The back shed. Warm. Rarely used. And slowly being drowned by wasps building a home of their own.

Part-time wasp nest eradicator Kieran Chisnall, of Hawke’s Bay Wasp Control, was this week called out to an Ocean Beach property where he came across the largest nest he had seen.

The shed was tucked away in some overgrown blackberry and grass. In two years of taking on wasp nest jobs in Hawke’s Bay, Chisnall had never seen anything like it.

“When I approached it, I saw the door was partially open and the nest was not just on the outside of the roof part, it was actually behind the door.”

He said nests that he dealt with on a typical job were usually the size of a rugby ball or a basketball at most, but he estimated this nest was about one square metre in size.

“I watch YouTube videos all the time and I have seen some of the world’s biggest wasp nests. I never thought I would see one like that myself doing my wasp control job.”

He said the wasp nest could have been there for over a year or even two years to get that large.

“Normally, in the wintertime, they would die off, but because it was in the shed, where it was warm and sheltered, they just kept building and building, with no frost to kill [them] off.”

Kieran Chisnall estimates that the wasp nest he found in a shed on the Ocean Beach property was one square metre in size, stretching both inside and outside the building. Photo / Kieran Chisnall

Chisnall said he was allergic to wasps, but he decided to start eradicating wasps as a community service as he was a commercial beekeeper and wasps were destructive to beehives.

“On the odd occasion, I have tried to do it without putting the suit on, but I have had a few stings lately.”

He said wasps were usually most prevalent in late summer and autumn, while winter would normally kill them off.

He has had about one or two call-outs per day to take care of wasp nests so far this year.

He said agapanthus, toetoe, flax and old tree stumps were common places to find wasp nests.

“There have been a lot in people’s roofs and walls as well, lately.”

According to the Department of Conservation, the world’s largest recorded wasp nest was discovered at Waimauku, near Auckland, and was 3.75 metres tall and 1.7 metres wide.

According to New Zealand Crown research institute Manaaki Whenua – Landcare Research, about 10 per cent of German wasp nests survive the winter.

Manaaki Whenua – Landcare Research said on its website that while common wasp nests do occasionally survive the winter, overwintering nests found so far in New Zealand had not produced queens in their first autumn.