ECOLOGY AND BEHAVIOUR OF THE BEE AMEGILLA (ASAROPODA) DAWSONI (RAYMENT) WITH NOTES ON A RELATED SPECIES (HYMENOPTERA ANTHOPHORIDAE)

WA Museum Records and Supplements | Updated 1 decade ago

Abstract: Amegilla dawsoni, Australia's largest anthophorine bee, annually produces a single generation from July to September. Females nest solitarily or more often gregariously in flat, hard, bare clay, apparently using nectar to soften the soil during excavation, Each burrow is furnished with a mud turret which is demolished when the nest is complete, Nest structure is described in detail.

Larval provisions are liquid. After consuming their provisions, larvae eat the wax lining of their cells, defaecate and enter a diapause which may last for one or more years. They do not spin cocoons.

Mating occurs at nesting areas and at the forage plants. Males vary conspicuously in size and exhibit a bimodal size frequency distribution. Large size appears to be an advantage to males eompeting for access to newly emerging virgin females at the nesting sites. Small males predominate amongst the 'patrollers' at forage plants.

A miltogrammine fly and a mutillid wasp were observed to develop at the expense of the bees in their brood cells, The bees swarm about intruders (humans and corvids) at nesting aggregations but do not attack them.

Brief observations on the nests and behaviour of a second, undescribed species of Asaropoda are also recorded.

The biology of Amegilla (Asaropoda) is briefly discussed and compared with that of other Anthophorini.