Morphological diversity of ground beetles (Coleoptera: Carabidae) in Scottish agricultural land

Abstract

The morphospace defined by 87 species of ground beetle (Coleoptera: Carabidae) of Scottish non-forested habitats is described with multivariate methods, using 13 linear quantitative measurements of the body, hind legs, eyes and antennae, plus five qualitative characters concerned with body shape, colour, wing development, and pubescence. Relationships between pairs of variables are studied with phylogenetic independent contrasts, using two different taxonomic classifications as an approximation to the phylogeny of the group. The first ordination axis of the morphospace was found mainly to reflect the positive correlation between length of the antennae and length of the hind legs, the second to reflect the width of the head, diameter of the eye and pronotum height, and the third the width of the pronotum and elytra, length of the metatrochanter and width of the metafemur. The principal relationships involving qualitative characters were between colour of the body and legs and shape of the pronotum with ordination axes, wing development with width of the elytra, and pubescence with colour of the legs. Most correlations between quantitative variables, in particular those most influencing the ordination axes of the morphospace, remained significant when measured with phylogenetic independent contrasts using both classifications. Independent contrasts comparing qualitative with quantitative variables or ordination axes were only significant for the colour of the body with the second axis for both classifications used, and length of the antennae with colour of the body and shape of the pronotum for only one of the classifications. The main morphological trends within the morphospace defined are related with published information on their performance, in particular running speed and pushing abilities, following previous work on the functional morphology of the group. The morphospace defined by the species studied is a fundamental tool that will allow further investigations on the relationships between their morphology and life traits, as well as on the relationships of the functional diversity thus characterized with environmental correlates.