The morphometric position of Apis nuluensis Tingek, Koeniger and Koeniger, 1996 within cavity-nesting honey bees

Morphological features of nine samples of Apis nuluensis collected at the region of Sabah, Borneo, Malaysia in mountainous areas ranging from 1 524 to 3 400 m were analysed using 38 characteristics. Seventeen measurements of sizes, ten of coloration and hairyness, and 11 of wing venation angles were measured according to the methods of Ruttner et al (1978). The morphological position was evaluated within a frame containing other cavity-nesting Apis species drawn from the Oberursel data bank (Apis cerana from four Asian locations, Apis koschevnikovi, Apis nigrocincta and two equatorial Apis mellifera races). A nuluensis shows some extreme characteristics which separate it from all other cavity-nesting bees, or all A cerana groups. In size measures it is closest to A nigrocincta from Sulawesi, while wing venation measures are close to the northern A cerana groups. Factor analysis showed A nuluensis to be clearly and significantly distinct from each of the other groups on at least two of the first three principal component axes. In discriminant analysis, all A nuluensis samples were assigned to their group with high probability. In particular, A nuluensis clearly differed from the sympatric groups, A cerana from Borneo and A koschevnikovi. In relation to A cerana in general, and to the sympatric A cerana from Borneo, this distinctness is less pronounced than that of A koschevnikovi, while the results from wing venation angles alone gave the opposite result