POLLINATION OF NEW CALEDONIAN WINTERACEAE - OPPORTUNISTIC SHIFTS OR PARALLEL RADIATION WITH THEIR POLLINATORS

Flower visitors on 12 species of New Caledonian Winteraceae were studied. The visitors were two species of ancestral moths (Sabatinca; Micropterigidae), three species of weevils (Palontus; Curculionidae), and a species of thrips. Behavior observations and pollen records suggest that the beetles and occasionally the moths serve as pollinators of Zygogynum and Exospermum, and Belliolum is pollinated primarily by thrips. The floral volatiles are simple in composition, usually dominated by short esters. Preliminary experiments showed that ethyl acetate elicited alighting, and a distinctive huddling behavior was elicited by artificially mixed fragrance. The host associations of other Sabatinca and Palontus spp. do not support the hypothesis that the Winteraceae have radiated in association with their pollinators. The available evidence supports the notion of opportunistic isolated host colonizations at some point in the radiation of the pollinator groups. © 1990 Springer-Verlag.