Objective We aim to produce a more comprehensive and scientific catalog of invasive insect pests in forest and grassland ecosystems of the Chinese mainland. This study also summarized their main invasion characteristics, providing information to support the national survey, prevention and control of invasive species.

Method Through information retrieval and species screening method, we screened species based on classification principles of invasive alien species, geographical distribution, origin, host plant, and the first report of invasion in China. We compiled a catalog of invasive insect pests feeding on and adversely affecting forest trees, fruit trees, ornamental flowers, and herbaceous plants in forest and grassland ecosystems of the Chinese mainland, which were introduced from foreign regions. We conducted a comparative analysis with existing cataloging studies to eliminate any inaccurately reported species. Furthermore, we examined the proportion of taxa, as well as biological and invasion characteristics of these invasive pests.

Result (1) We compiled a catalog of invasive insect pests in forest and grassland ecosystems of the Chinese mainland, identifying a total of 110 species. We excluded 26 native species and 11 species that had not been introduced to the Chinese mainland, which were previously documented in earlier research. Additionally, we noted 19 new species. (2) Our analysis of taxonomic proportions indicated that the orders Hemiptera and Coleoptera collectively represented nearly two-thirds of the listed species at the order level. Pseudococcidae exhibited the highest species richness at the family level, while the genera Cryptotermes and Phenacoccus were found to encompass the most species at the genus level. (3) 54.5% of invasive pests were polyphagous species. The host plants that supported a relatively high diversity of monophagy and oligophagy invasive pests included those from Pinaceae, Arecaceae, and Eucalyptus. The primary origins of all invasive pests were traced back to the Americas, followed by Southeast Asia and South Asia. (4) Since the 21st century, there has been a marked increase in invasive pests, with a notable acceleration in the invasion rate. The highest number of invasive pest species found for the first time were in Guangdong Province, Hainan Province, Beijing, Yunnan Province, Shandong Province, Shanghai, Xinjiang Uygur Autonomous Region, and Guangxi Zhuang Autonomous Region, collectively accounting for 80% of the overall first discoveries.

Conclusion The compilation of invasive insect pests identified within the forest and grassland ecosystems of the Chinese mainland in this study can be leveraged for various purposes, including pest surveys in these ecosystems, national surveys of invasive species, the cataloging of invasive species, and facilitating international communication. The methodology utilized in this research, which encompasses the retrieval of information resources, as well as the screening, confirmation, and exclusion of invasive species, may serve as a valuable reference and be applicable to the cataloging efforts of other invasive alien species.