Assessment of pollen assemblages from the hives of <i>Tetragonula carbonaria</i> for the presence of the threatened species <i>Grevillea parviflora</i> subsp. <i>parviflora</i>

Abstract

Pollen assemblages from managed hives of the Australian social stingless bee Tetragonula carbonaria were examined for the presence of the threatened species Grevillea parviflora subsp. Parviflora. Managed hives of Tetragonula carbonaria were placed in bushland at Lake Macquarie, New South Wales, Australia, in four known populations of Grevillea parviflora subsp. parviflora through the main flowering period of 12 September to 2 November 2014. Samples of honey and propolis were collected from the hives at the end of this period and analysed using palynology techniques for the presence of Grevillea parviflora subsp. parviflora pollen. Grevillea parviflora subsp. parviflora pollen was detected in all propolis samples from the four study sites but was not found in the honey samples. Field observations identified that honeybees were the dominant insect visitor to Grevillea parviflora subsp. parviflora at all sites. There were no sightings of Tetragonula carbonaria foraging on Grevillea parviflora subsp. parviflora inflorescences during field observations. This study also demonstrates the application of managed hives of the Australian stingless bees Tetragonula carbonaria for monitoring floral diversity where propolis samples can be used to indicate plant species richness (biodiversity) and the presence of specific species relevant to conservation within their foraging area.