value of Ethanedinitrile(EDN) for Reticulitemes speratus, Tomicus piniperda adults at 21℃ was 0.26, 4.83 mg/L respectively. LC99 value of EDN for R. speratus at open status and closed wooden cubes was 0.65, 0.62 mg/L respectively, whereas MB was 13.96, 31.10 mg/L, which means that the toxicity of EDN for R. spratus is greater and EDN penetrates better into wood as compared with MB. The morality of EDN 20.3 mg/L(6hr) at 25℃ for Crytogenius lutats in wood was 90.3% in larvae, 58.6% in pupae and 89.5% in adults, which means that pupae were more resistant than larvae and adult. All stages of C. lutats were disinfected with EDN at or more than 29.9.mg/L, 6hr(CT product 89 mg hr/L) at 25℃. In sorption and application test, CT product of EDN 50 g/㎥(6hr) was 157 g hr/㎥ in the conditions of 21% wood moisture content with 25% loading, 171 g hr/㎥ in 54% wood moisture content with 25% loading and 158 g hr/㎥ in 54% wood moisture content with 50% loading, respectively. In all treatments, adults of Cryphalus fulvus and R. speratus were completely killed. The minimal CT product (158 g hr/m3) of 6hrs treatment was higher than CT product to disinfect C. lutats (89 mg hr/L). It is expected that it can be used as alternative fumigant of MeBr for woods.

In organic agriculture, various cover-crops have been used to control weeds. In this study, we have investigated the effect of Vicia tetrasperma (L.) Schred. (Eolchigiwandu) which is native to on major insect pests of pepper. Redpepper seedlings at 8 leaves stage were transplanted in 20th May 2009 into experimental field located in the farm of the department of agricultural biology, Suwon, Korea. A cover-crop cultivation plot was compared with a control plot mulched by black plastic-film. Density of aphids and damaged fruits by oriental tobacco budworm, Helicoverpa assulta, were surveyed ten times from 21 days after transplanting (DAT) to 82 DAT. Fifty and forty pepper plants were sampled to count the density of aphids and damaged fruits by oriental tobacco budworm per a plant, respectively. In current study, three aphid species namely, cotton aphid, Aphis gossypii, green peach aphid, Myzus persicae, potato aphid, Macrosiphum euphorbiae were collected. Overally, the density of aphids on pepper in the control plot was higher than the cover-crop plot. Especially, aphid density increased up to 67.44±26.8 in early stage of control plot, whereas aphid was not found in cover-crop plot. The rate of fruit damage by oriental tobacco budworm was significantly higher in the cover-crop plot than the control plot in early stage of pepper, however damaged fruit rate of pepper in the control plot was significantly higher since the middle of July.

The devastating insect pests of the tomato (Lycopersicon esculentum) were surveyed in environmentally friendly (no-pesticide and organic) greenhouses located in the provinces of Gyeonggi, Gyeongsang, Gangwon, Chungcheong and Jeju. Whitefly, leaf miner, aphid and moth were recorded as the major pests in these surveys. Among them, whitefly was the most serious pest of greenhouse cultivated tomato and major species was Trialeurodes vaporariorum. The population densities of T. vaporariorum was 0~36 nymph per leaf. Population of moths Spodoptera litura were the highest in summer season. Population of the whitefly was considered to be influenced by the previous cultural methods. Farmers in organic cultivation, used insect natural enemy, commercial EFAM (Environment Friendly Agricultural Material), yellow sticky trap or home made pesticides. Commercial microbial pesticides were applied to evaluate their insecticidal activities against whitefly. The results revealed that microbial pesticides exhibited 65.3 to 100% whitefly nymph mortality. Further, pesticidal activities of Cooking Oil and Yolk (COY), plant extracts and neem oil were evaluated against other tomato pests as well.

Global warming is one of the most buzzing words these days, as the average temperature increased up to 6.4℃ before the end of 21st century and the water level to 59cm causing severe draught, heavy snowfall, and monster typhoon all over the world. The capacity of natural ecosystem will not be able to contain such changes. Many of the species will be endangered and some of them are warned to be extinct, and accordingly water and food supply will not meet the demand of human. In 2007, IPCC, Inter Governmental Panel on Climate Change, made fourth report about global warming and estimated that the CO2 content in the atmosphere increased about 1.35 times to 379ppm at 2005 from 280ppm before the industrialization period pulling the average air temperature up by 0.7℃ a year. The water level as well increased by 1.8mm a year as the polar iceberg and permanent snow melt down. Global warming caused by environmental pollution and greenhouse gas may lead to the increase of price of not only agricultural product but also the industrial products as a consequence, a phenomenon so called Ecoflation, Ecology+inflation. IPCC forecasted that if the present phase use of fossil energy continues the air temperature in 2090-2099 will increase by 4℃ and the water level by 26-59cm compared to that of 1980-1999, warning particularly that the average increase of global temperature by 1.5-2.5℃ a year will put the species of 20-30% into danger of extinction. According to the report by the Korea National Statistical Office about the effect of climate change on the production of agriculture and fishery, the cultivation area of apple which is typical temperate fruit decreased to 29,204ha in 2007 from 52,447ha in 1992. On the other hand the cultivation area of peach increased greatly to 15,014ha(2005) compared to 12,000ha in 1996 as it became possible to grow wherever in Korea. Similar change can also be found for orange and grape, orange can be grown in Jeonnam and Kyuongnam province, and grape in Kangwon province. Jeju island and southern coastal area of Korea worry about the inhabitation of subtropical pests when they invade these area, in fact the pest outbreak as a result of the increase of generation a year is ever more frequent. The typical examples are Paratlanticus ussuriensis (Uvarov), the lantern fly, Lycorma delicatula, and the fruit moths like Carposina sasakii Walsingham.

