Scale insects (Hemiptera: Sternorrhyncha)
Scale insects are sap-sucking bugs in the superfamily Coccoidea: a group of insects comprised of about 7500 species worldwide but much smaller in New Zealand with less than 400 species.
The whiteflies (Aleyrodidae), with 16 species in New Zealand, are a sister group in the suborder Sternorrhyncha and have a similar life habit. They spend most or all of their lives feeding on plants, and adventive species are primarily important as plant pests on crops and fruit trees. Endemic species are generally not of economic importance except the sooty beech scales (Coelostomidiidae) that are beneficial in forest ecology and apiculture for their production of honeydew. Scale insects vary dramatically in their appearance from very small organisms (1-2 mm) that live under wax covers (some look like oyster shells), to larger creatures (5-10 mm) covered with mealy wax and that can walk around, and often produce their eggs in large ovisacs.
Each of the scale-insect families present in New Zealand varies widely in its number of genera and species and its proportion of endemicity. There is just one endemic family, the rather mealybug-like Phenacoleachiidae, with two described species. In contrast, Halimococcidae with one species and Ortheziidae with three species have no New Zealand endemics. Asterolecaniidae and Cerococcidae have about six and two species respectively, mostly endemic. The soft scales (Coccidae) have high endemicity with 45 of a total 59 species and 11 of a total of 17 genera found nowhere else in the world. Mealybugs (Pseudococcidae) and armoured scales (Diaspididae) are characterised by a smaller proportion of endemic genera and species, while the felt scales (Eriococcidae) are hugely endemic at the species level with only five adventive species, mostly shared with Australia, out of a total 104 species. Also, felt scales have twice as many endemic taxa as adventives at the generic level. Some strange effects of New Zealand's volatile geological past are seen in the scale insect fauna, for instance, unexplained extinctions like the complete absence of armoured scales on Nothofagus, coupled with a strong radiation of felt scales on Nothofagus.
Current research is focused on two families. Firstly, the taxonomy of the Eriococcidae with additions to the known fauna from cryptic habitats, and a revision of the Nothofagus feeding clade. Secondly, a complete revision of the Diaspididae in two parts for contributions to the Fauna of New Zealand series. One part is intended to cover all of the adventive species and the indigenous non-Leucaspidine species. The other part will endeavour, with the aid of molecular information, to capture species distinctions in the radiating tribe Leucaspidini.
20 December 2012. It is with deep regret our invertebrate systematics group records that Rosa Henderson unexpectedly passed away on 13 December 2012. Enquiries concerning Sternorrhyncha should be directed to the NZAC Head Curator, Dr Robert Hoare.