Determining the pollinators of rare and endangered Epacris species: implications for conservation

 

Summary of final report on the Australian Flora Foundation funded project:

Karen Johnson and Peter McQuillan
University of Tasmania
December 2012

Grant Details   Final Report

There is little information available on the pollinators of Tasmania’s threatened Epacris species. Our main objective was to determine the pollinators of eight Epacris species; and explore for relationships between pollinators, floral morphology, flowering time and habitat. In completing the objectives we undertook breeding system experiments, quantitatively documented pollinators, collated flowering time and habitat information; and assessed for the potential impact of introduced insects on the native Epacris-pollinator mutualisms. While Epacris species set very little seed in the absence of animals, seed set as a result of animal pollination was successful with up to 30% of capsules containing numerous viable seeds. Epacris species have generalised pollination systems attracting at least 33 different pollinators, including flies, bees and butterflies. Four introduced species also visited Epacris: honey bee, bumble bee, drone fly and cabbage white butterfly. The introduced drone fly and cabbage white butterfly have not previously been recorded as pollinators of the native flora of Tasmania. No statistically significant relationship was found between pollinators, floral attributes, flowering time or habitat. However, the introduced honey bee was the most frequent visitor to many Epacris species and its potential to impact on the native Epacris-pollinator relationships is discussed.