Reproductive isolation of Apis nuluensis Tingek, Koeniger and Koeniger, 1996 by species-specific mating timeN. Koenigera, G. Koenigera, M. Griesa, S. Tingekb and A. Kelitub
a Institut für Bienenkunde (Polytechnische Gesellschaft), Fachbereich Biologie der JW Goethe-Universität Frankfurt aM, Karl-von-Frisch-Weg 2, 61440 Oberursel, Germany
b Agricultural Research Station, Lagud Seberang PO Box 197, 89908 Tenom, Sabah, Malaysia
Abstract - The recent discovery of a morphologically distinct Apis type in mountain areas of Sabah raised the question of its taxonomic status. After it became evident that the drone flight period did not coincide with other cavity dwelling Apis species of Borneo, a new species, Apis nuluensis was described (Tingek et al, 1996). Here drone flight observations and results are reported in detail. A total number of 255 drone flights (50-60 drones) were observed at one colony. The drones started to fly at 1044 hours and the flight activity reached a peak shortly after 1200 hours. The last drones flew at 1312 hours. The complete separation of A nuluensis drone flight time from the other two cavity dwelling Apis species of Borneo functions as a premating barrier and results in complete reproductive isolation. This seems to be significant because overlap of habitats occurs in the transition zone of the upper dipterocarp forest and lower mountain forest (between 1 500m to 1 700m).
Key words: Apis nuluensis / reproductive isolation / drone flight / Borneo