New Host Plant Records for Heteroptera (Hemiptera) Species: Feeding Behavior on the Thistle (Gundelia sp.) Plant

ABSTRACT: This study was conducted in 2021 in the Karacadağ region, within the boundaries of Diyarbakır (Bağlar, Ergani, and Çınar districts) and Şanlıurfa (Siverek and Viranşehir districts) provinces, to investigate the Heteroptera (Hemiptera) species associated with the Thistle plant (Gundelia sp.). The research aimed to identify both pest and predatory insect species found on the plant and assess their ecological roles. Through systematic field and laboratory studies, seven species from the Heteroptera suborder were identified on Gundelia sp. Among them, five species were classified as pests due to their feeding activities on the plant, while two species were predatory, contributing to natural biological control. The pest species identified were Carpocoris coreanus Distant, 1899, Carpocoris pudicus (Poda, 1761), Dolycoris baccarum (Linnaeus, 1758), Codophila varia (Fabricius, 1787) (Pentatomidae), and Odontotarsus purpureolineatus (Rossi, 1790) (Scutelleridae). The predatory species recorded were Orius laevigatus (Fieber, 1860) and Orius vicinus (Ribaut, 1923) (Anthocoridae). The study revealed that except for Dolycoris baccarum, all other species were recorded feeding on the Thistle plant for the first time. The highest population density was observed for Dolycoris baccarum, which primarily fed on the fresh seed parts of the plant. Other pest species were also found feeding on the seeds and leaves, potentially affecting the plant’s growth and seed viability. These indings contribute to the understanding of insect-plant interactions in the Karacadağ region and highlight the importance of conserving the Thistle plant’s natural habitat. Additionally, Dolycoris baccarum was noted as a key species in this ecosystem, possibly playing an indirect role as an alternative host for parasitoids of Eurygaster integriceps, a major pest in wheat and barley cultivation. Therefore, preserving Thistle-rich areas could have significant implications for biodiversity conservation and agricultural sustainability in the region.