MARCH GENERAL MEETING –KRM BRANCH
The guest speaker for our March meeting was Dr Terry Houston, Research Associate in the Department of Terrestrial Zoology (Entomology) at the WA Museum.
Terry started his presentation by saying that many of the classical characterisations of Australia’s native bees have been subject to disruption in recent times. The disruption is a result of the developments in DNA technology that enable genus and species linkages to be re-tested. For many years the book ‘Bees of the World’ by Charles D. Michener was the bible for those studying bees. However, those using DNA to study bees have now undone some of this work. The ‘villain’ leading this disruption is Dr Eduardo Almeida from Sao Paulo, Brazil.
To explain the impact that this disruption has had on the classical characterisation of Australian bees Terry discussed the hairy Colletids. Historically these are broken down into Colletinae (which is then broken down into the Colletini and the Scraptrini, the latter including the Paracolletes, e.g. Paracolletes crassipes Smith 1853, Swan River) and Diphaglossinae (which are found in South America). DNA studies now put Paracolletes crassipes in the Diphaglossinae. Diphaglossinae are known to make cocoons, so the hunt is on to find a Paracolletes crassipes nest or burrow to see if they make a cocoon; however, none has been found so far.
Terry then discussed another subfamily, the Trichocolletes. They are pollinators of pea flowers and Terry showed a photo of a Trichocolletes sp. on a pea flower and described a study of what he called ‘a very perplexing bee’. He showed a diagram of a normal nesting burrow and brood cell. Bees carry in pollen and lay eggs. The hatched larva feeds on the pollen cache – Terry showed a photo of a larva and explained that the larva eats all the pollen and only then does it excrete any waste. Terry was informed of a breeding site for Trichocolletes in Yanchep National Park. He visited in November and dug up some soil and then sieved it. He found brood cells and was surprised to find that the larva was still wet. There was foam on the edge of the brood cell but how it was formed and by whom (adult or larva) remains a mystery. He found that the larva produces a yellow oil from the pea flower pollen. Further investigation in February showed that the larva had turned into a black form (a pharate adult) and in May the young adult forms emerged from the burrow allowing the species to be identified: it was Trichocolletes orientalis (an eastern Australian species not previously known in WA). Terry noted that the only forage plant available in Yanchep National Park for this species was Hardenbergia comptoniana.
Discussions of other studies continued, and Terry showed some photos of several other native bees, ending up with a discussion about Sugar Bag stingless bees. This interesting presentation highlighted the fact that there is still a lot to discover about our native bees. There were many questions from the audience showing the level of interest in Terry’s presentation and more generally in our native bees.