The detoxification enzymes activities were investigated to Tetranychus urticae Koch using five acaricide-resistant strains. Activities of detoxification enzymes which are glutathione S-transferase (GST), general esterases (α-naphthyl acetate and β-naphthyl acetate), and cytochrome C oxidase were determined to each resistant strain mite. Acequinocyl-resistant strain and bifenazate-resistant strain of T. urticae were showed 2.1 folds and 1.6 folds higher relative activity (RA) level of GST than susceptible strain. Other three resistant strain mites were not significant different to susceptible strain mite. General esterases and cytochrome C oxidase were not significant to all the strain of T. urticae. Acaricidal activities of acequinocylresistant strain and bifenazate-resistant strain of T. urticae showed cross-resistant both acequinocyl and bifenazate. However, other strain mites were showed susceptible acaricidal activities to two acaricides. In this result suggests that resistance of two acaricides (acequinocyl and bifenazate) might be influenced by glutathione S-tansferase activity.

인간의 생태계와 서식환경을 공유하고 있는 정주성 거미류의 경우 제한된 서식지 이동 특성으로 인해, 특정유해환경을 효과적으로 감시할 수 있는 환경 지표생물로서의 활용가치가 매우 높은 생명체로 판단된다. 따라서 본 연구는 석면 섬유에 노출시킨 거미의 서폐 미세구조를 관찰하고, 그 결과를 토대로 유해환경을 모니터링할 수 있는 생물지표로서의 활용 가능성에 대해 논의하였다. 고해상도의 주사전자현미경으로 서폐의 미세구조를 관찰한 결과, 기공 주위에 분지된 수지상의 큐티클지주(spike)는 기낭으로 유입되는 공기를 정화하는 필터구조로 작동하였고, 기낭 내부에 수직돌출된 큐티클 지주는 기낭 공간을 안정적으로 확보하고 호흡 표면적을 극대화하는 구조체임이 확인되었다. 짧은 노출 기간에도 불구하고, 기공 개구부의 전 영역에서 청석면의 미세섬유가 검출되어 석면과 같은 환경 오염원에 대한 효과적인 생물지표로서의 가능성을 거미의 서폐에서 확인하였다. 또한, 기낭으로 유입되어 혈림프 공간을 관통한 미세섬유는 고착구조를 형성하고 조직손상을 유발함이 관찰되었는데, 섬유 주위에 밀집된 혈구는 흔히 관찰되었으나, 섬유 표면에 부착된 혈구나 석면소체 등은 관찰되지 않았다. 이는 상대적으로 짧은 석면노출기간에서 기인하는 것으로 해석되었다.

Emergence of resistant two-spotted spider mite (TSSM) can induce the over usage of standard amount of acaricides and result in various side effects. Rapid resistance monitoring is essential step for the efficient management of resistant populations by enabling the selection of appropriate acaricides. Here, we evaluated the 19 acaricides to determine its suitability for residual contact vial bioassay (RCV) by using PyriF strain as a reference. Twelve acaricides (Amitraz Abamectin, Bifenthrin, Bifenazate, Chlorfenapyr, Cyenopyrafen, Cyflumetofen, Endosulfan, Fenothiocarb, Monocrotophos, Omethoate and Tebufenpyrad) revealed the dose-dependent mortality within 8 h, whereas other remaining acaricides (Dicofol, Etoxazole, Fenbutatin oxide, Fenpyroxymate, Flufenoxuron, Spiromesifen and Pyridaben) did not. This finding suggests that the application of RCV method is limited depending on the mode of action and physicochemical properties of each acaricide. Resistance levels to 12 acaricides were determined for four field populations of TSSM by using RCV diagnostic kit. All TSSM populations showed the highest sensitivity to cyflumetofen, indicating that it would be most effective in controling field populations. RCV diagnostic kit would enable to provide crucial information for choosing the most appropriate acaricides in the field.

Sperm cell development in spider species undergoes in testicular cyst, containing certain number of cells per cyst. As a germ cell matures through entire stages of spermatogenesis, testicular cysts rupture and produced spermatozoa are transferred in a form of cleistosperm. When mature spermatozoa pass through deferent duct, it is known that various types of seminal secretions are released into the lumen to provide auxillary functions to the mature sperms – such as nutrition, protection, or sperm release inside the female body. However, a peculiar type of seminal secretion was observed in this study. In the lumen of deferent duct, encapsulated seminal secretions are observed along with coiled sperm cells. Since the capsule is quite thick – as thick as the one of mature sperm cell, it is thought that the secretion capsule would be transferred as well along with the sperm cells into the spermathecae probably activiating sperm cells through decapsulation. Also, this study revealed that sperm storage in deferent duct occurs in droplet-by-droplet basis; which suggests possible sperm inducing mechanism. Since spider uses pedipalps in copulation to transfer its sperm cells, spider has to fill it accordingly. In other words, stored sperms in deferent duct are released in a droplet at once.

