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A revised taxonomic and geographical inventory of world blackflies (Diptera : Simuliidae)

Roger W. Crosskey and Theresa M. Howard

Taxonomic information

Scope

The Inventory covers nominal taxa of blackflies known to us to have been described up to 1 November 2003. Fossil taxa are included if they are unequivocally Simuliidae and their palaeontological status is highlighted by enclosure of the entries in square brackets; the geological period is included as part of the provenance data. The following fossils that have been associated with Simuliidae are excluded on grounds that their assignment to the family is clearly erroneous: Liauningius robustus (Hong, 1982) (Chironomidae), Mesasimulium lahaigouense Zhang, 1986 (family uncertain), Pseudosimulium humidum (Westwood in Brodie, 1845) (family uncertain), Simulia pasithea Heyden, 1870 (? Ceratopogonidae), Simulia terribilis Förster, 1891 (? Ceratopogonidae), Simulidium priscum Westwood, 1854 (Anisopodidae), Simulium ? ventricum Lin, Yao, Xiang & Xia, 1988 (family uncertain). Vernacularly named taxa, ie those that can be found at least partially described in the literature (if only in keys) and are known only by letters, numbers, place names, chromosomal diagnostic features etc, are included in their appropriate positions. However, the simuliid literature is enormous and we do not guarantee that every vernacular 'handle' has been unearthed.

Subspecies and complexes

The subspecies category has not been widely used in the Simuliidae and when it has the concept has usually borne little relation to the 'Mayrian' geographically based concept of a subspecies. Its main use has been in various works on the Palaearctic fauna by I.A. Rubtsov and summarised in Rubtsov & Yankovsky (1988). However, Yankovsky (1995) has since ceased to recognise these Rubtsovian subspecies as having separate validity and has disposed of most of them as straight synonyms. In the Inventory we list no subspecies as such but indicate where names are still sometimes applied to subspecies by a few authors in contemporary literature by suffixing the names with '(ssp.)' where they are listed in the appropriate species entry. It is now long established that some apparently single species (morphospecies) are complexes of biologically separate sibling species, these usually defined on chromosomal criteria and conveniently called cytospecies. Where a morphospecies is known to be such an aggregate of sibling species the suffix '(complex)' has been given immediately following the valid species/author/date statement. In many such complexes the precise status of the constituents is often undetermined (ie they are not necessarily always of definite specific status) and they still lack formal scientific nomenclature. To deal with this situation we have suffixed each such name based on chromosomal characterisation with the inert term '(cytoform)': this is to be read as a non-committal umbrella for entities both of undetermined status (cytotypes) and of more or less completely definite sibling status (cytospecies). (The equivalent 'morphoform' has been used for entities based on hard-parts morphology but still only informally named.)

Inventory format

Scientific (Latinised) names entering into formal nomenclature are ranged to the left-hand margin if valid, but indented if they are synonyms. Valid names are alphabetical but synonyms are in chronological order to show their relative priorities. Vernacular 'names' are similarly ranged left if on current knowledge they could pertain to valid species but are indented if they are synonyms. Vernacularly named entities are listed at the end of the appropriate entry, after the scientific names. Taxonomic rank and validity or invalidity of names are distinguished by lettering style: generic and subgeneric names are in capitals (bold type when valid and lightface italics when synonyms), and specific names in lower case letters (bold type when valid and lightface italics when synonyms). In species-group headings the specific epithet is highlighted by the use of capitals, eg 'ORNATUM species-group'. In the very rare situation where a species appears to be 'good' but its name is at present technically invalid that name is ranged left and printed in lightface italics to show that it cannot be validly used; see below under 'Homonyms' where such cases refer to specific names that are unreplaced homonyms.

Nomenclature

Spellings, authorship, dating, availability status, and other relevant aspects accord with the requirements of the current (fourth) edition of the International Code of Zoological Nomenclature published in 1999 and effective from 1 January 2000. It is noted particularly that, in accordance with articles 31.2 and 34.2, the spellings of specific names conform to the gender of the generic names with which they are combined; the gender of the subgenus (if any) is not relevant.

Nomenclatural annotations. Appropriate annotations are given when necessary, for instance when a name as published is unavailable (eg a nomen nudum or proposed for a variety or form after 1960) or was published as a replacement name for a preoccupied (junior) homonym, or the name has the technical status of an incorrect original or incorrect subsequent spelling (the latter limited to misspellings of some consistency or importance). Where a name has been the subject of an official Opinion of the International Commission on Zoological Nomenclature the Opinion number is given accompanied where relevant by the word 'List' or 'Index', the former referring to the Official List of Specific Names in Zoology and the latter to the Official Index of Rejected and Invalid Names in Zoology. (There is one instance of 'Gen. List' (ie Cnetha), this referring to the Official List of Generic Names in Zoology.)

Homonyms. It is necessary to call attention to a terminological change for names used to replace preoccupied names (homonyms). When the 1997 Inventory was published these names, following the provisions of the then current third edition of the International Code of Zoological Nomenclature, were termed 'replacement names' or (if not in fact needed) 'unjustified replacement names'. Regrettably, a wholly unnecessary change has been made in the fourth edition of the Code whereby replacement names (unless being published for the first time) are called 'substitute names' and those already made but not required are called 'unnecessary substitute names'. The appropriate change has been made in order to conform to the current Code, and the abbreviation 'subst.' will be found in place of 'repl.'.

