Many insects overwinter in diapause in the temperate region. Winter diapause often terminates far yearly than our thought, eg. Many in December. After diapause termination, insect becomes in quiescence. The lower developmental threshold of overwintering Oriental fruit moth larvae is in the range of 7.5-8.4℃ depending on the geographic location. We have determined the developmental period of overwintering OFM larvae from the time series interval collection. Collections were made from mid Jan to late March at 10d interval. Collected larvae were held in a cold chamber at 6°C for 5 days, and then subjected at 20°C with 75% R.H., 16:8(L:D).hr. The developmental period from overwintering cocooned larvae to adults was longest in mid. January collections, became shorter after 31 Jan. collection, then gradually decreased until mid March. Cocooned larvae developmental period became shorter after 31 Jan. while that of pupae became shorter after 20 Feb. During this study, female ratio was not different to 0.5. Mortality of winter collected larvae to adults was 45% including 30% parasitism. Partial explanation of the insect development under the lower developmental threshold was discussed; limitation of linear model estimation, temperature data quality and physiological metabolism after diapause termination. From January to February, daily average temperature fluctuated but under the lower developmental threshold. However, daily maximum temperature became noticeably higher than the lower developmental threshold after 20 Jan. However, this result indicates that after late Jan, physiological state of OFM is altered.

Understanding the spatial pattern of G. molesta and the temporal variation of their patterns are important to develop and maintain pest management programs in fruit orchards. The overwintering larvae of G. molesta pupate early in the spring and new adults begin a flight for several reasons such as mating, seeking resources (food or shelter) and oviposition. It was known that G. molesta presented “low movement activity” and male G. molesta flight behavior was closely related to the proximity of its host crops. Unmated males remain near the site of emergence in order to find and copulate with unmated females. The fruit-bearing status of orchards are important factors for G. molesta movement. To elucidate the spatial distribution and temporal variation of G. molesta within and among orchards, pheromone traps targeting male G. molesta were used because the trap represent a reliable and economic tool for monitoring adult G. molesta populations. The study was conducted in two apple orchards (one is isolated from other fruit orchards and another is surrounded by apple orchards), Andong and in seven plum orchards, Uiseong, 2010. Using spatial analysis by distance indices, the spatial pattern of G. molesta in each sampling date was presented. In the study of the spatial pattern within apple orchard, the index of aggregation (Ia) of isolated orchard were presented >1, indicating an aggregated distribution pattern, from monitoring results. The spatial association between successive monitoring using X (the index of spatial association) was negative during spring season and after then the value was changed to positive. In the experiment of the spatial pattern among orchards, the index of aggregation was >1 in most monitoring date and the index of spatial association was negative during early and late growing season. Factors influencing the spatial-temporal dynamics of G. molesta are discussed.

Grapholita molesta, G. dimorpha and C. sasakii as “internal feeders” are important apple pests in Korea. Three species overwinters around and in apple orchards. New young larvae of three species bore into new shoots or fruits and then feed inside apple. When mature larvae escape from fruits they make holes that reduces the commercial value of fruit. Therefore, understanding the phenological distribution of three species is critical to establish the precise management system for reducing three species population. The study was conducted to investigate the adult emergence of G. molesta, G. dimorpha and C. sasakii using pheromone traps and to forecast the cumulative proportion of each population. This study is second part of consecutive experiment. Data collection was carried out on three commercial apple orchards and one experimental orchard of Giran in 2010 and 2011. The experimental process was same in the study of plum. More than 50% of G. molesta male was occurred in spring season (within 500 degree-days), 2010 and 2011. The adult emergence of G. dimorpha and C. sasakii was linear and sigmoidal pattern in each year. The phenology of C. sasakii was explained well by nonlinear functions and the equation 3, 6, 8 and 11 were selected based on AICc and BIC. The selected equations were validated by the data of present year (2011) in each region. The performance of G. molesta and G. dimorpha was analyzed well by bimodal functions. The importance of phenological model is discussed to develop and maintain a more precise system for multiple pest management on apple orchard.

