Modern-day citizen scientists are following in the footsteps of a well-known Wellington naturalist, collecting moths to document a century of change.

A century ago, Wellington naturalist George Vernon Hudson collected thousands of moths in the bush next to his home, in what is now Zealandia sanctuary.

Now a group of citizen scientists are following in his footsteps, collecting moths to see how the numbers and species of moths have changed over time as the local vegetation has changed.

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For nearly six decades, in the late 1800s and early 1900s, Wellington naturalist George Vernon Hudson walked in the bush next to his Karori home two to three nights a week, collecting moths.

He was a keen observer, finding well-camouflaged moths as they sheltered on tree trunks or on leaves.

He beat bushes with a large stick, using a large upside-down white umbrella to catch moths as they tumbled out.

Back home, he painstakingly prepared the specimens, writing tiny identifying labels that he hid under each moth when he pinned it into a specimen box with its wings carefully arranged.

The details of each specimen were entered into a large ledger, carefully coding what it was, and when and where he'd collected it.

Hudson prepared detailed illustrations of many species, which were as artistically beautiful as they were scientifically accurate.

On his death, the insect collection, illustrations and diaries were gifted to New Zealand's National Museum, now Te Papa Tongarewa.

George Vernon Hudson's life work spans 1881-1946 and is the single largest insect collection in New Zealand.

A century later

A hundred years later, George Vernon Hudson's grandson, entomologist George Gibbs, is one of a group of keen citizen scientists following in the moth collector's footsteps.

The 100 Year Moth Project is an Entomological Society project in association with Zealandia sanctuary, which is a short stone's throw from Hudson's moth haunts.

The team assemble in Zealandia once a month at twilight to set up the light trap, which consists of a bright ultraviolet light, powered by a generator and positioned on a white sheet on the ground.

Moths are attracted to the light and settle around it on the sheet. Half a dozen keen spotters identify different species of moths and collect a few examples of each kind, with most moths being left alone.

Crowd sourcing moth identification

William Brockelsby is the organiser of the 100 Year Moth Project, and he says they collect between 20-50 species in a night. The exact species vary from month to month…

Go to this episode on rnz.co.nz for more details