Myung-Pyo Jung

Accumulated Heavy Metal Content in Wolf Spider, Pardosa astrigera (Araneae: Lycosidae), as a Bioindicator of Exposure

Abstract To investigate the rate and extent of heavy metal accumulation in a potential indicator species of wolf spider, Pardosa astrigera (L. Koch) (Araneae: Lycosidae), adult spiders were exposed to three different heavy metals by dietary uptake. The spiders were regularly fed with heavy metal-coated fruit flies (20 mM CdCl 2 , 10 mM PbCl 2 , 10 mM HgCl 2 ; singly or altogether) up to 8 weeks, and the heavy metal contents in individual spiders were analyzed. Accumulation pattern of individual heavy metal in P. astrigera body was significantly different. Both Pb and Hg reached the accumulation saturation point (ca. 3-4 ug/spider) in a relatively short period of exposure (two weeks). In contrast, the Cd accumulation gradually increased up to 6 weeks and then arrived at the saturation point (ca. 10 μg/spider). These findings indicate that the spider is more selective in the Cd accumulation compared to Pb and Hg. Similar patterns of individual heavy metal accumulation were also observed in the exposure to complex heavy metals, where the accumulation capacity for Cd was most significant. The contents of Cd and Pb in the P. astrigera collected from the down-stream area of Sin-gil stream were ca. 1.2 and 1.6 μg/spider, lower than the saturation level, but well reflecting the heavy metal contamination status of the area. The Cd accumulation in P. astrigera was also confirmed by histo-chemical staining of Cd with QAI [2-(8-quinolylazo)-4, 5-diphenylimidazol], in which vacuole-like complexes containing Cd were intensely stained in the hepatopancreatic tissue of the 20 mM CdCl 2 -exposed spider. No mortality was observed during the time course of heavy metal exposure but the development of P. astrigera both in nymphal and sub-adult stages was suppressed by the constant exposure to 20 mM CdCl 2 as judged by the reduced rate of body weight gain, suggestive of its apparent sub-lethal effects.

Assessing environmental impacts of reclaimed wastewater irrigation in paddy fields using bioindicator

Irrigation water quality influences many aspects of agroecosystems, but less is known about how complex microbial and biological communities respond to changing water quality due to causes such as reuse irrigation. The objectives of this study are to monitor and assess the environmental impacts of reclaimed wastewater irrigation on water quality and soil that might cause potential health hazards and to assess its agro-environmental effects. Two sites, which are irrigated by filtered wastewater after UV (Ultraviolet) treatment and from an agricultural reservoir that satisfied the agricultural water quality standards of Korea, were selected as treatment and control, respectively. The environmental impacts of irrigation water quality on paddy soil, microorganisms, and arthropods were investigated. Monitoring results for water, soil, health risks, and eco-environments of the reclaimed wastewater irrigation site demonstrated no adverse effects in the paddy field. This research showed that reclaimed wastewater irrigation did not present significant environmental risks for the rice paddy agroecosystem, although long-term monitoring is needed to fully characterize its effects.

Bioaccumulation of heavy metals in the wolf spider, Pardosa astrigera L. Koch (Araneae: Lycosidae)

Previous studies have proposed that Pardosa astrigera L. Koch (Lycosidae) can be used as a biological indicator of heavy metal contamination in soil. In this study, we estimated the bioaccumulation levels and the bioconcentration factors (BCF) of four heavy metals (Cd, Cu, Pb, and Zn) in adult female P. astrigera collected from various field sites according to heavy metal content gradient and broods. The relationship between heavy metal content in the soil and that in spiders was different depending on the heavy metals and the broods. However, heavy metal content in P. astrigera increased with increasing heavy metal content in the soil. While the heavy metal content in the soil was in the order of Zn > Pb > Cu > Cd, its content in P. astrigera was in the order Zn > Cu > Cd > Pb. The BCF for Cd in both of the broods was distinctly higher than those of the other heavy metals evaluated. These results indicate that P. astrigera may be useful as a biological indicator of Cd soil contamination.

Spatio-temporal dynamics of Scotinophara lurida (Hemiptera: Pentatomidae) in rice fields

Studying the spatial pattern of insect pests and the temporal stability of their patterns is important in understanding underlying ecological mechanisms and in developing pest management programs in cultivated crop systems. To elucidate the spatio-temporal pattern of the black rice bug, Scotinophara lurida, in rice fields, samplings were conducted in two rice fields over 2xa0years. Using spatial analysis by distance indices, the spatial pattern of each developmental stage of S. lurida and their temporal stability of the spatial pattern were identified. Most of the Ia (the index of aggregation) values for overwintered adults and eggs of S. lurda were close to 1, indicating random distribution pattern while nymphs and new adults mainly had Ia values >1, indicating an aggregated distribution pattern. According to spatial association analysis between successive samples using X (the index of spatial association), the spatial pattern of S. lurida showed strong temporal stability throughout the season. Also, there was strong association between the spatial patterns of developmental stages, indicating the great effect of the spatial pattern of the previous developmental stage on that of later developmental stage. Factors influencing the spatial pattern and spatial stability of S. lurida are discussed.

TWO NEW PURSE-WEB SPIDERS OF THE GENUS ATYPUS (ARANEAE, ATYPIDAE) FROM KOREA

Abstract Two new species of the genus Atypus, Atypus sternosulcus new species from Andong and A. suwonensis new species from Suwon, are newly described from Korea.

Insect Fauna of Adjacent Areas of DMZ in Korea

Insect fauna in adjacent areas of Demilitarized Zone (DMZ) in Korea was surveyed seasonally in . The survey area was divided into 3 regions (eastern mountain, middle inland, and western coastal regions) in accordance with administrative districts and topography. Sampling methods such as sweeping, sieving, beating, brushing and suction were used depending on the environmental and military conditions. Total 361 genera and 437 species of 116 families belonging to 14 orders were identified. Among these, 46 species were new to insect fauna of DMZ areas. Species richness was the highest in the eastern mountain region. Numbers of habitat-common and -specific species were 96 (22%) and 195 (47.2%), respectively. The insect species community similarity was highest (0.64) between eastern mountain region and western coastal region. Insect orders showing high species richness were Coleoptera (38.9%), Lepidoptera (19.2%), Orthoptera (9.4%), and Hemiptera (9.2%). These results will be useful information for study of history on the change of insect fauna and future conservation in DMZ areas.

Spiders in a Grape Vineyard in Korea

Abstract Survey was conducted to determine the composition of the spiders in a grape vineyard by using pitfall traps in Sunggeo-eup, Chunan in 1999. Total 17 genera and 19 species belonging to 10 families of spiders were identified. The dominant family was Linyphiidae. Overall, the seasonal fluctuation of the spider population showed two peaks a year. The results showed that the composition of species was very poor and occurrence density was very low in a grape vineyard in this study.