• Korean journal of applied entomology
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• v.12 no.3
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• pp.125-130
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• 1973

To study the faunal compositiion of spiders as natural enemies of the insect pests and their seasonal fluctuation in paddy fields of Taegu, the survey was carried out 12 times between June and September. 1971. 1. The spiders collected in paddy field of Taegu during the survey period were 45 species of 30 genera of 10 families. 2. In percentage composition the spiders of the genus Pirata were most abundant. Among the other genera, the species of the genus Neoscona, Lycosa, and Marpisa were more abundant in the above-written order. 3. Pirata subpiraticus, Neoscona doenitzi, Lycosa sp., Pardosa T-insignita and Marpisa magister were the 5 major species of abundant spiders. 4. Comparing the spider-fauna of the paddy field of Korea with that of Japan, Taiwan and Thailand, 2 species of 2 genera of the family Gnaphosidae were found in Korea only The abundant and common species It·ere deeply different each other. 5. Pirata subpiraticus, Lycosa sp. and Pardosa T-insignita appeared abundantly between June and July while Neoscona doenitzi and Marpisa magister were few in these periods. But no Pirata subpiraticus, Lycosa sp. and Pardosa T-insignita appeared in August while Neoscona doenitzi and Marpisa magister were abundant in this period. Then, in September as between June and July, Pirata subpiraticus, Lycosa sp. and Pardosa Tinsignita were abundant while Neoscona doenitzi and Marpisa magister decreased.

• Korean journal of applied entomology
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• v.23 no.3 s.60
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• pp.166-171
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• 1984

The present studies were conducted to investigate the relative toxicity of several insecticides to the rice insect pests and the predatious spider, Pirate subpiraticus. In laboratory test by topical application, BPMC and MIPC for the plant and leafhoppers were toxic to Nilaparvata lugens, but less toxic to Pirata subpiraticus. Other carbamate insecticides such as carbaryl, carbofuran, and MTMC showed highly toxic effect on P. subpiraticus as well as N. lugens. No organophosphates showed selective toxicity to P. subpiraticus. Thiocyclam, effective to Chilo suppressalis and Sesamia inferens, had highly good selective toxicity to P. subpiraticus. In case of insecticides for Nephotettix cincticeps, BPMC only had a little selective toxicity between N. cincticeps and P. subpiraticus. Organophosphate insecticides which had been reported to induce chemical resistance to N. cincticeps showed high $LD_{50}$ value to N. cincticeps. In pot trials, dust formulation was more toxic to P. subpiraticus than emulsifiable concentrate. It was more toxic to P. subpiraticus to increase number. of insecticide application.

• Korean journal of applied entomology
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• v.18 no.4 s.41
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• pp.149-152
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• 1979

The relative toxicity of some of the insecticides which have been used for the control of paddy rice insect pests in Korea was evaluated in the laboratory with the brown planthopper (BPH) Nilaparvata lugens, and a predaceous paddy spider Pirata subpiraticus. In order of the relative toxicity (LD5O value to spider/LD50 value to BPH) were PAP (0.4), MPP(0.1), MEP(1.8), diazinon(2.8), carbofuran(7.5), NAC(11.3), BPMC(17.5), Pyridaphenthion(35.9) and MIPC(65.7). MIPC and Pyridaphenthion were considered as having the desirable selective toxicity for the spider and the BPH.

• Korean Journal of Environmental Agriculture
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• v.13 no.1
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• pp.98-110
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• 1994

The fauna of spider species inhabited near paddy fields have been investigated in Chinju and Namhae areas. The spiders collected near the paddy fields in Chinju and Namhae areas were 34 species of 31 genera belonging to 10 families: 34 species on paddy levees; 16 species on barley fields; 17 species on fallow fields; and 18 species on paddy fields. The species diversity was the highest on paddy levee. The dominant species collected from each habitat near the paddy fields were Pardosa astrigera on the paddy levees and barley fields, Pirata subpiraticus on the fallow field, and Pachygnatha clercki on the paddy fields. The spiders inhabited near rice fields can be classified into nine groups based on the ecological and taxonomical characteristics: 1. Pirata spp. 2. Pachygnatha clercki 3. Teridiidae, Erigonidae, Linypidae 4. Tetragnatha spp. 5. Dolomedes surfureus 6. Pardosa spp. 7. Salticidae 8. Thomisidae 9. Clubionidae Among the nine spider groups, the spiders belong to the group 1-5 prefered wet ground or paddy to dry ground, in contrast to the group 6-9 which prefered to live on dry land. The difference of the habitat preference indicated that the former five groups do the important roll as pest predators in paddy, while the latter four group mainly suppress the overwintering pest populations on paddy levees.

