Scientists in Wellington believe they have discovered a world first in wetas.

A 24-hour search of Otari-Wilton's Bush reserve in Wellington has uncovered 1,345 new species of animals, plants and bacteria.

The bioblitz, which has previously been held in Auckland, involved 80 scientists and wrapped up yesterday afternoon.

Bioblitz science director, Professor Phil Garnock-Jones, says the biggest discovery is a new species of cave weta.

He says once scientific tests prove the weta is of a new genus or family those who discovered it will have to find a name for it.