The study was conducted to investigate the phenological distribution of G. molesta, G. dimorpha and C. sasakii and to estimate the emergence timing of three species in plum orchards. It was known that G. molesta and G. dimorpha are a multi-voltine insect and C. sasakii has one to two generations depending on temperature and geographic location. Three species damage to many economically important fruit tree such as plum, pear, peach and apple. The main emergence time of each species is different depending on host plant and environmental conditions, specially temperature. Therefore, if we have the information of population density and low temperature threshold of a species and air mean temperature of a region in previous year we can predict the phenology of a species in present year. This is one part of consecutive research. Data collection was carried out in seven plum-growing commercial orchards of Uiseong in 2010 and 2011. The commercial pheromone monitoring traps (GreenAgroTech) were used to investigate the flight phenology of three speices. The record of temperature was received from meteorological center close to monitoring orchards. The relationships between degree-day accumulated above the low temperature threshold and cumulative proportion of accumulated moth caught of previous year was used to predict the phenology of three species in present year. The results of G. molesta and G. dimorpha estimated by bimodal functions were better than those analyzed by nonlinear functions. The phenology of C. sasakii was analyzed well by nonlinear function and the equation 3, 6, 8 and 11 were selected based on AICc and BIC. The selected equations were validated in each orchard.

Mungbean is an important crop in Nepal. Heteropteran bugs, Nezara virudula, Dolycoris baccurum, and Melanacanthus scutellaris are significantly influencing qualitative and quantitative loss in soybean and mungbean. Though pesticide application is common practice for management of these bugs, pesticide avoidance by the bugs stalls proper management. As an alternative, trap cropping with variety mostly preferred by the bugs as trap crops along with the main crop is considered. Selection of most preferred mungbean variety was performed with six (VC 6173 A; VC 6153 B-20G; VC 3960 A-88; Kalyan; Pratikchha; Saptari local) relative to Saptari local variety. Significant difference was recorded in number of bugs occurrence among the six varieties with maximum number of bugs in VC 6173 (3 bugs/plant) which showed lowest yield. For application, three different trap crop designs were employed in the field. There was significant difference between the main crop i.e. variety Pratiksha and the variety VC6173A used as trap crop in two designs. In conclusion VC6173A is a probable trap crop and the two designs can be employed in the field.

The study investigated the chemical treatment effects on apple borers (Lepidoptera: Totricidae, Carposinidae) when the larvae already bored inside the apple fruits. Infested apple fruits were harvested from the insecticide-free orchards in Giran, Andong on 17 July, 2010. Twenty chemical pesticides registered for the apple borers were treated on recommendation dose with dipping methods. Each treatment consisted of 20 infested apples with average 6.2 larva per apple. Mortality was relatively low, mostly 10% and a few with 30~40%. No larva died inside the apple. But dying larva escaped from apple much earlier than live ones. However there was significant sublethal effect.. Escaping time (d) from chemical treatments was longer than that from control where no chemical was treated. After escaping from the apple, in took ap. 2days to become pupae. Pupal periods were ap. 12 days without any difference among treatments. However adult emergence rate was higher in control (10.7%) than in treatments (18.5%). Among survived adults, one third was Carposina sasakii and remaining was Grapholita molesta. On conclusion, timing of insecticide spray is critical in the apple borer management.

Pollinating insects function significantly in structuring ecosystem as well as agricultural production. Among the variety of pollinators, Osmia cornifrons is one of the important pollinators in apple orchards. Unlike honey bees, O. cornifrons is able to pollinate at low temperature that facilitates its wide commercial use. The female O. cornifrons in nature lay their eggs to the interior of the bamboo reeds where they spend their larval and pupal stage throughout the summer and during fall they overwinter as adult. The adult bee emerges from the overwintering cocoon in the spring seasons. Since the complete synchrony with flowering period is critical, farmers collect and store the dormant state of O. cornifors in cold storage and expose them in due time to outdoor temperatures for their emergence, pollination activity can be performed. However, information on biological and ecological requirements for the emergence of overwintering adults are rarely reported. We carried out the experiments on temperature dependent adult emergence and constructed the emergence model based on developmental rate and distribution. Parameters were estimated from linear model and weibu

Apple borers such as oriental fruit moth (OFM) Grapholita molesta (Busck) (Lepidoptera: Totricidae), and peach fruit moth Carposina sasakii Matsumura (Lepidoptera: Carposinidae) can reduce the yield and its quality if not managed properly. Even peach fruit moth infestation in harvested apple could produce quarantine problem in exportation. We investigated the temporal distribution of apple borers infestation in an apple orchard where the infestation level of fruit was around 95% from September to early December, 2010. Every week, 150 apples were harvested from the apple orchard in Giran, Andong, Korea and 50 apples were cut to monitor the number of larval infestation. At the same time another 100 apples were kept in plastic container inside and outside the laboratory 50 each to check the escape of the infested larvae for overwintering cocoon formation. All larvae collected were identified based on the morphology and also verified by DNA sequence. The study indicates that the numbers of the infested larvae increased from September to October second week and then slightly decreased until early December with similar number of holes per apple. The holes produced by the escaping larvae were mostly found on dorsal side of the apple, but less on basal portion. Most of the infested larvae escaped from apple during late October to early November. Based on morphological characters such as anal comb, crocket and pupation shelter, the collected larvae were identified. 42.31% of larvae were G.molesta, 52.59% of larvae were C.sasakii and 5.10% were other species not identified.