• Korean journal of applied entomology
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• v.56 no.4
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• pp.331-338
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• 2017

In the present study, we investigated the effects of two herbicide-resistant genetically modified rice (GM rice) varieties, Milyang 204 and Iksan 483, recently developed in Korea on non-target insects and a spider. No difference in host preferences of the English grain aphid Sitobion avenae and the brown planthopper Nilaparvata lugens were observed between GM rice and non-GM rice. Wolf spider Pirata subpiraticus, feeding on N. lugens reared on GM rice or non-GM rice, revealed no significant difference in body weight. P. subpiraticus, fed with N. lugens reared on Milyang 204, showed survival rates similar to that in P. subpiraticus fed with N. lugens reared on non-GM rice. However, P. subpiraticus feeding on N. lugens reared on Iksan 483 demonstrated significantly lower survival rates than that in P. subpiraticus feeding on N. lugens reared on Milyang 204 or non-GM rice. In addition, when larvae of the western honeybee Apis mellifera were supplied with Iksan 483 pollen, a significantly longer pupal period occurred, as compared with that of A. mellifera supplied with pollen of Milyang 204 or non-GM rice. As GM rice has negative effects on P. subpiraticus, which is an important predator in agricultural ecosystems, and on A. mellifera, which plays important roles in pollination and honey production, additional studies on risk assessment of GM rice should be conducted before releasing newly developed herbicide-resistant GM rice to the agricultural environment.

• Korean journal of applied entomology
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• v.36 no.1
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• pp.55-66
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• 1997

This study was conducted to analyze arthropod community patterns in small rice fields associated with different planting methods (water seeding, drill seeding, and hansplanting) in Suwon and Icheon in 1994. Total 15 orders and 45 families of arthropods were collected. The arthropod community was analyzed using guild categories. The arthropods were found in the order of 'natural enemy>pest(phytophage)>non-pest' in their densities in all sites. The pest (phytophage) species were mainly Homoptera and dominated by Delphacidae (Nilaparvata lugens Stsl, Sogatella fircifera Horvath and Laodelphax striatellus Fallen) and Cicadelidae (Nephotettir cincticeps Uhler). They constituted >80% of pest abundance. Differences in pest abundance were not found among rice fields associated with different planting methods. Spiders were the most dominant group in the natural enemy and constituted >90% of natural enemy abundance. Hunting spiders constituted >SO% of spider abundance and were dominated by Pirata subpiraticus Bos. et Str. (Lycosidae). Pacliygnatha clerki Sundevall (Tetragnathidae) was a dominant species in webbing spiders. No differences were found in species richness and diversity in spider community among rice fields associated with different planting methods. The nonpest species were mainly Diptera and occurred abundantly in early growing season and decreased drastically as rice development proceeded. The non-pest abundance was higher in direct seeding sites than in transplanting site, and especially abundant in a drill seeding site.

• The Korean Journal of Ecology
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• v.28 no.5
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• pp.287-293
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• 2005

This study was conducted to evaluate the effect of the conventional pesticide application system on the rice spider community based on the quantitative investigation of arthropod community in the rice fields in Saran area, Hwasung-si, Kyeonggi-do from 1996 to 1998. Spiders were the highest dominant group comprising over 90% of all natural enemies in their density, and showed very stable yearly occurrence. In these fiekds the mean density of spiders was about 10 individuals/$0.25m^2$ during the rice growing season, and three families including Lycosidae, Tetragnathidae and Linyphiidae were very abundant. The colonization of spiders occurred in early season and they showed rapid density increase in mid-season. They maintained the highest density to the late season and their density decreased at harvest season. In the years of the low rice pest occurrence, the disturbance effect on spider community by pesticides were less. Two dominant species, Pirata subpiraticus and Pachygnatha clerki, had different population dynamics; Pirata subpiraticus showed the rapid density increase in the mid-July, and most of them remained immature stages, however, in the case of Pachygnaths clerki population, they rapidly increased in the late August and most of them remained adult stage during the late growing season.

