University of Guilan Caspian Journal of Environmental Sciences 1735-3033 24 1 2026 01 01 Parasitoids of the genus Trissolcus as biological control agents of the brown marmorated stink bug (Halyomorpha halys Stål) in Kazakhstan 187 194 9490 10.22124/cjes.2026.9490 EN Gulnaz Mengdibayeva LLP "Kazakh Research Institute of Plant Protection and Quarantine named after Zh. Zhiembayev", Almaty, Kazakhstan Nurzhan Mukhamadiyev LLP "Kazakh Research Institute of Plant Protection and Quarantine named after Zh. Zhiembayev", Almaty, Kazakhstan Kanat Anuarbekov Kazakh National Agrarian Research University, Almaty, Kazakhstan Nurbakyt Kurmangaliyeva LLP "Kazakh Research Institute of Plant Protection and Quarantine named after Zh. Zhiembayev", Almaty, Kazakhstan Yelshat Dauletkeldi LLP "Kazakh Research Institute of Plant Protection and Quarantine named after Zh. Zhiembayev", Almaty, Kazakhstan Nurgeldi Kenges LLP "Kazakh Research Institute of Plant Protection and Quarantine named after Zh. Zhiembayev", Almaty, Kazakhstan Assel Seitzhan LLP "Kazakh Research Institute of Plant Protection and Quarantine named after Zh. Zhiembayev", Almaty, Kazakhstan A.E. Koigeldina LLP "Kazakh Research Institute of Plant Protection and Quarantine named after Zh. Zhiembayev", Almaty, Kazakhstan Gaziza Sarsenbayeva LLP "Kazakh Research Institute of Plant Protection and Quarantine named after Zh. Zhiembayev", Almaty, Kazakhstan Journal Article 2026 02 28 The brown marmorated stink bug (Halyomorpha halys Stål) is a quarantine invasive pest capable of causing significant economic losses in agricultural and forest ecosystems. In Kazakhstan, this species was first recorded in 2016 on agricultural and forest plantations, prompting comprehensive monitoring of its distribution and the assessment of its potential threat to fruit, vegetable, ornamental, and forest plants. During 2024-2025, surveys in the southern and southeastern regions of Kazakhstan, including Almaty city, Almaty, Turkestan, and Kyzylorda Regions, investigated Trissolcus parasitoids as potential biological control agents of H. halys for the first time. The primary objectives were to identify the species composition of egg parasitoids, evaluate their biological effectiveness, and assess their suitability for using H. halys as a host. Field studies employed pheromone traps, manual collection, and visual plant inspections. Laboratory experiments examined the parasitoids’ life cycle, the duration of preimaginal development, parasitism rates of egg masses, and adult emergence. Morphological identification was corroborated using molecular genetic methods with COI and ITS marker genes. Two parasitoid species were detected – Trissolcus japonicus and Trissolcus semistriatus – demonstrating high parasitism rates (86.3-89.6%) and successful adult emergence (>92%). The highest densities of H. halys were recorded on apple (Malus domestica), paulownia (Paulownia spp.), and northern catalpa (Catalpa bignonioides), indicating stable population reproduction in the region. The duration of preimaginal development and the average adult lifespan of the parasitoids confirm their suitability for mass rearing under laboratory conditions. These results highlight the strong potential of Trissolcus spp. as biological control agents of H. halys in agricultural and forest ecosystems in Kazakhstan, and underscore the importance of molecular identification in studying beneficial insect biodiversity. https://cjes.guilan.ac.ir/article_9490_2980e102c26f0523905e98595afcbe95.pdf