Thrips (Thysanoptera) pollination in Australian subtropical rainforests, with particular reference to pollination of Wilkiea huegeliana (Monimiaceae)

Approximately 23 species of thrips were recorded from flowers of 26 species of Australian subtropical rainforest trees, shrubs and vines (in 17 famili es) in the Manning Valley, coastal northern New South Wales. Pollination by thrips (thripophily) appears more widespread in rainforest communities tha n has been previously recognized. The pollination ecology of Wilkiea huegel iana (Monimiaceae) was studied in detail. Wilkiea huegeliana is a small, un isexual, annually flowering tree or shrub of rainforest and associated ecot ones in eastern Australia, and is a larval food plant for the Regent Skippe r butterfly Euschemon rafflesia rafflesia (Hesperiidae). At this latitude W . huegeliana is pollinated solely by a species of thrips, Thrips setipennis , but T. setipennis is not restricted to W. huegeliana and was recorded fro m flowers of 13 rainforest plant species. It appears to be the obligate pol linator also for Rapanea howittiana and R. variabilis (Myrsinaceae). Pollin ator exclusion experiments were inconclusive but W. huegeliana may be facul tatively agamospermous. The recruitment pathway to unrewarding female W. hu egeliana flowers is uncertain but attraction may function by automimicry. B oth male and female flowers serve as brood sites for T. setipennis larvae. Although the pollination ecology of W. huegeliana is specialized, the famil y Monimiaceae exhibits a broad diversity of pollination strategies. A numbe r of these are discussed. The apparent obligate and restricted pollinator r equirements of W. huegeliana may make it, and any associated phytophagous f auna, vulnerable to the impacts of habitat fragmentation.