An adult bedbug in a handout photo.

Auckland - Bedbugs are back - experts say a plague is affecting hotels, apartments and student housing.

Exterminators are doubling their work and hotel staff are being trained to spot the pests.

New Zealand's popularity with backpackers and tourists is partly to blame, but experts say poor hygiene is not necessarily to blame for their arrival.

Motel Association chief executive Michael Baines said hotel staff were being trained to search for the bloodsucking pests, which have also become a problem in New York and some parts of Europe.

“We have some fairly significant training programmes that we go through to make sure motels are aware what bedbugs are,” he said.

“We've even gone so far as to take dead bedbugs around New Zealand so they can identify them.”

Technical support manager for the pest control company Kiwicare, David Brittain, said bedbug problems were increasing around the world, and New Zealand had been hard hit because of its popularity with backpackers.

“Increased travel is a cause because the bugs don't fly and they don't travel far from their host's living space.

“The thing about bedbugs is they will find anywhere, usually within 5m of the bed, which usually means the bedroom or adjacent rooms.”

Brittain also blamed the increase in second-hand furniture exchanges and the resistance bugs had developed to weak insecticides.

He said Kiwicare had sold more than 20,000 bedbug products in the past year, double its expectation.

Poor hygiene was rarely associated with an infestation - the bugs were found in expensive hotels and upmarket apartments.

Mr Brittain recommended a combination of pesticides, vacuuming, heat treatment and plastic wrappings that suffocate the bugs to fully eliminate bedbugs and their eggs.

Eric Van Essen, technical director of Ecolab, which provides cleaning services to the hospitality industry, said the insect did “not discriminate between five-star accommodation and backpackers accommodation”.

“If you don't eradicate the problem by getting rid of every last bedbug - as in very, very thorough searching of all of their harbourages and not underestimating how small a crack or crevice they can hide in - then there's the risk that it's just going to keep on becoming a problem,” he said.

The Auckland Council said it was hard to determine the number of yearly bedbug complaints since it was mainly the individual responsibility of the accommodation providers. - The New Zealand Herald