Australian Native Bee Library
Megachile species
Pronunciation: megga-kye-lee
There are about 150 species of Megachile distributed throughout Australia, made up of two groups: leafcutter bee and resin bees.
Identifying characteristics include large jaws and females have long, bristled scopal hairs under the abdomen. About 20 per cent of male Megachile have modified forelegs, which contain pheromone secreting glands, to entice female suitors.
Taxonomy
Megachile species
Family
Megachilidae
Genus
Megachile
Foraging behaviour
Most Megachile are generalist foragers and will visit a range of flowers to collect pollen and nectar. However, they particularly preference native pea flowers, in the family Fabaceae, and are very effective pollinators of these plants.
Nesting behaviour
Megachile generally nest in pre-existing cavities such as old borer holes, under bark, knot holes or hollow stems. Some, such as Megachile maculariformis, can also dig shallow burrows in soil.
Megachile use their large jaws to collect nesting material to line and seal each brood cell. Leafcutter bees use precisely cut segments of soft, young leaves. While resin bees collect plant resins to line the nest and add small stones or chewed leaf to the resin mix, when sealing the nest entrance.
Providing nesting space for native bees
Well–designed bee hotels can be particularly useful in providing nesting substrate for Megachile species.
Leafcutter and resin bees vary in size from 8mm to 16mm in length, so bee hotels should include a variety of burrow diameters, to cater for large and small bees. When choosing hollow stems or drilling burrows in hardwood blocks, holes should be between 3mm and 8mm in diameter. The burrow depth should be as deep as possible, but with a blind end, to allow females to produce a healthy ratio of male to female offspring. It also reduces the proportion of brood cells that may be parasitised by flies or wasps.
Fun Facts
The name Megachile stems from the Greek words; ‘megas’ meaning large and ‘cheilos’ meaning lips or mouth.
A female leafcutter bee will cut oval shapes to create the walls of a brood cell. She then provisions the cell and lays an egg on top. This is followed by her cutting a circular shaped piece of leaf to seal the opening to the brood cell.
Leafcutter bees usually alight on a flower with their wings spread, whereas resin bees usually close their wings over the abdomen.
With written contribution from Megan Halcroft