New occurrence of the invasive alien leaf-footed bug Leptoglossus gonagra (Hemiptera: Coreidae) in South Korea.
The invasive alien leaf-footed bug Leptoglossus gonagra (Fabricius 1775), native to the Americas, is herein recorded from South Korea for the first time. Forty nymphs and adults were collected on 22 September 2016 from arable lands of two separate sites. These individuals were identified based on the analysis of morphological characters and cytochrome oxidase c subunit 1 sequences. A neighbor-joining tree indicated the existence of two clades: Group A from Brazil, and Group B from Asia and Oceania. Mean genetic distance between clades was 8.11%, range 7.60-8.57%. Within clades, mean genetic distance was 0.42% (0.17-0.83%) in Group A and, 0.45% (0.00-0.83%) in Group B. Colonies of 2nd-final instar nymphs and adults were found, on top of leaves, flowers, fruits, and between the stems of pumpkins (Cucurbita moschata). Nymphs and adults damaged host plants by sucking their leaves, stems, fruits, and buds. After the first discovery in 2016, we were unable to find the bugs again (in 2017-2019). Therefore, the invasion of this species seems to have occurred only temporarily, during the warm season. We suggest that the species may have failed to overwinter as it is normally distributed in regions warmer than Korea. Nevertheless, possible appearances of this species must be continuously monitored as it is a potential pest of various plants cultivated in South Korea.