Spider community was surveyed at Nakdonggang River which is the longest river (525 km and 23,384 km2) located East-south part of Korea. Nakdonggang river is developing for water management and environmental conservation including restoration of river ecosystem under “The Four-River Restoration Project”. Sampling was made 3 occasions from June to August in 2009. Eight survey sites were selected from both sides of river in Andong, Sangju, Gumi and Seongju prefectures. Spiders were collected with sweep net for on the plants above ground and pitfall traps for on the ground. A total of 94 species of 71 genera in 24 families were identified from 805 collected spiders. Species richness was high in Salticidae (18 species, 19.1%), Araneidae (12 species, 12.8%), Lycosidae (9 species, 9.6%) in order. Wandering spiders (55 species occupied 58.5%, 493 individuals occupied 61.2%) were higher than webbing spiders (39 species occupied 41.5%, 493 individuals occupied 61.2%) in species richness and abundance. Dominant species were Tetragnatha praedonia (Tetragnathidae) and Neoscona adianta (Araneidae) in webbing spiders, and Anahita fauna (Ctenidae), Pirata procurvus (Lycosidae) and Gnaphosa kompirensis (Gnaphosidae) in wandering spiders with abundance. Collectively, most spiders collected from this study were water preferring spiders and showed different community structure compared to other reports from terrestrial spider fauna. Present result will bevaluable to compare the effect of development on the arthropod fauna after completion of the project.

Post-maternal social organisation of Amaurobius ferox (Araneae, Amaurobiidae) provides an opportunity to investigate the mechanisms of social behaviour in spiderlings while controlling for potential effects of maternal presence. Development and characteristics of locomotory behaviours in young individuals of the subsocial Amaurobius ferox were examined. Young collectively show a very rapid and linear locomotion in a short distance in response to an intruder in the natal nest. Such a locomotory behaviour of the spiderlings resembles the successive synchronised stepping towards prey of the permanently social spider, Anelosimus eximius. We observed the development of different types of locomotion relative to the age of young, collective tendency (i.e., proportion of individuals within the clutch engaging in the behaviour), and directional properties of the locomotion. Locomotory behaviours of spiderlings fell into two categories: ‘abrupt locomotion’ (AL), involving fast and linear movement over a short distance; and ‘ordinary locomotion’ (OL), involving slower movement over longer distances and times. The frequency of AL (abrupt locomotion) did not vary much throughout the days post-matriphagy, occurring for a limited period of time. On the other hand, the frequency of OL (ordinary locomotion) varied over the days post-matriphagy and increased during the maternal social period.

For replacement of methyl bromide(MB) in Korea, VapormateTM, a gas formulation of ethyl formate(EF) with carbon dioxide, are firslty introduced in import bananas and VivakilTM, a gas formulation of phosphine(PH3) with carbon dioxide, are ready to commercial use in export cut flowers. Their applications are being extended for other import and export commodities. Ethyl formate have been shown to have effectiveness short exposure time(<4hr) but it has a limited application at low temperature for TSM(Two spotted spider mites) due to some phytotoxic to strawberry. Phosphine gas has demonstrated their efficacy to TSM at low temperature but only meets quarantine requirement when applying longer fumigation time(>24hr) to control CA(cotton aphids). We firstly evaluated two MB alternatives, EF and PH3, have enhansive effect within short exposure time(4hr) at low temperature(5℃) for controlling both TSM and CA without any injury to export strawberries.

Emergence of resistant two-spotted spider mite (TSSM) can induce the over usage of standard amount of acaricides and result in various side effects. Rapid resistance monitoring is essential step for the efficient management of resistant populations by enabling the selection of appropriate acaricides. Here, we evaluated the 10 acaricides to determine its suitability on residual contact vial bioassay (RCV) by using PyriF strain as standard. Five acaricides (Abamectin, monocrotophos, tebufenpyrad, bifenazate and cyflumetofen) revealed the dose-dependent mortality within 8 h, whereas other remaining acaricides (Fenbutatin oxide, fenpyroxymate, flufenoxuron, spiromesifen and etoxazole) did not. This finding suggests that the application of RCV method is limited depending on the mode of action and physicochemical properties of each acaricide. Resistance levels to five acaricides (Abamectin, monocrotophos, tebufenpyrad, bifenazate and cyflumetofen) were determined for four field populations of TSSM by using RCV diagnostic kit. All TSSM populations showed the highest sensitivity to cyflumetofen, indicating that it would be most effective in controling field populations. RCV diagnostic kit would enable to provide crucial information for choosing the most appropriate acaricides in the field.

