This study was conducted to surveyed the community structure of insects on thirty varieties of Hibiscus syriacus in Busan and Suwon, Korea. In addition, seasonal changes and damage rates of major insect pest species were investigated. Insect pests were visually observed from the area of H. syriacus plantations. As a result, 16 species belonging to 9 families of 4 orders were observed, while 13 species were classified to insect pests. Among insect pests, hemipterans (6 species) and lepidopterans (4 species) were most diverse groups. During summer season, Rehimena surusalis (Lepidoptera: Crambidae) and Haritalodes derogate (Lepidoptera: Crambidae) were damaged to flower buds and leaves, respectively. In September, nymphs and adults of Plautia stali (Hemiptera: Pentatomidae) were found from flower buds and leaves.

The genus Tilia is characterized by linear form bracts of which the lower part is attached to the peduncle of a cyme. This character is distinguished from the others genus of Malvaceae. The purpose of this study is verifying the phylogenetic relationship of genus Tilia. Phylogenetic analyses were conducted to evaluate relationships of 10 taxa of Tilia in Korea and Japan including one outgroup (Gossypium hirsutum). The molecular phylogenetic analyses were conducted with sequences based on ITS, trnL-F and rpl32-trnL region. The combined data result of ITS, trnL-F and rpl32-trnL was formed by 6 clades. T. kiusiana situated as the most basal clade. T. amurensis, T. taquetii and T. rufa are composed a clade. T. koreana, T. insularis and T. japonica was formed independent clade. T. insularis has the closest relationship with T. japonica. T. miqueliana, T. mandshurica, and T. megaphylla are composed a clade and showed a sister relationship than other species.