Coelostomidiidae

Common name

Coelostomidiids

Field characters

Body usually globular, frequently occurring in thick test; white tube usually protruding from posterior apex of test; most instars with reduced cone-shaped legs, but Coelostomidia and Mimosicerya with fully developed legs.

Validation characters

Anal tube usually apical, with internal sclerotized ring and pores, rarely simple and without ring and pores; usually with 7 pairs of abdominal spiracles, rarely 6, posterior pair sometimes smaller than others; legs either fully developed or reduced and cone shaped; when cone shaped, with claw present; thoracic spiracles with bar, without pores in atrium, with cluster of pores outside of atrium; often with large sclerotized area surrounding anal opening or on head.

Notes

This subfamily is highly variable morphologically but seems to form a discrete group of 5 genera. Coelostomidiidae Morrison was first used as a family by Koteja (1974).

Distribution

Coelostomidiids occur in New Zealand, Mexico, and Central and South America.

Hosts

Coelostomidiids occur on a wide array of hosts, but generally are found on trees or shrubs.

Life history

Coelostomidiids have 4 instars in the female and 5 in the male. The biology of some New Zealand species has been studied in detail. An example of a typical coelostomidiid life cycle is of Ultracoelostoma assimile: Crawlers emerge from the test through the anal tube exit hole; they settle in crevices on the bark, begin feeding, develop the anal wax tube, and become enveloped in a fluffy wax covering that eventually hardens. The remaining 3 instars reside in the test and the shed skins of each are pushed to the posterior end of the test. Second and third instars have reduced conical legs and continue to feed and enlarge the test. Adult females have reduced mouthparts and do not feed. Eggs are laid as the female shrivels and eventually fill the test. The first two instars of the male are identical to those of the female. The third instar is the prepupa and it apparently emerges from the test through the anal tube exit hole. This instar is quite active and moves to the base of the host tree. The fourth instar is the pupa and it molts to the adult inside a white fluffy cocoon.

Important references

Gullan and Sjaarda 2001; Hodgson and Foldi 2006; Morales 1990; Morales Hill and Walker 1988; Morrison 1928.

Diversity

Click here for a check list of all coelostomidiid genera and species.