Ngaire Hart has been looking at the issue as part of her AUT University doctorate.
She says native bee numbers have decreased over the past three years by as much as 60 per cent.
The natives are unlike the introduced honey bee; they do not have hives and do not produce honey but still play a role in pollination.
Ngaire says they are best identified by their nests – a cluster of small holes in the ground.
Not a lot of research has been done on native bees and Ngaire says people need to decide if they are important.
Her study is the first of its kind and has turned out some alarming results.
Nest numbers dropped 61 per cent at Parihaka, 45 per cent at Mt Tiger and 26 per cent on Memorial Drive over three years.
Ngaire says she was surprised by the data, which was consistent across four grids at each site.
She says reasons for the decline could be due to toxins such as pesticides in the environment, disease, loss of habitat or resource competition with other insects.
More research is needed across the country to find out if this is just a natural variation, a seasonal trend or if it is indicative of all native bees, she says.
“One of the big issues of studying native bees is that we need more people to be involved.
“Scientists can’t collect all the data needed.”
Ngaire hopes her methods will enable backyard researchers to collect their own data.
She has a background in radio engineering and used a No 8 wire mentality to collect the samples.
“I used plastic rulers and glued them to make a grid, then took photos of the nests and processed them with an open source medical data package called Fiji,” she says.
“I’d like to see a monitoring programme put in place that involves the public. Monitoring will help raise people’s awareness.”
Christchurch-based entomologist and native bee expert Barry Donovan agrees more research needs to be done to find out if Ngaire has spotted a trend or a one-off variation.
Bee numbers are affected by the success of the bees in the previous summer, so Whangarei’s droughts could have had an impact, he says.
Barry believes the number of native bees overall has increased since before humans came to New Zealand.
The native bees have benefited from deforestation as it gives them more nest sites and they have quickly adapted to introduced flowers.
Since 2000 wild honey bees have been dying due to varroa mite, which means less competition for the native species, he says.
Ngaire would like people to be more aware and more interested in the native bees.
She is also organising an exhibition of her photographs and information, plus drawings and a carving by master carver Stan Wihongi to help raise awareness.
The exhibition is on display at AUT in central Auckland but she hopes it can taken to galleries and schools next year.
“To me it’s quite important to share the information outside the academic community. It’s our natural history and it’s knowledge that belongs to everyone.”
- Adopt A Hive (adoptahive.wordpress.com)