An international beetle specialist said the bug commonly known as the Mount Mauler might not be responsible for causing itchy bites on humans.
Scientist and beetle specialist Richard Leschen from Landcare Research told the Bay of Plenty Times there was no evidence the beach bug, scientifically named phycosecis limbata, had ever bitten a person.
"I'm not convinced they bite anyone," he said. "I've collected them and researched them and I have never been bitten in my life.
"In saying that I'm not a doctor or a pharmacist, I'm a beetle specialist and I study beetles all around the world ... what I'm saying is that there needs to be evidence of these things biting people before we can say that they do."
Mr Leschen said very little was known about the life-cycle of phycosecis limbata beach bugs but the family which they came from had been thoroughly researched.
Mr Leschen said the lifecycle began when a female laid an egg, which developed into larvae. It would then pupate, similar to a moth or butterfly, then emerge as an adult beetle.
The bugs lived on coastal beaches all around the country, were more active during the day and fed on debris and decaying animal matter, including carrion.
Mr Leschen said they were very tiny and had small mouths: "and whether they can pierce skin on the human body is yet to be determined".
"I don't know what's going on with the things that are biting people but I suspect it could be something else."
He suggested beach flies or other insects could be responsible for biting beachgoers.
But Amcal Mount Dispensary pharmacist Mark Bedford believes the same bug, phycosecis limbata, nibbles on people along the Western Bay coastline.
He has been researching the bug for the past 14 years and said the bugs were "in full season" between November and February, when lots of people were at the beach.