Molecular Identification of Insects on Imperata cylindrica (Poales: Poaceae) and Exploration of Potential Natural Enemies Using DNA Barcoding

Imperata cylindrica is a highly invasive grass that causes severe ecological and agricultural damage worldwide, yet effective and sustainable management options remain limited. In this study, we investigated insects associated with the stems and rhizosphere soil of I. cylindrica in four parks in Beijing, China, and evaluated the utility of DNA barcoding for species identification and natural enemy discovery. A total of 16 insect samples were collected, and the mitochondrial COI gene was amplified using universal (LCO1490/HCO2198) and degenerate (KC-COI-F/R) primers. High-quality sequences were obtained from 12 of the 16 individual specimens, representing two classes (Insecta and Symphyla), two orders (Diptera and Coleoptera), and five families (Chloropidae, Muscidae, Rhiniidae, Eumolpidae, and Scutigerellidae). Chloropidae larvae (Diptera) dominated the stem-associated samples, and Pseudocolaspis sp. (Coleoptera: Eumolpidae), Atherigona orientalis (Diptera: Muscidae), Rhyncomya pruinosa (Diptera: Rhiniidae), and a species of Scutigerellidae (Symphyla) were also identified. BLAST analysis assigned the chloropid sequences to Chloropidae sp. BIOUG02404-H03 with 96.93–97.34% identity, and these sequences were recovered from stems at all four sampling sites. These results demonstrate that DNA barcoding effectively identifies morphologically challenging immature stages and soil-dwelling specimens. The abundant chloropid larvae, which feed internally in I. cylindrica stems, represent a promising candidate for further host-specificity testing as a classical biological control agent. This study provides the first molecular characterization of insects associated with I. cylindrica in Beijing and highlights the value of DNA barcoding in biocontrol resource discovery.