Coelostomidiidae

Foldi, Imre, 2009, Archaeococcoid scale insects (Hemiptera: Coccoidea) from the tropical high mountains of the Andean Cordillera, South America, Zootaxa 2300, pp. 1-38 : 25-26

Family Coelostomidiidae

The Coelostomidiidae is a small family including species characterised by large morphological variations (particularly in the antennae, legs, cicatrices and anal tube) in successive instars and in their behaviour, i.e. adult females are free-living or retained within the preadult exuviae and tests (see below). Currently, species of this family only are known from Mexico and the Neotropical and New Zealand regions. The subfamily Coelostomidiinae was established by Morrison (1927) in the family Margarodidae , and elevated to family level by Koteja (1974). The family-level status of this group was accepted by Hodgson & Foldi (2006) and Gullan & Cook (2007). The New Zealand coelostomidiids, Coelostomidia Cockerell and Ultracoelostoma Cockerell , were revised and well illustrated by Morales (1991). As regards the status of the family, it seems likely to be monophyletic based on the morphology of adult males ( Hodgson & Foldi, 2005) and adult females and nymphs ( Morrison, 1928).

Most adult female coelostomidiids are « pupillarial » forms, i.e, the adult females are retained and oviposit within the strongly sclerotised exuviae of the preceding preadult female stage (i.e., in the genera Cryptokermes Hempel , Mimosicerya Cockerell , Paracoelostoma Morrison , and Ultracoelostoma Cockerell ), whereas adult females of Coelostomidia Cockerell and Neocoelostoma Hempel are not pupillarial, possess well-developed legs and leave the exuviae of the preadult to oviposit. The adult females of Cryptokermes and Mimosicerya have a large, sclerotised zone on the head, which extends onto the thorax; an identical sclerotised zone is also present on Stigmacoccus sp. (Stigmacoccidae). In contrast, the adult female of the genus Paracoelostoma lacks a sclerotised zone on the head but the anal area becomes slightly sclerotised at maturity. Adult females of the genera Coelostomidia , Neocoelostoma and Ultracoelostoma lack a sclerotised zone on both head and anal area. In addition, the immature instars of most species secrete a white wax tube from the margins of their anus, which serves to carry the liquid excreta away from the body.

Adult females of Coelostomidiidae are characterised by the following features: the mobile adult females of Coelostomidia and Neocoelostoma have abundant hairs, hair-like setae and flagellate setae, abundant multilocular pores, and well-developed legs and antennae. The adult females of species that remain within the preadult exuviae ( Cryptokermes , Mimosicerya , Paracoelostoma and Ultracoelostoma ) have fewer setae, spines and pores and the legs and antennae are reduced. Mouthparts are present or greatly reduced or absent; the atria of the thoracic spiracles are without pores but each spiracle has a cluster of multilocular pores outside near peritreme; each spiracle also has an apodeme; there are 7 pairs of abdominal spiracles, and the most? posterior pairs may be smaller than the others; the atria of which spiracles? have multilocular pores; cicatrices are present in nymphal instars and usually absent on adult females, except that small cicatrices may be present on the ventral head region of the adult female, as in Coelostomidia montana Green ( Morales, 1991) . The anal opening is usually apical; the anal tube is rather membranous with or without a sclerotised ring at the inner end.