 ,  , The hawthorn spider mite, Tetranychus viennensis, is a pest of apples and a quarantine pest from some countries that import apples from Korea. A controlled atmosphere and temperature treatment system (CATTS) was developed as an alternative disinfestation method to methyl bromide fumigation treatment, and has been applied to control various insects and other arthropod pests on fruits. We applied CATTS to disinfect T. viennensis under conditions that were previously developed to control the peach fruit moth, Carposina sasakii. First, T. viennensis was sampled from Japanese apricot, Prunus mume, and identified by its morphological characters. In addition, both cytochrome oxidase I (COI) and internal transcribed spacer (ITS) sequences supported the morphological identification. Second, the heat-tolerant developmental stage was determined in T. viennensis. When a 46℃ heat treatment was applied to egg, nymph, and adult stages of T. viennensis, adults were the most tolerant stage. Third, when heat temperature was used along with 1% O<, SUB>, 2<, /SUB>, and 15% CO<, SUB>, 2<, /SUB>, , the mites showed a significant increase in susceptibility to the heat treatment. Finally, CATTS at 46℃ with 15% CO<, SUB>, 2<, /SUB>, and 1% O<, SUB>, 2<, /SUB>, for 30 min resulted in 100% mortality of all T. viennensis development stages. These results indicated that CATTS isapplicable to disinfest T. viennensis in post-harvest apples.

Spider silks hold great potential as biomaterials with extraordinary properties. Here we report cloning and characterization of the major ampullate silk protein gene from the spider Araneus ventricosus. A cDNA coding for the partial major ampullate silk protein (AvMaSp) was cloned from A. ventricosus. Analysis of the cDNA sequence shows that AvMaSp consists of 240 amino acids of a repetitive region and 99 amino acids of a C-terminal non-repetitive domain. The peptide motifs found in spider major ampullate silk proteins, (A)n, (GA)n, and (GGX)n, were conserved in the repetitive region of AvMaSp. Phylogenetic analysis further confirmed that AvMaSp belongs to the spider major ampullate spidroin proteins. The AvMaSp-R cDNA, which contains sequences encoding for 240 amino acids of a repetitive domain, was expressed as a 22 kDa polypeptide of soluble form in baculovirus-infected insect cells. Recombinant AvMaSp-R was degraded abruptly by trypsin. However, AvMaSp-R was stable at 100 °C for at least 30 min. Additionally, the AvMaSp-R was stable at various pH values from 2 to 12 for at least 1 h. Taken together, our findings provide the molecular structure and biochemical property for A. ventricosus major ampullate silk protein as a biomaterial.

The two-spotted spider mite Tetranychus urticae is a worldwide crop pest with a high insecticide resistance and an extensive host range. The aim of the present study was to evaluate the effect of PaeciPora®, which was formulated from the aerial conidia of an entomopathogenic fungus Paecilomyces lilacinus strain HY-4, to control T. urticae in cucumber field. In the field study, conidia of P. lilacinus HY-4 and a chemical acaricide azocyclotin were investigated for their control of the adult females of T. urticae. The strain produced a mortality of 56.0% on day 3 and 63.6% on day 7 post-treatment respectively at 1×107 conidia/mL, and no evidence of a mortality benefit was seen in the control group. Additionally, in the pesticide injury test, no agrochemical damage was found in hot pepper, watermelon, Chinese cabbage, oriental melon or strawberry by spraying PaeciPora® on them. The results indicated the possibility of the use of P. lilacinus HY-4 as a microbiological control agent against T. urticae in the Integrated Pest Management program.

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is one of the most important pest species devastating many horticultural, ornamental crops and fruit trees. Difficulty in managing this mite is largely attributed to its ability to develop resistance to many acaricides. Development of 3,700 folds resistance to etoxazole was found in the population of T. urticae collected from rose greenhouses in Buyeo, Chungnam Province in August 2000. This population has been selected for eleven years with etoxazole (over 500 times), and increased over 5,000,000 fold in resistance as compared with susceptible strain (S). Etoxazole-resistant strain was shown to be maternally inherited. The objective of this study was to determine whether resistance of T. urticae to etoxazole was linked with point mutations in the mitochondrial gene. DNA sequencing of cytochrome c oxidase subunit I (COX1), COX2, COX3, cytochrome b (CYTB), NADH dehydrogenase subunit 1 (ND1), ND2, ND3, ND4, ND5, and ND6 were analyzed by comparing two isogenic etoxazole-susceptible (EtoS) and etoxazole-resistant (EtoR) strains. As a result, all genes revealed no point mutations between the two strains.

