Jong Kook Jung

A comparison of spider communities in Bt and non-Bt rice fields.

ABSTRACT To assess the potential adverse effects of a Bt rice line (Japonica rice cultivar, Nakdong) expressing a synthetic cry1Ac1 gene, C7-1-9-1-B, which was highly active against all larval stages of Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Crambidae), we investigated the community structure of spiders in Bt and non-Bt rice fields during the rice-growing season in 2007 and 2008 in Chungcheongnam-do, Korea. Spiders were surveyed with a sweep net and suction device. Suction sampling captured more spiders, measured in terms of species level and abundance, than sweeping. Araneidae and Thomisidae were captured more by sweeping, and certain species were captured only by sweeping. These findings show that both suction and sweep sampling methods should be used because these methods are most likely complementary. In total, 29 species in 23 genera and nine families were identified from the 4,937 spiders collected, and both Bt and non-Bt rice fields showed a typical Korean spider assemblage. The temporal patterns of spider species richness and spider abundance were very similar between Bt and non-Bt rice, although significant differences in species richness were observed on a few occasions. Overall, spider community structure, including diversity, the dominant species, and abundance did not differ between Bt and non-Bt rice. The results of the study indicated that the transgenic Cry1Ac rice lines tested in this study had no adverse effects on the spider community structure of the rice fields.

Spider Fauna of Island Geojedo (Prov. Gyeongsangnam-do) in Korea

This work was conducted to investigate spider fauna and community structure of Geojedo situated at the southern coast of Gyeongsangnam-do, South Korea. Seventy species of 48 genera belonging to 17 families were identified from 389 collected spiders. Check list of spiders which represent 137 species, 91 genera from 29 families was made from former reports and present work including 4 cosmopolitan species, 6 Holarctic species, 13 Palearctic species and 2 Korean endemic species. Species richness was high in Araneidae (30 species, 21.9%), Salticidae (22 species, 15.8%), Theridiidae (18 species, 12.9%), and Thomisidae and Linyphiidae (10 species, 7.2%) in order. This work might be valuable monitoring to understand the biota of Geojedo and to analyze Korean island ecosystem.