Psyllids are small sap sucking insects. Around 4,000 species are described worldwide. They show their greatest diversity in the tropical and south temperate zones. Several psyllid species are pest of crops such as citrus, pear, potato and tomato. They has been also responsible for extensive damage to ornamental trees.
In this study, we report four psyllids species, new to Korea: Cacopsylla satsumensis (Kuwayama, 1908) on Raphiolepis indica (Rosaceae), Calophya nigridorsalis Kuwayama, 1908 on Rhus spp. (Anacardiaceae), Carsidara limbata Enderlein, 1926 on Firmiana simplex (Sterculiaceae) and Trioza machilicola Miyatake, 1968 on Machilus thunbergii (Lauraceae). All of them were found as large colonies, severely feeding on host plants, excreting sticky honeydew on which blackish sooty mold grows. Carsidara limbata secrete pale wax masses. Cacopsylla satsumensis cause leaf distortion and Trioza machilicola make galls underside of the leaves.

• Geonho Cho(Laboratory of Insect Biosystematics, Department of Agricultural Biotechnology, Seoul National University)
• Seunghwan Lee(Laboratory of Insect Biosystematics, Department of Agricultural Biotechnology, Seoul National University, Research Institute of Agriculture and Life Sciences, Seoul National University)