Type species. The type species is shown that applies for each generic and subgeneric name (whether valid or in synonymy) and its mode of fixation stated. The authors of names of the type species are omitted since these are provided in the appropriate species entry. If the nominal type species is not now valid the present senior synonym is shown in addition, eg 'HELLICHIA Enderlein, 1925 (as genus). Type species: macropyga, as latifrons' indicates that latifrons was the cited type species when Hellichia was established but is now a junior synonym of macropyga.

Changed combinations. The author's name and year date of description are enclosed in parentheses (round brackets) whenever the species concerned is no longer in its original genus, ie when the current binomen (combination) differs from that of the original publication. This is to accord with Code Article 51.3. A point worth stressing here, since errors are still occurring in the simuliid literature, is that transfer of a species from one subgenus to another without change of generic assignment does not constitute a new combination in the meaning of the Code.

Dates. The year date applicable to a zoological name is that on which the publication containing it was issued (distributed). This date usually agrees with that stated on or in the publication, but in many cases the date is later than (or even precedes) the stated date on the title page of the book or periodical part. When the actual date of issue can be found somewhere inside the publication (or in a list of issue dates specifically provided) but differs from the nominal date the two dates are given in the form '1934 [1933]'; when the actual date of issue has been determined from outside the publication (eg from information provided by a publisher) the two dates are given in the form '[1988] [1987]'. In both cases the first date given is the correct one under the Code and should be cited for the taxon concerned. See Code recommendation 22A.2.3 relating to mode of citation.

Specific names involving '-cola'. There are several of these in the Simuliidae and there has been confusion concerning them. The suffix '-cola' is a noun in classical Latin (eg see Stearn, 1995) but the New Latin adjectival derivatives '-colus' (masculine), ' -cola' (feminine) and '-colum' (neuter)' have a long pedigree in zoology and their use in nomenclature has never been prohibited by the International Commission on Zoological Nomenclature. The spelling is not subject to alteration where it was clearly originally used as a noun, eg Simulium monticola Friederichs (mountain-dweller, use of -cola with neuter generic name) but is subject to gender change when used as an adjective, eg Eusimulium alticolum Dyar & Shannon (dwelling high, spelling showing use as adjective in combination with neuter generic name). Thus in the latter case the original spelling alticolum is subject to mandatory change to alticola when combined with Cnephia or Mayacnephia (both feminine). See also Brown (1956: 48).

Varieties and forms described after 1960. Under the International Code of Zoological Nomenclature (Article 45.6) a name published for a 'variety' or 'form' after 1960 has no status in zoological nomenclature. It lies outside the provisions of the Code, is unavailable and thus not a nominal taxon based upon type specimens. Such a name can become available by the action of the original author or some other later author if the entity is later treated as a subspecies or species (when it would enter into the purview of the Code). Not all authors publishing on Simuliidae since 1960 have noticed or observed this aspect of the Code and there are some names to be accounted for that come into this category. These are suitably annotated in the text. Fourteen of the names concerned (the majority) were published by Rubtsov for 'varieties' in 1962-1964 but only two of these have subsequently been made available. The others remain unavailable, though Yankovsky (1995) has listed them as if they are available nominal taxa and has cited for them 'holotypes' or 'lectotypes'. In fact, since the names are still unavailable (and likely to remain so) these putative primary types have no status as types. Rubtsov & Yankovsky (1988) listed the 'var.' names concerned as trinomials but did not state that they intended by this to 'promote' the entities to subspecies rank and Yankovsky (1995) has since disregarded the varietal names as mere synonyms of the species names concerned. The listing in trinomial form by Rubtsov & Yankovsky (1988) therefore did not confer availability upon them.

Misidentifications

The history of simuliid taxonomy is marked by an enormous amount of misidentification, not because of the incompetence of its practitioners but because of the extraordinary similarity of many species, especially when their early stages are still unknown - and sometimes even when they are known. Much of this was long ago and it would be unrealistic and pointless (even if it was practicable) to attempt to capture every instance which bedevils the literature. Some misidentifications, however, have been serious and/or long persistent and still have some continuing potential for misunderstanding. We have entered misidentifications, even if quite old, when their entry appears to us warranted in the interests of clarification. The included misidentifications are enclosed in square brackets and are given in the general form '[hirtipes: authors, not Meigen]' when the error occurs rather generally in the literature but in the more precise form '[exiguum: Dalmat, 1955, not Roubaud]' when the error pertains to, or originated in, an influential work of a certain date by a particular author. Where the misidentification involves important literature for a particular area this is indicated by an appropriate addition, eg ['mutata: Japanese authors, not Malloch]'.

Authors' names

A few authors published under variant versions of their names. We have standardised as follows: Baranov (not Baranoff); Ramírez-Pérez (not Ramirez Perez, Ramírez Pérez); Rubtsov (not Rubtzov, Rubzov, Rubzow); Zivkovitch (not Zivkovic). For 'De' versus 'de' we have standardised to 'De' even if an author has occasionally used the lower case variant, hence for example De Meillon, De León. It proved impracticable, within the restraints of the format, to distinguish in a neat and uncluttered fashion between authors who happen to share the same surname, eg the Canadian specialist D.M. Davies and the British specialist L. Davies. Consequently, in common with usual catalogue and checklist procedure, the initials of 'duplicated' authors are omitted. (In practice the author(s) and year date given for any name will be sufficient to trace the original reference through the Zoological Record.)

28-Jun-2004 Dr B R Pitkin