Abstract: Objective To investigate the ecological niches of sucking lice (Phthiraptera: Anoplura) on the body surface of small mammal hosts and the co-evolutionary relationship between lice and mammal hosts in Yunnan Province. Method Thirty species of small mammals were captured and used as 30 resource sequences. The distribution and composition of the dominant 22 species of sucking lice on the body surface of the 30 species small mammal hosts were analyzed as the utilization proportion for each resource sequence. The niche breadth and proportional similarity were measured. SPSS 13.0 statistical software was used for analyzing the niche overlap matrix of sucking lice by hierarchical clustering analysis, and a dendrogram was made. Results The niche breadth was narrow for most species of sucking louse. Among the detected species, Hoplopleura pacifica showed the widest niche breadth, but only 0.1536. Indices of niche proportional similarity of most sucking lice were relatively small from 0.0005 to 0.4695. The 22 species of sucking lice were classified into 16 niche overlap groups, by λ=5.5, through a hierarchical clustering analysis for the niche overlaps, and the clustering process of most sucking lice was late. Conclusion The sucking lice have a high specificity for hosts, of which different species show an apparent niche divergence on host selection. The results reveal a high coevolution between sucking lice and the mammal hosts.

Key words: Anoplura, Sucking louse, Niche, Coevolution, Small mammal