Intrigued by beetles
RECENTLY, in hot sunshine on Swampy Spur, near the top of the Northern Motorway, I observed a strikingly coloured beetle, 13mm long, climb on to a treefern stump beside a forest track. Two others, identical, walked up beside it. These were
Ctenoplectron vittatum, of the family Melandryidae.
When 9 years old, I found a single wingcase of this beetle on one of the many old treetrunks piled in a gully on a big inland Taranaki sheep station at Ararata. The pattern on the wing case — dark purpleblack, with a long thin lengthways orange band and a brightyellow transverse band below it — looked more like the work of a commercial artist than a product of nature, and I longed to see the entire beetle. It was many years before that wish was fulfilled. The beetle seen today had wing cases in no way different from that found at Ararata — the beetle’s coloration seemingly remains constant throughout New Zealand. Beetles in the family Melandryidae are very active on foliage in midsummer and, using their legs, jump with great agility.
As I continued to watch, several striking beetles with very sharply pointed abdomens jumped from tree leaves above on to a piece of white lacy fabric. Measuring 9mm long, these were Stenomordellaria neglecta, of the family Mordellidae.
The great amateur New Zealand entomologist George V. Hudson wrote in 1934 that S.
neglecta is attracted in large numbers to the flowers of white manuka and white rata, between January and March. Mordella
antarctica, which looks similar, but is much larger, can reach 17mm in length, behaves in a similar way.
To these beetles, white fabric may look like white flowers when viewed through the leaves of the trees above.
It is currently the height of the season for the adult stage of most insects and this is the time eagerly awaited by entomologists.