From the soil samples collected at Seonginbong in Ulleung Island two unrecorded species of oribatid mite, Punctoribates hexagonus Berlese and Galumna cuneata Aoki were identified. Genus Punctoribates Berlese (1908) are rather small, dark brown, and ball-shaped as adults inhabiting mainly terrestrial ecosystem, but some species live in wet habitats and other mosses at the edge of lakes (Seniczak and Seniczak, 2008). The members of Galumnidae is one of the largest groups of oribatid mites with a world - wide distribution. They are ball-shaped, both the juvenile and adult stages. The sclerotized integument of adults are brown to black. Member of this family are fairly abundant in litter or upper layers of forest soils and commonly distributed in pasture soils of open habitats (Bayartogtokh and Weigmann, 2005). Soil samples were collected from five random samples at 5cm depth consisting of one sample unit. The abundances of soil microarthropods collected from acari and collembola were consisted of 31% and 32%, respectively. We collected 11 species, 9 families of oribatid mite (Acari: Oribatida) from the research site.

The study was conducted to investigate the spring emergence pattern of G. molesta and to forecast the emerging time of overwintering G. molesta on tree fruit orchards. G. molesta is one of major insect pests on fruit trees in Korea. The host range of G. molesta includes many economically important tree fruit plants such as apple, pear, peach and plum. The overwintering G. molesta emerge from late March as an adult lay eggs on the shoot of peach or fruits of apple, plum and peach. Therefore, it is important to understand the biofix and to forecast the emerging peak period of overwintering G. molesta for establishing the pest management strategy. The pheromone trap of G. molesta has been utilized to monitor the population density in apple orchard. The commercial stick trap (GreenAgroTech) and lure (Z8-12:AC, E8-12:Ac, Z8-12:OH, 95:5:1) was set to monitor the population density of G. molesta on each place (56 different fruit orchards). The record of temperature was received from meteorological center close to monitoring orchards. The parameters for forecasting the emerging time and peak period of overwintering G. molesta were calculated from the results of Yang et al (1997 and 2001). Although the estimated biofix of G. molesta was not fitted well, the peak period of overwintering G. molesta was explained by linear regression model. The spring emergence pattern of G. molesta was presented differently related to host plant and geographical location. The peak period of G. molesta at the same mornitoring county was presented differently according to host plant. The synchronization between host plant and G. molesta may be studied to figure out the spring emerging time of overwintering G. molesta.

Gamasid mites are top predators and occupy a central position of the soil food web in the forest ecosystem. This study investigated the soil dwelling gamasid mite community during 8-9 years after the massive mountain fire which occurred in April 2000. Total of 11 families, 44 species and 943 individuals were found. Abundance and species richness of soil gamasid mites was high in less fire-impacted sites (C2 and T3) including unburned control site (Con) than in severely impacted sites (T1 and T2). Genus Holaspina comprised 40-84% of the total abundance of gamasid mites indicating the group may play the key role in soil food web. Dominant species of gamasid mite was H. alstoni, H. communis, H. dentaus, H. ochraceus, H. trifucatus of the Genus Holaspina 5 species in all sites. Some detail biological information was pursued in this group. After 8-9 years from the massive fire, it was noted that the soil gamasid mite communities were recovered from the less severely burned sites but not from the severely burned sites.

Modeling the complex system often provide better understanding of the behavior of the system given that parameters for the modeling are appropriate. The honeybee mite, Varroa destructor Anderson and Trueman, is one of the most serious pests of honeybees in Korea. Even with vast amount of ecological information of this parasite and its host, Apis mellifera, in the world, limited information is available in Korean environment. This paper provides some basic framework of the varroa mite population dynamics modified from published works in western world to adapt to Korean beekeeping environment. Overall population growth rate was in agreement to those previous published. However the detail behavior was quite different mainly because of splitting honeybee colony during the summer season. Although this framework provide reasonable, logical theoretical linkage to varroa mite population growth, implementation of the results provided from this model is not appreciated mainly because this paper is intended to show the basic framework, not the simulated results. Thus, further incorporation of realistic parameters from honey bee and its parasites in Korean environment would provide better insight of the population behavior and management options. Also, research gaps which need to be filled are further discussed.

