eastern Victoria Julian Brown Australian National University - PowerPoint PPT Presentation

Native bees on crops in eastern Victoria Julian Brown Australian National University

Outline • Native Victoria bees visiting crops. • Native vegetation and Victorian bees. • Making nests for Victorian bees.

Study area Exoneura on Rubus. Photo credit: Alison Hoelzer • 6 x orchards (mostly apple, some cherry) • 7 x berry farms (blueberry, raspberry, blackberry) • 7 x forest sites

Victorian bees visiting crops

Crop visitation Apple Red reed bee (Exoneura sp.) Black reed bee (Exoneura sp.) Cherry White-banded bee (Lasioglossum sp.) Lasioglossum Raspberry parasphecodes sp. and blackberry Homalictus sp. Lipotriches sp. Blueberry This figure shows the Victorian bees, on the left, that I found visiting these crops on the right. A line connecting a bee to a crop indicates that I’ve seen that bee visiting that crop. The thickness of these lines is roughly proportional to the frequency of visitation, with thicker lines indicating more frequent visitation of that crop by that bee.

Native vegetation and Victorian bees

Nesting substrate Red reed bee (Exoneura sp.) Black reed bee (Exoneura sp.) White-banded bee (Lasioglossum sp.) Lasioglossum parasphecodes sp. Homalictus sp. Lipotriches sp. Reed bees nest in pithy stems of things like tree ferns and bramble. All the other bees found visiting fruit crops nest in the soil.

Floral resources Natives Red reed bee (Exoneura sp.) Black reed bee (Exoneura sp.) White-banded bee (Lasioglossum sp.) Crops Lasioglossum parasphecodes sp. Homalictus sp. Weeds Lipotriches sp. A thicker line connecting a bee to a group of flowers indicates that bee visited that group of flowers more frequently.

Flowering time August Natives September Red reed bee (Exoneura sp.) October Crops November December Reed bees are actively foraging from the end of winter into autumn. Reed bees visit native plants like Acacias and January Hakeas before crops start flowering, and visit native plants like Kunzea, Leptospermum, and Pultenaea after Natives February crops finish flowering in summer and autumn. March

Flowering time August Natives September Lasioglossum parasphecodes sp. Crops October Crops Parasphecodes mostly visits Acacia in November late winter-early spring. Lipotriches mostly visit Kunzea and Natives Leptospermum in late spring-early December summer. January Lipotriches sp. February March

Flowering time August September Crops October White-banded bee (Lasioglossum sp.) Weeds November Crops December Homalictus sp. January White-banded bees and Homalictus mostly visited weeds like cape weed February and wild Brassica that are found in orchards, berry farms, and pastures. March

Landscape associations Landscape types Red reed bee (Exoneura sp.) Black reed bee ? (Exoneura sp.) Heavily forested White-banded bee (Lasioglossum sp.) Lasioglossum parasphecodes sp. Homalictus sp. Mixed forest-agriculture Lipotriches sp. This figure shows the associations of our crop-visiting bees with different kinds of landscapes on the right. In this figure, a thicker line connecting a bee to a landscape type indicates that we found higher numbers of this kind of bee Predominantly agriculture (in our traps and visiting flowers) in that kind of landscape.

Making nests for reed bees

Why reed bees? • Visit all surveyed crops in relatively high numbers. • Carry large amounts of crop pollen (so are probably good crop pollinators… but not yet sure). • Pollinate rarer native plants, including some sun orchids (Thelymitra) and donkey orchids (Diuris). • Artificial nests are easy to make.

Reed bee nests Reed bees usually nest in tree ferns in forests, but sometimes nest in cultivated and wild bramble in landscapes without much forest.

Reed bee nests Reed bees nest in the stumps of old canes cut in previous years (as shown by red arrow in middle picture). They also nest in canes bundled together and housed in PVC pipe (bottom picture).

Thank you Contact me for further information: julian.brown@anu.edu.au This project is supported by AgriFutures Australia, through funding from the Australian Government Department of Agriculture as part of its Rural R&D for Profit program.