Margarodidae (Insecta: Hemiptera).
The endemic New Zealand coccoid genera Coelostomidia, Platycoelostoma and Ultracoelostoma are revised. Four new species (including C. jenniferae sp. nov. and U. brittini sp. nov.) are described. The immature female life stages of all 10 species (which include C. wairoensis, C. zealandica, U. assimile and P. compressa) and the male stages of 5 are described and illustrated. The adult females and 1st instars of the 2 introduced taxa, Icerya purchasi and I. seychellarum, are described. Keys are given to all life stages of the endemic genera. The life histories of C. wairoensis and U. brittini are described and illustrated. Brief summaries are given of the classification of the Margarodidae, their economic importance, biology, life history, host-plant associations and collecting and mounting techniques. Work on the group in New Zealand is reviewed.