Five erigonine spider species are described with illustrations: a new species, Saitonia pilosus n. sp., and four records new to the Korean spider fauna, Ceratinella brevis (Wider, 1834), Erigone atra Blackwall, 1833, Maso sundevalli (Westring, 1851), and Parasisis amurensis Eskov, 1984. The occurrences of four spider genera, Ceratinella Emerton, 1882, Maso Simon, 1884, Parasisis Eskov, 1984, and Saitonia Eskov, 1992, are also new to Korea.

Many animals are capable of detecting sensory information emitted by predators. When predation risk is high, orb-web building spiders should change its foraging strategy of the web construction. We examined web building behaviors of an orb-web spider, Argiope bruennichi providing sensory information of its predator, a yellow hornet, Vespa simillima. We observed web characteristics after providing sensory information of the yellow hornet (experimental group; N=29) and compared to the control group (no information provided; N=34). We hypothesized that the spiders in the experimental group would decrease investments in its web construction and stabilimentum decoration to avoid being located by the predator. The results rejected our hypothesis. Web and stabilimentum constructions decreased in the course of the experiment in both control group and experimental group. But the differences between control group and experimental group were not significant. The individuals did not reduce its stabilimentum length and did not decrease its web area in spite of sensory information of the predator.

Two-spotted spider mite, Tetranychus urticae (Koch) is one of the serious pests in economically important crops such as strawberry and cucumber and so on. Acaricides have been used as the main control agents. This study was conducted to test the synergistic effects of the Beauveria bassiana GHA, which has been registered for whitefly and thrips, and five pesticides (abamectin, acrinathrin, bifenthrin imidacloprid, dinotefuran, and indoxacarb, which are commonly used pesticides in strawberry in Korea), on the two-spotted spider mite T. urticae. Five tested pesticides did not inhibit spore germination and mycelial growth of B. bassiana. Pesticides were applied to potted strawberry plants at four different treatments (recommended concentration, 1/5 recommended concentration, 1/5 recommended concentration + GHA(108 conidia/ml), and only GHA(108 conidia/ml). Mortality in larvae of two-spotted spider mite was 12% in GHA 5 day after treatment. Mortality in abamectin treated T. urticae was 98.5% and 100% at 1/5 recommended concentration and recommended concentration, respectively, 3 days after treatment. Acrinathrin, indoxacarbe, dinotefuran and difenthrin imidacloprid caused 60%, 14%, 16% and 91% mortality at recommended concentration 5 day after treatment. The tested five pesticides and B. bassiana GHA had no synergistic effect.

The two-spotted spider mite, Tetranychus urticae Koch, is an economically important pest of crops of plant grown in the field or greenhouse worldwide. It has recently become a serious problem because of the continuous use of acaricides resulting in resistance among spider mite population. Thus, there is a need to find alternative control measures to suppress spider mite populations. In this study, we report the screening result of pathogenic fungi for the control of spider mite. Initial screenings were performed using 352 isolates of putative pathogenic fungi from Korea soils. As results, 11 strains of acaropathogenic fungi were isolated from 8 cadavers of spider mite supporting fungal conidiation. These isolated were identified as four isolates of Beauveria bassiana (6, 2R-3-3-1, 2R-4-5, 2R-4-7), two isolates of Metarhizium anisopliae (4-2, 2-2), one isolate of Clonostachys rosea 5-2, one isolate of Lecanicillium attenuatum 4-1, one isolate of Pochonia suchlasporia 2R-3-1, one isolate of Aspergillus flavus 7 and one isolate of Isaria lilacinus 2R-4-6 by microscopic examination and genetic sequencing of the ITS region. Based on the screening results, eleven isolates were tested for their virulence against adult spider mites. All fungal isolates were pathogenic to spider mite but mortality varied with isolates. These acaropathogenic fungi may be useful to develop eco-friendly acaricide to control two-spotted spider mite.

