Cytotaxonomy ofCalliphoridae (Diptera)

Abstract

A modification of the general system of classification of Calliphoridae is proposed in this report. Information about the chromosome complements of about 90 species is provided including references to the earlier literature on chromosomes of this family. With one exception all species studied by us or by earlier investigators have 2n = 12. The total complement length of 556 complements from 83 species averaged 66.4/x. Most species have a short heteromorphic sex pair but the size and morphology vary considerably and one species, HemipyreUia fernandica, seems to have a quadrivalent sex-chromosome complex in a 2n = 14 complement. The autosomal pairs vary in both length and arm ratios between the species but seem to be more stable than the sex chromosomes. Only minor variations were found between different collections of the same species except for two collections of Calliphora croceipalpis. Although presently available data on the chromosomes of Diptera species suggest that increases in total complement length accompany evolutionary progress, no such general trends were obvious in either the total complement lengths or chromosome morphology, either within or between the tribes of Calliphoridae. Thus the karyotypical reorganizations in the family have apparently not been directly associated with changes in the general morphological features of the adults which may have responded in these respects more extensively to genetic mutations.

C-banding and FISH in chromosomes of the blow flies Chrysomya megacephala and Chrysomya putoria (Diptera, Calliphoridae)

“…The gross morphology observed here was more similar to that reported by Boyes and Shewell (1975) for a population from Johannesburg, in which all the autosomes were metacentric, than to that of other authors (Üllerich 1976, Azeredo-Spin & Pavan 1983.…”

“…Thus, comparison of our data on chromosomal morphology with those of Boyes and Shewell (1975) and Üllerich (1976) and with the C-banding pattern provided by Üllerich (1976), together with more recent studies, indicated that the species introduced into Brazil was C. putoria.…”

“…Boyes and Shewell (1975) reported no such constriction, whereas Üllerich (1976) observed secondary constrictions in chromosomes II and III of both C. putoria and C.…”

“…However, subse-quent crossing experiments showed that these flies were at least partly genetically isolated and merited species status (Zumpt 1975). Boyes and Shewell (1975) and Üllerich (1976) considered these species to be distinct based on their cytogenetic characteristics, and this is the currently accepted view.…”

“…Based mainly on this similarity, Zumpt (1956) concluded that these flies were subspecies rather than species, although this author subsequently accepted them as separate species (Zumpt 1965). Boyes and Shewell (1975) and Üllerich (1976) also considered these flies to be distinct species based on a cytogenetic analysis.…”