Insect collection
Flower visitors were sampled for five days each month in 2008 using
flight intercept and pan traps (Howlett et al. 2009). Insect
traps were placed at the centre of the focal field. At each site, two
yellow flight intercept pan traps were positioned 2 m apart on stakes at
a height of 1.2 m. Each trap consisted of a pan measuring 22 cm x 35 cm
x 6 cm attached to two vertical panes (flight intercept) that were
arranged perpendicular to each other. To facilitate pollen collection on
insects, we lined the traps with clear acetate sheets 22 cm x 30 cm and
tangle foot paste (The Tanglefoot Company, Grand Rapids, MI, USA).
Tanglefoot was applied as a thin film to the surface of the acetate
sheet to maximise insect capture while preventing loss of pollen to
excess drops of Tanglefoot. The acetate sheets with trapped insects were
replaced daily. Insects were sorted into orders and those carrying
pollen were then pinned and identified to family-level by experts, using
appropriate keys (CSIRO 2018a, b; Marshall 2017).