Western blot analysis using acetylcholinesterase (AChE)-specific antibody was conducted to determine whether AChE gene (Tuace) duplication actually results in overproduction of AChE in Tetranychus urticae (TuAChE). The protein quantities of TuAChE in seven field-collected mite populations were precisely correlated with the copy numbers. To investigate the effects of each mutation on AChE insensitivity and possible fitness cost, eight variants of TuAChE were in vitro expressed using the baculovirus expression system. Kinetic analysis revealed that the Ala391Thr mutation did not change kinetic properties of AChE, whereas the Gly228Ser and Phe439Trp mutations significantly increased the insensitivity to monocrotophos. Moreover, when the Gly228Ser and Phe439Trp mutations are present together, insensitivity increased over a thousand-fold, showing that both mutations confer resistance in a synergistic manner. Presence of the mutations, however, reduced catalytic efficiency of AChE considerably, suggesting an apparent fitness cost in monocrotophosresistant mites. Reconstitution of the multiple copies of AChE having different compositions of mutations revealed that the catalytic efficiencies of the six-copy and two-copy AChEs (resembling the AD and PyriF strains of mite, respectively) were still lower but comparable to that of wildtype AChE. These finding clearly suggested that multiple rounds of Tuace duplication was needed to compensate the reduced catalytic activity of AChE caused by mutations.

Vapormate™, a new gas formulation of ethyl formate (EF) with carbon dioxide, is an alternative fumigant to methyl bromide (MB). The efficacy of the vapormate fumigation was evaluated on an acaricide susceptible and resistant Tetranychus urticae strains. A resistant strain showed resistance ratio (RR) of 21.9 and 379.6 to acrinathrin and chlorfenapyr, respectively. Fumigation was done in desiccators (6.8 L) which were empty or filled 30% in space with paprika for 6 h at 15℃ in the laboratory. The concentration adopted were 9.6, 17.2, 24.5, 36.4 mg/L in empty desiccator and 10.2, 17.9, 24.9, 35.2 mg/L in paprika-filled desiccator. In empty desiccator, susceptible and resistance T. urticae showed 100% mortality at higher concentration than 17.2 and 24.5 mg/L, respectively. In paprika-filled desiccator, susceptible and resistance T. urticae showed 100% mortality at higher concentration than 24.9 and 35.2 mg/L, respectively. Hatchability was greatly reduced by the fumigation. Hatchability was 3.7% in the empty desiccator at 9.6 mg/L and 37.2% in the paprika-filled desiccator at 10.2 mg/L.

The two-spotted spider mite, Tetranychus urticae Koch is the most harmful pest among many cropping systems, particularly vegetables and other annual crops. In this study, the methanol extract from the inner bark of Tabebuia impetiginosa was evaluated for acaricidal activity against T. urticae by using a leaf disk method and were compared with commercial acaricide, abamectin. A crude methanol extract of T. impetiginosa had strongly acaricidal activity at 2,000 ppm against the T. urticae. Methanol extract of T. impetiginosa was partitioned with hexane, chloroform, ethyl acetate, butanol and water fraction, successively. In this result, the chloroform fraction showed a strong acaricidal activity at 1,000 ppm. Therefore, active fraction of T. impetiginosa extract was purified by using silica gel column chromatography and high performance liquid chromatography. The structure of acaricidal component was analyzed by EI-MS, 1H-NMR and 13C-NMR spectra, and was identified as TI-3123. Based on the LC50 values of TI-3123 and abamectin against T. urticae were resulted in 0.011 mg/l and 0.340 mg/l, respectively. These results showed that acaricidal activity of the T. impetiginosa can be mostly attributed to TI-3123. Furthermore, TI-3123 was approximately 30.91 times more toxic than abamectin against T. urticae. All these results suggested that active component in T. impetiginosa derived materials could be use for biological control for T. urticae. Further studies should be performed to the structure activity relationship of TI-3123 and compared with its derivatives.

Spider mites are one of major pests in cultivations of various ornamental plants and also important in plant quarantine service. Due to the very small body size and high similarity within the Genus the identification of species is difficult even at the microscopic observation. To identify 5 major species (Tetranychus cinnabarinus, T. urticae, T. phaselus, T. kanzawai and T. truncatus) in the Genus Tetranychus at the molecular level, we designed 4 species-specific primer sets using nucleotide sequences of the internal transcribed spacer (ITS2) region in the nuclear ribosomal repeat unit. At the PCR diagnosis of extracted genomic DNAs of 5 species using each primer set, specific primers of both T. phaselus and T. truncates were species-specific to their own species samples. However, specific primer set of T. urticae detected T. cinnabarinus as well as T. urticae. Specific primer set of T. kanzawai detected T. truncates as well as T. kanzawai, even though detection intensities were lower in non-target species.