University campuses, as small and isolated areas of rapidly growing urban areas, can provide a unique opportunity for urban biodiversity research, conservation, education, and citizen science by monitoring assemblages of butterflies within their areas. We surveyed butterfly biodiversity in a rapidly developing urban area represented by the Chenggong Campus of Yunnan University in southwestern China using the Pollard walk method. In total, 3625 butterfly individuals belonging to 50 species, 35 genera, and six families were recorded in this survey. The results showed that the families Pieridae and Nymphalidae are the families with the highest species richness on the campus, and that the family Riodinidae contained the fewest species. Pieris rapae was the most common species, and seven species assessed by the IUCN Red List were recorded. Butterfly community structure varied across habitats and seasons on campus, and butterfly diversity was higher in spring and autumn than it was in summer and winter, as well as being higher in road habitats than in scenic habitats. Unavoidable urbanisation activities (construction, green space planning, etc.) may have influenced the composition and diversity of butterflies, and conserving urban butterfly diversity requires a balance between urban planning and habitat diversity. Finally, we encourage universities and research institutions to develop butterfly monitoring platforms for citizen scientists to participate in.

Acorn weevils critically impact forest regeneration in semi-humid evergreen broad-leaved forests (SEBFs) by parasitizing and consuming acorns before dispersal. Despite their ecological significance, research on the species diversity of acorn weevils within SEBFs remains limited. To address this gap, we assessed the species diversity and host affinity of acorn weevils across six dominant oak species at 18 locations. We performed DNA extraction and mitochondrial COI gene sequencing on weevil larvae and analyzed acorn functional traits (AFTs) from host acorns. Six acorn weevil species across four genera and two families were identified within the dominant acorns of SEBFs. Curculio dentipes showed the lowest host specificity, while Niphades castanea and Cyllorhynchites ursulus were specialist species. Notably, the species diversity of acorn weevils was significantly lower in Quercus franchetii than in others. Acorn volume and three secondary metabolite contents, including total phenols, total flavonoids, and tannins, were the primary AFTs influencing weevil species diversity. This study not only advances our comprehension of acorn weevil species diversity and their ecological interactions with oak hosts, but also provides valuable insights for the ecological management of SEBFs in southwest China.

Acorns are crucial for the regeneration and stability of oak forest communities, yet they often suffer significant predation by weevils before dispersal. Understanding the interaction between acorn functional traits and weevil infestation is essential for elucidating plant‐insect coevolution. This study examined the relationship between acorn functional traits and weevil infestation rates in six dominant Fagaceae species ( Quercus schottkyana , Q. delavayi , Q. franchetii , Castanopsis delavayi , C. orthacantha and Lithocarpus dealbatus ) in semi‐humid evergreen broad‐leaved forests in Yunnan, China. The results showed significant interspecific variation in acorn traits and infestation rates. L. dealbatus had the lowest infestation rate (9%), associated with its thick pericarp (0.88 mm), while Quercus species with higher levels of secondary metabolites (total phenols, flavonoids and tannins) exhibited higher infestation rates (34%–51%). Castanopsis species maintained moderate infestation rates with a combination of moderate physical defences and high starch content. Mixed‐effects models revealed that morphological and chemical traits together explained 38% of the variation in infestation rates, with pericarp thickness and tannin content being key inhibitory factors. Infested acorns upregulated secondary metabolite concentrations as a defensive response, reflecting phenotypic plasticity. Standardised major axis regression confirmed stable trade‐offs between physical and chemical defences, as well as between defence compounds and nutrient reserves. Even in the absence of weevil infestation, resource allocation strategies were inherent. We propose a three‐tier defence model: physical barriers (pericarp/cicatrix), chemical defences (total phenols/tannins) and nutrient regulation (starch reallocation). These complementary strategies collectively maintain forest community stability. The study provides new insights into plant–animal coevolution and supports conservation efforts for semi‐humid evergreen broad‐leaved forests.