入侵害蟲荔枝椿象（Tessaratoma papillosa, Hemiptera: Tessaratomidae）之越冬棲地偏好研究

Habitat preference of the invasive pest Tessaratoma papillosa (Hemiptera: Tessaratomidae) during overwintering

荔枝椿象是臺灣近年嚴重危害果樹與都市林的外來入侵害蟲，本研究於2019至2020年進行荔枝椿象冬季棲息環境偏好之田間調查。研究結果顯示，荔枝椿象成蟲於越冬期有群聚現象，在龍眼和荔枝的混植園中偏好棲息於龍眼植株。單株層級檢視荔枝椿象於樹冠棲息位置發現，棲息於龍眼樹冠上層處之平均蟲數顯著高於樹冠下層。荔枝椿象成蟲枝條位置分布顯示，以枝條頂端0-30cm部位之成蟲棲息數量最多，與棲息於30-60cm及>60cm的成蟲數呈現顯著差異。整體調查結果顯示，越冬期的荔枝椿象於田間的雌蟲與雄蟲數量差異不顯著，雌、雄蟲在樹冠上層或下層的棲息數量分布亦無顯著差異。荔枝椿象越冬期與交尾期成蟲繁殖器官發育比較發現，越冬期雌、雄成蟲的繁殖器官發育遲緩而尚未成熟。田間調查分析結果顯示，荔枝椿象成蟲具有樹種與樹冠、枝條位置的空間分布之越冬棲息環境偏好，本研究成果有助於提升荔枝椿象冬季防治的成效。

The litchi stink bug, Tessaratoma papillosa (Hemiptera: Tessaratomidae), is an invasive pest in agricultural and urban forest areas of Taiwan. In this study, the habitat preference of the univoltine pest was investigated in the winter seasons of 2019 and 2020. Our results showed that overwintering adult litchi stink bugs exhibited a tendency to aggregate. We recorded a significantly greater abundance of adult litchi stink bugs on Dimocarpus longan (longan) trees than that on Litchi chinensis (litchi) trees in mixed planting orchards during winter. In terms of vertical distribution within the tree, significantly more overwintering adult bugs were collected from the upper layer than from the lower layer of the longan tree crown. The results also showed that the number of adult bugs in the 0–30 cm of the branch tip was significantly more abundance than 30–60 cm and >60 cm. There were no significant differences between the abundances of males and females overwintering adult bugs in the whole tree, as well as upper and lower layers of the crown. Compare to the mating period, the reproductive organs of female and male adults in the overwintering period developed slowly and were immature. In conclusion, T. papillosa exhibited a habitat preference for host plant species, and spatial distribution within branch and crown during overwintering. The results of this study provide great strategic value for better control of this pest, especially during winter.