Limnebius water beetles exhibit exceptionally high diversification of male genitalia but a uniform external appearance. We examined a connection between the magnitude of interspecific variability in each subgroup and static allometry between male genitalia and body size. Several lineages with simple genitalia show low diversification of body and male genitalia. High magnitude is caused by diversification among lineages with different complexity compositions of male genitalia and clusters of species with small and large body sizes. In the Limnebius parvulus group high intraspecific variability corresponds between the coefficients of static allometry, size of male genitalia, variabilities of female body size, indicating a role of the females in the selection of wide and long male genitalia. The general evolutionary trend of the genera fits with the superposition of all intraspecific allometries. It is usually neutral; negative is associated with local picks of the male genitalia complexity, featuring a trade-off between size and complexity, reflected in the magnitude of the corresponding values, Positive was observed only on the populational level, with negative allometry in the same species in a rapidly evolving species complex in the L. nitidus group. The L. nitidus subgroup exposes the highest magnitude of the male genitalia complexity and the ventral area, evolving faster than length. Intraspecific heterogeneity is also featured by two specimens with long genitalia in species from the same subgroup, with the simplest male genitalia in its subgenera. The phylogenetic position of both heterogeneous species featuring abrupt changes in male genitalia illustrates macroevolution on a microevolutionary level.

Despite centuries of exploration, our perception of potential mechanisms determining the species community assemblage is still in infancy . Longhorn beetle as an insect with larval stage feeds on the xylem of plants or trees, the relative importance of biotic (host-specificity) and abiotic (climate gradients) processes to determining their community compositional variation is unknown. In the aim of exploring the knot, we therefore designed the experiment throughout multiple spatial scales (macro/regional and micro/local) along tropical to temperate climate gradients at the Indo-Burma biodiversity hotspot, to examine to what extent biotic and abiotic factors may exert a significant influence on longhorn beetle species composition assembly, and whether this relationship is scale dependent. The relationships between longhorn beetles species composition variation and biotic and abiotic factors were examined using β-dissimilarity indices comparison，NMDS analysis , variation partitioning based on RDA, linear mixed-effect model and mantel test. We found a positive relationship between the species compositional variation of both beetle and plants, in which longhorn beetle species dissimilarity apparently track changes in plant dissimilarity both at macro/regional and micro/local scales. NMDS analysis showed that abiotic factors have prominent influence to the longhorn beetle community assemblage. Variation partitioning and linear mixed-effect model retained significantly correlated Environment and plant diversity metrics for beetle diversity. Thus, we concluded that: 1) biotic and abiotic factors collaboratively shaped longhorn beetle community composition along various spatial scales; 2) the relative importance of abiotic and biotic variation explaining the longhorn beetle community composition vary by spatial scale; and 3) biotic interactions have prominent effect to longhorn beetle community composition at local-scale while macroclimatic gradients impose the most control on it at macro-scale. Besides, our study showed that the influence of dispersal limitation in the species assembly of longhorn beetles from tropical to temperate area was minor compared with plant communiti