This study was conducted to develop environmentally friendly control techniques to reduce chestnut insect pests. The study sites were selected in intensive chestnut orchards of Jinju city, Gyeongnam province. In early and middle-ripening cultivars of chestnut tree, the damage of chestnut fruits by Dichocrocis punctiferalis was significantly lower in wromstop than other treatment such as wromstop+wood vinegar, Capture-machine (p<0.05), While there was no significant difference among treatments in late-ripening cultivars. The hight control effect for D. punctiferalis was showed the highest in wromstop treanment with 40.49% and 41.89% in early and late-ripening cultivars. The control effects for Curculio sikkimensis in late-ripening cultivars of chestnut tree were 34.59% in wromstop imidacloprid treatment and 28.94% in air control treatment.

Three lepidopteran insect pests of the legume pod borer, Maruca vitrata (Lepidoptera: Pyralidae), the soybean pod worm, Matsumuraeses phaseoli (Lepidoptera: Tortricidae) and an Ostrinia spp. (Lepidoptera: Pyralidae) attacking adzuki bean, Vigna angularis, were confirmed as the major insect pests during the reproductive developmental stage of adzuki bean, and M. vitrata existed dominantly. Almost all plants in the adzuki bean field were in jured by at least one of the three species, and 15~60% of reproductive organs were injured. Unbloomed inflorescence occurred continuously through the reproductive stage of adzuki bean. While the flower was many at the early stage and its number soon decreased, the pod was few at the early stage, but its number increased soon and maintained at a constant level. The results suggested that the adzuki bean injured by insect pests compensate the flower loss by developing new inflorescence, but the compensation do not cause the development of new pods. While M. vitrata and M. phaseoli were observed in flowers, pods and stem mainly during the first half of reproductive stage of adzuki bean, Ostrinia spp. was observed only in pods and stem during the second half. In addition, while all instars of larvae of M. vitrata were observed, larvae between the third and fifth instars for M. pahseoli and Ostrinia spp. were observed.

The seasonal occurrence of insect pests in watermelon cultivated in greenhouses was surveyed in Gochang from 2006 to 2007 considering three seasonal types of culture: forcing culture, semi-forcing culture and retarding culture. Aphis gossypii, mites (Tetranychus urticae+T. kanzawai) and Palpita indica were the most serious pest species in watermelon greenhouse culture. A. gossypii and mites showed high density during the months of June and September in semi-forcing and retarding culture, respectively. Palpita indica was observed only in retarding culture. Leaf damage by Palpita indica was observed from the middle of August and peaked to 79.4% damage in the middle of September. Thrips and whiteflies were captured in high density by the yellow sticky trap in semi-forcing culture and retarding culture but these insects showed low population density in watermelon leaves.

A new Bacillus subtilis isolate showed high anti-fungal activities (more than 80% control efficacy) against several plant diseases such as rice blast (Magnaporthe grisea), tomato gray mold (Botrytis cinerea), tomato late blight (Phytophthora infestans) and wheat leaf rust (Puccinia recondita). We tried to confer an insecticidal activity to this B. subtilis isolate for constructing a recombinant strain which has dual functions, anti-fungal and insecticidal activity. The insecticidal cry1Ac gene of B. thuringiensis was constructed under its own promoter in a minimal E. coli-B. thuringiensis shuttle vector (pHT1K-1Ac). The plasmid, pHT1K-1Ac was introduced into B. subtilis isolate by electroporation and the transformant was confirmed by PCR with cry1Ac specific primers. B. subtilis transformant produced a parasporal inclusion in the cells as in B. thuringiensis and the size of that protein was appox. 130 kDa. The insecticidal activity of the transformant was checked against lepidopteran pest, Plutella xylostella. This result suggests that this recombinant B. subtilis strain shows the possibility of controlling harmful insect pests as well as plant fungal diseases simultaneously at one crop, and both culture broth and harvested cells of this strain can be used as individual biological control agents separately for integrated crop protection.

Road-map for the environmental friendly integrated pest management (IPM) of insect pests was drawn up on the strawberry vinyl-houses of farmer’s field. Major insect pests were occurred Tetranychus urticae and Aphis gossypii during the strawberry plant seeding in the vinyl house and open field. Also, same insect pests were occurred in the vinyl house during harvesting season of strawberry. For the control of T. urticae and A. gossypii, Phytoseiulus persimilis and Aphidius colemani as natural enemies were input to the vinyl house, respectively. However, because these natural enemies could not control insect pest populations, acaricide and insecticide were sprayed. Then natural enemies were input again in the vinyl house. Natural enemies could not endure the intense cold and differences of temperature and relative humidity between day and night during strawberry harvesting season. So, their behavior and control activity of pests were more decrease than pests. Firstly, natural enemies are input in the vinyl house during the early breeding season of strawberry, secondly, acaricides and insecticide are sprayed for the control of mites and aphids, respectively, during the middle breeding season in the hard winter. Finally, natural enemies are re-input in the vinyl house during the middle and late breeding season.