THE ROLE OF BUMBLEBEES AS POLLINATORS OF RED CLOVER AND LUCERNE IN NEW ZEALAND: A REVIEW AND PROSPECT

Abstract

Four species of bumblebees, Bombus horforum, B. ruderafus, B. subterraneus and B. terrestris, are now established and widespread in New Zealand. The long-tongued species, B. hortorum, B. ruderatus, and B. subterraneus, are very effective pollinators of red clover but not of lucerne. Bombus terrestris is short-tongued, "robs" red clover, and is thus less effective as a pollinator of this crop but is a most efhcient pollinator of lucerne. Research on bumblebees in New Zealand was first concerned with identification of the species and their distribution. Since the 1950s biological aspects have received increasing attention and success has been achieved with local enhancement of bumblebee populationsintroduction of B. horforum to Manawatu district and increase of local populations in Mackenzie Country. It is considered that manipulation of populations of the species now present offers most promise for increase in pollination, and hence seed yield, of red clover and luccrne in New Zealand.