A northern hemisphere bee species is spreading through New Zealand and its males will aggressively attack other insects visiting flowers in their territory.
Wanganui woman Lynne Douglas has been an insect hunter all her life, she says, and noticed the odd-looking bright yellow bees hovering over flowers in her Castlecliff garden. The insects were about the size of honey bees, but looked different.
They have since been identified as wool-carder bees, which are native to Europe, North Africa and Asia but spreading rapidly through North and South America and now New Zealand.
Mrs Douglas tracked down Auckland University student Jo-Anne Soper, who studied their spread in New Zealand for the thesis she finished in 2011. She said Mrs Douglas's Wanganui sighting was the first for the area.
The bees are called wool-carder because the females collect hair from fuzzy plants and use it to build their nests in cracks and crannies.
Their scientific name is Anthidium manicatum and they are related to leaf-cutter bees and mason bees.
Males are larger than females, and aggressively territorial. They hover over their territories and attack other insects that come to flowers there - especially honeybees, bumblebees and other male wool-carders that want to mate with the females there.
Males have five spines on the rear of their abdomens, and can use them to kill or drive off other insects.
The female bees will also hover over flowers, but they are not aggressive.
Wool-carder bees are commonly seen from November to April, and are usually dormant during winter. They don't live in colonies. Instead, individual females lay two or three batches of eggs in their nests each season.
Being northern hemisphere bees, they have a preference for northern hemisphere flowers like rosemary, salvia and foxgloves. They feed on pollen and especially like blue or purple flowers.
Ms Soper was interested in the impact of the new species on the New Zealand environment. It was spreading fast from where it was first seen in Nelson, Napier and Auckland in 2006-2008.
But its impact may not be major, she said, because the bees seldom attack this country's native bees and they like only a limited range of plants.
Ms Soper is still interested in sightings of them, and can be emailed at jo-soper@ihug.co.nz
Nature Watch
Nature Watch is a Wednesday feature for the Wanganui Chronicle's outdoor section. It aims to note the sights, sounds, smells and tastes of the region, through its plants and animals, as the seasons pass.
Do you have a favourite sight, sound or smell of autumn? Tell me about it. Ring 06 349 0710 ext 50833, email laurel.stowell@wanganuichronicle.co.nz or write to Laurel Stowell, Wanganui Chronicle, PO Box 433, Wanganui.