The Genus Rhynchaenus Clairville, known as a significant pest group with distribution of worldwide. 40 and 11 species were reported in Japan and China, repectively. Members of Rhynchaenus are usually known as flea weevils and leaf-miners on laval stage. While working on Insects founa of Island, we discovered one species, which is a newly added to the Korean founa (Rhynchaenus maculosus Yang & Zhang). This species was newly emerging pest severely Oak in China. The diagnosis, photographs of habitus and diagnostic characters are provided to facilitate identification.

This study was carried out to clarify the biologies and morphological characteristics of Rhynchaenus sanguinipes. Also some chemicals were tested to screen the effective insecticide for the control of the species. Up to date, Zelkova serrata has been known as host plant of Rhynchaenus sanguinipes, which shows serious damage in this country. In the present study, Ulmus pumila was first found as host plant in this study. Body lengths of larvae, pupa and adult were 4.53±0.30 ㎜, 3.30±0.42 ㎜ and 2.96±0.12 ㎜, respectively. The overwintered adult of the species emerged on early April to late April, and adult of next generation emerged on early May to late May. Pupal periods were 10, 7.2, 5.1 and 4 days on 16, 20, 24 and 28℃, respectively. The lower developmental threshold temperature was 5.8℃. Four braconid parasitoids were found as natural enemies, which emerged mainly on late April to early June. Insecticidal activities with treatments of fenitrothion 50% EC, indoxacarb 30% WG, ethofenprox 20% EC and thiacloprid 10% SC was investigated against adult of R. sanguinpes, and they showed ＞90% mortality.