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.

Identifying effective chemical control agents of Bemisia tabaci biotype B and Q is an important step toward IPM strategy. Until 2008, only 10 chemical agents were registered for B. tabaci. From the laboratory screening of 60 insect- and acaricides, 18 chemicals for egg, 10 for nymph and 8 for adult stage were found effective (>90% mortality). Also ten chemicals were less toxic to B. tabaci. Among ten chemicals, some conventional insecticides need further careful resistance monitoring. Field trials with some of the selected chemicals open the possibility to chemical control of B. tabaci biotype Q. Further consideration of non-target effects and resistance development has to be exerted before registration process.

Environmental tolerance of three important spider mite predators; Neoseiulus womersleyi, Neoseiulus californicus and Phytoseiulus persimilis (Phytoseiidae) was experimented by treating combination of temperature and relative humidity for egg hatching and immature survival. Egg hatching rate increased at the relative humidity incrased for three species. Temperature effects were only significant to N. californicus and P. persimilis. The lethal humidities for three species were in the range of 56-77, 82.0, 66-94% RH, respectively. Larva does not need to feed for larval development into protonymph in three tested species. No larvae survived at lower than 75% RH for N. womersleyi, but around 80% at 95% RH. N. californicus larvae survived around 50% and 100% at 75 and 95% RH. P. persimilis larve survival was decreased as the temperature increased at 75% RH, but platued around 100% at 95% RH. Cannibalism was higher in N. californicus and lower in P. persimilis. Implementation of the results was discussed relative to biological control of spider mites in open field and greenhouse crops.

Community analysis of oribatid mites was conducted in unburned and burned area of Samcheok-si, Gangwon province with differential burn severity that occurred in April 2000. Except control site, four sites (T1, T2, T3 and C2) were selected according to burn severity and subsequent recovery following a year after fire form T1 (heavily burned) to Control (unburned). This study analyzes the abundance, species richness, diversity and evenness, similarity, dominant species, and MGP types of oribatid mites. Oribatid mites were sampled 8times from each site from 2005 to 2007. Total of 40 families, 58 genus, 123 species and 4,638 individuals were founded. Species richness and abundance of oribatid mites decreased as burn severity increased. Diversity index of control site was higher than all other sites and decreased as the burn severity increased. Similarity between control and C2 sites was highest among the sites and cluster analysis showed control and C2 as closely related followed by T3, T2 and T1 respectively. MGP-I analysis revealed oribatid mites of all sites as GP type. MGP-II analysis showed control as G type and all other sites as GP type.

Gamasid mites are free living predators of soil mites, collembolans, nematodes and other small insects in soil surface. We studied the faunal assemblages of gamasid mites in the severely disturbed mountain sites by fire. Total 12 families 55 species were found from this study. From all sites, species in the family of Parholaspidae were dominant; Holaspina alstoni and H. dentatus. Also, Rhodacarus dentitulatus was also abundant regardless of fire disturbance. In control site, Asca aphidioides was also abundant but not in any of the fire disturbed sites. The abundance was highest in control site followed by IC2, IT3 and lower in IT2 and IT1. Species richness was in the same order of abundance ranging from 2.6 to 12.8 per site. In all sites, species diversities were relatively low ranging from 0.6 to 1.7, but it was higher in control site and lower in IT1. Further discussion will be made on the recovery process of soil inhabiting mites.