• The Korean Journal of Ecology
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• v.21 no.1
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• pp.15-26
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• 1998

This study was conducted to analyze arthropod community patterns in smallrice fields managed by different cultural methods [Conventional and Low Input Sustainable Agriculture(LISA)] in Suwon in 1995 and 1996. A half of nitrogen fertilizers and a quarter of pesticides were applied in the LISA field compared to in the conventional field. Total 15 orders and 43 families of arthropods were collected in two years. No differences were found in arthropod abundance and arthropod species composition between two differently practiced fields. The arthropod community was analyzed using guild categories. The arthropods were found in the order of 'pest(phytophag)>natural enemy>non-pest' in their densities. The pest species were mainly Homoptera and dominated by Delphacidae (Nilaparvata lugens Stal and Sogatella furcifera Horvath). They constituted > 80% of pest abundance. The spider was the most dominant group in the natural enemy and constituted > 90% of natural enemy abundance. Hunting spiders constituted > 60% of spider abundance and were dominated by Pirata subpiraticus Bos. et Str.(Lycosidae). Pachygnatha clerki Sundevall(Tetragnathidae), Gnathonarium dentatum Weider and Ummeliata angulituberis Oi(Erigonidae) were the dominant species in webbing spiders.

• Korean Journal of Agricultural Science
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• v.8 no.1
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• pp.18-28
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• 1981

The purpose of this study was to establish the intergrated control of rice insect pests. Specific objectives were to reveal the diversity of natural enemies in rice field environment, to obtain basic informations of their population dynamics, and to screen the selective insecticides for the conservation of natural enemies. The results of the study were as follows. 1. In numbers of species and in numbers of each species of parasitic Hymenoptera of rice insect pests were more diverse and abundant in rice paddy leeves and banks than paddy fields. Braconid Mymarid and pteromalid were predominated in the field and their population was high during early August to mid September. 2. Of the predatory spiders, Pirata subpiraticus was the largest in number and amounted to 72% of the total, Gnatonarium dentatum, Pachygnatha clerki and Clubiona japonicola were the next. It was also found that P. subpiraticus had three generations in a year. 3. Hence the activities of the predatory spider species and parasitic Hymenoptera were high in early to mid August and September, it would be better promising to avoid chemical applications at this time of periods as possible. 4. The relative toxicity of several insecticides which have been used for the control of brown plant hopper (BPH) showed that P. subpiraticus was 1.1-73.1 times higher than BPH and G. dentatum to P. subpiraticus was 1.1-73.1 times, respectively. 5. Three conventional insecticides, Padan, Diazinon and Carbofuran were screened for toxicity to predatory spider species. The insecticides deffered in their toxicity to the predators. However, Padan was appeared to be the least toxic to the predators.

• Korean journal of applied entomology
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• v.29 no.3
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• pp.209-215
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• 1990

Some preliminary studies were conducted to find out whether the levee-burning could justifiable for the suppression of insect pests, particularly the smaller brown planthopper (Laodelphax striatellus F.). Density surveys on pests and their enemies (mostly spiders) were carried out upto the mid May at an experimental paddy field located in Suwon after of it's levee $(72\times1m)$ was burned on Feb. 20, 1987. Results were discussed in relation to density recovering of both pests and their possible enemies (spiders) and summarized as below. Not a single individual of any pest or enemy was found from the levee upto sometime after the levee-burning. Grasses started to grow more vigorously in burned ares than in unburned upto about 60 days after the burning. And densities of both pest and enemies grew higher in burned areas than in unburned from about 75 days after the burning (in Early may). It is suspected that all individuals of pests and enemies fond from the burned areas could have immigrated from the surrounding areas. If levee-burning was carried out in much wider areas, much longer time would be needed to recover the density of both pests and enemies to the center region of the burning. Wingless spiders would require even longer time than winged pest species to re-establish in the center region of the widely burned field. Pirata subpiraticus, the most abundant spider species in Korean paddy fields, starts to move about and searches for food at above $9^{\circ}C$ which is somewhat lower than the critical temperature for the pest species. Thus P. subpiraticus would require more food than other pest species early in the spring, and therefore, it would have lower probability to survive than pest species particularly in burned areas. Experiments for pest suppression with levee-burning would better be carried on in much wider areas, and its justification seems to be discussed after man other disciplines related to both pests and their natural enemies were throughly studied together with their density surveys. However, according to the present point of vie, the opinion that levee-burning is helpful for controlling pests which over winter on levee areas could not be justifiable.