Scalloped cut-outs on summer foliage are a sure sign that a leaf-cutter bee has been at work gathering materials for its nest. But this does not harm the plant and there is good reason to encourage these resourceful insects into the garden
THE ROSES ARE in full bloom; their perfume sweet and heavy in the air. Bees and other insects buzz from flower to flower, feasting on the nectar. But on the branches below, a small and slightly hairy bee perches on the edge of a leaf. Following a smooth curve, she cuts a ½in (13mm) wide semicircle out of the rose leaf with her jaws, then bends her head to tuck the piece back under her body.
With the leaf section grasped firmly between her rear legs, she takes flight, looking as if she is surfing through the air on a miniature green frisbee.
This is a female Patchwork Leaf-cutter bee, Megachile centuncularis, the most common of seven species of leaf-cutter bees found in the UK. They live in gardens and parks, as well as in rural hedgerows and farmland, and are widespread across the country, although local populations are typically smaller in northern England and Scotland.
Similar in size and shape to a honeybee, the Patchwork Leaf-cutter has a dark brown body, approximately ½in (13mm) long, overlaid with short, golden-brown hairs. The females also have an eye-catching orange pollen ‘brush’, called a scopa, on the underside of their abdomen. The males lack this, but have dense white hairs on their front legs, giving the appearance of wearing fuzzy mittens.
No harm done
The main sign of leaf-cutter bees within the garden is leaves with a neat scalloped pattern of uniform semicircles cut out along the edges. These scallops are much larger and more regular than the small notches left by Vine weevils. As well as rose bushes, leaf-cutter bees will cut from a range of trees and shrubs, including lilac, honeysuckle, wisteria, beech, birch and horse chestnuts. While it is noticeable, the small amount of leaf removed is not enough to harm the plant.
The leaf-cutting occurs from early summer to autumn as the female bees use the leaf sections to build their nests. These are made in narrow, 4-6in (10-15cm) long tunnels within hollow stems or soft wood. While some species make fresh tunnels, the Patchwork Leaf-cutter bee generally prefers to use pre-existing ones. The nests are built as a series of thimble-shaped cells along the tunnel, working towards the entrance. Each ‘cell’ is made of overlapping cut-leaf sections, glued together by saliva. The female bee then fills the cell with nectar and pollen to provide a food source, before laying a fertilised egg and capping off the top of the cell with further leaf sections. The earliest cells, deepest in the tu
