Cosymbiini

There appear to be no really satisfactory adult characters on which to define this tribe but the two major groupings within it, the genus ChrysocraspedaSwinhoe and the Cyclophora Hübner group of genera, share the remarkable characteristic of a pupal girdle, otherwise known in the butterflies and the Hedyloidea (Common, 1986; Holloway, Bradley & Carter, 1987; Bigger, 1988; Scoble, 1986, 1992). There is also an observation of this in the larentiine genus Sauris Guenée, but this needs confirmation. In the butterflies it is thoracic, in the Hedyloidea it traverses the first abdominal segment, and in the Cosymbiini it traverses the third. In the Timandrini and Rhodometrini, the putative sister-groups (See Sterrhinae), the pupa is suspended in a web or in a loose cocoon. The pupa itself is anteriorly truncate, square-shouldered, with a cluster of eight equal hooklets terminally on the cremaster. (see Nakamura (1994); Patocka (1994a), and accounts of individual genera and species following).

In the male abdomen, sternite 2 can be marginally thickened (Chrysocraspeda) but it is never setose. When the hind-legs are modified with scale tufts in the Cyclophora complex, these tend to be associated with coremata more distally on the abdomen, usually the fourth sternite.

The female genitalia show definitive features for various genera, but no tribal characteristic has been located. The bursa copulatrix tends to be rugose throughout, but this rugosity is sometimes strengthened into paired signa (Chrysocraspeda) or a longitudinal ridge (Cyclophora), or becomes more distinctly spined (Cyclophora subgenus Streptopteron).

The tribe is found throughout the world except for more remote islands, including New Zealand, and at very high latitudes.

Its nomenclature presents some problems as discussed by Holloway (1993 [4]). Cyclophoridae and Cyclophoroidea are used extensively and frequently as higher categories by prosobranch malacologists (Dr P.B. Mordan, pers. comm.), therefore it would be in the interests of stability to yield to them should there be any dispute about priority. The most frequently used alternative is Cosymbiini, though Zonosomini has claims to priority (Holloway, 1993[4]). Both CosymbiaHübner and Zonosoma Lederer are junior synonyms of Cyclophora.