A phytoseiid mite, Neoseiulus californicus was newly found from Jeju citrus orchards in Korea and it is a polyphagous predator of mite and small insect pests as well as plant pollens. Recently in Korean apple orchards, Tetranychus urticae and Panonychus ulmi are imposing similar pest pressure. Even with ample information of this predator interacting with T. urticae, little is known on the interaction with P. ulmi. We investigated temperature effects on life history parameters of N. californicus when feeding on P. ulmi as prey in the laboratory condition to check the possibility to use this predatory mite in apple mite biological control. So, the development, survivorship and life-table parameters of the predator were studied by given mixed stages of P. ulmi as prey under the range of temperatures (15-34°C), RH 75±10%, and photoperiod 16L:8D to determine the effects of temperature. Temperature had a significant effect on mean development time from hatching to adult emergence and other life-history parameters. The results specified that the developmental time is decreased with increasing temperature between 15 and 30oC. Female development times were shorter at 25, 30 and 34°C (3.83±0.07, 3.37±0.24 and 3.53±0.11d, respectively) and were longest at 15°C (15.61±0.22d). Male developmental times were shorter than females ones at each temperature. The highest adult female life span (70.42±3.06d) and oviposition period (35.83±1.43d) observed at 15oC whereas the shortest at 34oC (13.06±1.03 and 7.3±0.94d, respectively). At 25oC, females laid maximum number of eggs (63.94±2) while minimum (16.59±0.98) was at 34oC. In sex ratio, utmost number of females (0.77±0.01) was counted at 25oC and lowest (0.67±0.01) at 34oC. Survivorship during immature development varied from 78.78 to 93.75% with the lowest value recorded at 20 and 34oC. From life table analysis, the shortest generation time (T=10.7d) resulted at 34oC. The highest net reproductive rate (R0=44.31; expected progeny per female) was found at 25oC. The intrinsic rate of natural increase (rm=0.29) and the finite rate of increase (λ=1.33) per day was estimated highest at 30oC. From this study, we found that N. californicus could successfully develop and oviposit vital eggs. Based on these results, we cautiously expect that N. californicus could be used as a biocontrol agent of spider mites in apple orchards when P. ulmi or T. urticae occurs singly or mutually.

Neoseiulus californicus (McGregor) is a potential biological control agent of spider mites in orchards. The field occurrence of this species was first reported from citrus orchards in Jeju Island and recently this mite started to be sold as a commercial product in Korea. However, the natural occurrence of N. californicus in the Korean mainland is unclear or quite limited. At this time, it is not certain whether N. californicus can overwinter in the Korean mainland or not. This mite is presently planning to be used as a biological control agent against spider mites in apple orchards of the Korean mainland. The main objective of this study was to investigate natural overwintering sites of N. californicus and possible factor increasing winter survival of this species, to develop effective method for collecting overwintering population of N. californicus. For the first objective, we conducted field survey in two citrus orchards of Jeju in early and late February 2008. Samples were collected from various possible overwintering sites: citrus trees, ground covers and windbreaks. Total 259 phytoseiid mites were collected, 94% of the mites were identified as N. californicus and 98% of them were adult females. Most of N. californicus were collected from ground covers, specially the weed species which had rosette leaves: Youngia japonica (L.) DC. and Erigeron spp. This result seemed to suggest that N. californicus try to hide beneath weed leaves near ground surface during winter to get successful survival. Thus, the second experiments were conducted in Andong from December 2007 to early March 2008. N. californicus conditioned in a greenhouse with natural day length was individually put in a small tube, and the tubes were kept under different ground surface conditions: bare, fallen leaves and urethane foam. When water had been added in the tube, the mites on bare ground had died after one month, while 70% of the mites of the other cover treatments were surviving. In these cover treatments, 7-10% of the mites had survived until two months, and eventually all died within three months. This result showed that hiding under cover structure near ground surface may be effective to increase winter survival of N. californicus. Therefore, collecting weeds which have rosette leaves may be an effective method to estimate of the overwintering possibility of N. californicus in the Korean mainland.

Spider mite is the most concerned pest in apple production. This study compared and analyzed the historical changes of two mite pests, Tetranychus urticae koch and Panonychus ulmi (Koch) in 16-30 representative apple orchards in the major apple production area; Gyeongnam, Gyeongbuk, and Jeonbuk province of Korea from 1992 to 2007. Monthly sampling of 100 leaves per orchard provided the basic data of population density of two mite species. Among those orchards, chemical spray history was also analyzed from four orchards, which could be representatives of IPM practitioners. It was found that overall population densities of T. urticae were higher than those of P. ulmi for 16 years. Before 2000, T. urticae was dominant over P. ulmi in most orchards. However since 2000, P. ulmi have occurred more than or as much as T. urticae.. Moreover, although there was large fluctuation of occurrences of two mite species over the years and localities, spider mite pressure appeared to decrease, in general. It seemed to relate the timing of ground cover management with pheromone-based IPM implementation nationwide from late 90s. Panonychus ulmi appeared to rise in April and July in general, fall in August, and go up again in the late season; September-October, while T. urticae appeared to begin to rise in June with July or August peak and sometime with late season second peak in October. Application frequency of acaricide has been dropped from four times in the late 1990s to 2.5 times in the late 2000s.