New record of the genus Hydronaphis (Hemiptera: Aphididae) from Korea: A root feeding aphid on Impatiens textori (Balsaminaceae)

Hydronaphis impatiens Shinji, 1922 is recognized for the first time in Korea. Some colonies of H. impatiens have been collected on Impatiens textori Miq. in Pyeongchang, Gangwon-do. Hydronaphis impatiens has a novelty in its biology feeding on subterranean parts, stem-bases and roots, of the host plants. The genus Hydronaphis consisting of five species have recorded living on roots of the host plants. It is redescribed, illustrated, and measured for the apterous and alate viviparous females.