Category: Invertebrates

Artystona rugiceps

This flightless beetle is a bit under 10 mm long and is quite common on Puangiangi. It’s seen on tree trunks after dark, where it feeds on lichens. Ian Millar and John Marris (Lincoln University) placed it in Artystona, which is endemic to New Zealand.

The species designation is likely but not certain- it’s pretty difficult to get a full identification from a few photos. What’s important is getting an overall impression of the invertebrate fauna on the island and to see if that informs us about ecosystem health and whether it is typical of what we should see in the region.

These beetles are Tenebrionids or darkling beetles, named because they are nocturnal. All told there are about 150 species of darkling beetles in New Zealand. This is one of the smaller ones on Puangiangi. A. rugiceps is the species most frequently reported on iNaturalist and is found throughout the country.

Somatidia sp.

I was struck by the beautiful colourings of this small beetle (about 4-8 mm from memory- I didn’t get a size-calibrated picture). Philip Howe and James Tweed placed it in Somatidia.

Literature I can understand is a bit hard to find, but it looks like there are four species endemic to New Zealand and quite a few more in Australia, Oceania and South-East Asia. Please correct me on this point!

These photos are all of the same individual. Note the tiny mite near its top right eye- passenger or parasite I don’t know.