FORUM Classification of Mosquitoes in Tribe Aedini (Diptera: Culicidae): Paraphylyphobia, and Classification Versus Cladistic Analysis HARRY M. SAVAGE Centers for Disease Control and Prevention, P.O. Box 2087, Fort Collins, CO 80522 J. Med. Entomol. 42(6): 923Ð927 (2005) Downloaded from https://academic.oup.com/jme/article/42/6/923/886357 by guest on 29 September 2021 ABSTRACT Many mosquito species are important vectors of human and animal diseases, and others are important nuisance species. To facilitate communication and information exchange among pro- fessional groups interested in vector-borne diseases, it is essential that a stable nomenclature be maintained. For the Culicidae, easily identiÞable genera based on morphology are an asset. Major changes in generic concept, the elevation of 32 subgenera within Aedes to generic status, and changes in hundreds of species names proposed in a recent article demand consideration by all parties interested in mosquito-borne diseases. The entire approach to Aedini systematics of these authors was ßawed by an inordinate fear of paraphyletic taxa or Paraphylyphobia, and their inability to distinguish between classiÞcation and cladistic analysis. Taxonomists should refrain from making taxonomic changes based on preliminary data, and they should be very selective in assigning generic names to only the most important and well-deÞned groups of species. KEY WORDS Aedini classiÞcation, Aedes, Ochlerotatus, paraphylyphobia, mosquito classiÞcation MANY MOSQUITO SPECIES IN the tribe Aedini, a cosmo- In this communication, I brießy review taxonomic politan group represented by 11 genera and Ϸ1,239 categories in a zoological classiÞcation, the Interna- species, are important vectors of human and animal tional Code of Zoological Nomenclature (the Code), diseases, and many others are of considerable eco- the development of generic concept within the Cu- nomic importance as nuisance or pest species. To licidae, classiÞcation within the tribe Aedini and genus facilitate communication and information exchange Aedes, and explain how confusion between classiÞca- among epidemiologists, physicians, veterinarians, vi- tion and cladistic analysis and paraphylyphobia lead to rologists, parasitologists, public health workers, and the classiÞcation of Aedini proposed by Reinert et al. medical entomologists, it is essential that a stable no- (2004). menclature or system of names be maintained. Such communication has seldom been more important Taxonomic Categories and the International Code worldwide, because mosquito-borne diseases draw of Zoological Nomenclature sincere attention from those charged with the respon- sibility of public health at all levels. Mosquito taxon- Unlike the species category, which is deÞned by the biological species concept (Mayr 1969, 1970), omists strive to use new methods of analysis and new the genus and subgenus categories are not based on data sets to address the phylogeny and classiÞcation of a biological concept nor are they strictly deÞned. mosquitoes, and future change in classiÞcation and Usage and deÞnition of generic and subgeneric taxa may nomenclature is inevitable. However, major changes vary among animal groups and even between authors in generic concept, the elevation of 32 subgenera working on the same group of animals. Traditionally, within Aedes (sensu Edwards 1932, 1941) to generic phylogenetic taxonomists deÞned genera as a group of status, and the resultant spelling changes in hundreds related species sharing a common phylogenetic origin of species names by Reinert et al. (2004) demand that differ from species of other related genera by a consideration by all parties interested in mosquito- decided gap in morphological characters (Mayr 1969). borne diseases. Although there are many technical For families such as the Culicidae that are of interest to issues associated with the manuscript of Reinert et al. many professional groups, well-deÞned, easily identiÞ- (2004), visit the following Web-based forum to access able genera based on morphology are an asset. the discussion, http://wrbu.si.edu/forums, I believe The Code (ICZN 1999) provides rules for forming that their entire approach to Aedini systematics was names in the species, subgenus, genus, subfamily, and ßawed by an inordinate fear of paraphyletic taxa or family categories and requires that adjectival species paraphylyphobia, and their inability to distinguish be- names correspond to the gender of the genus in which tween classiÞcation and cladistic analysis. they are placed (Table 1). For example (Table 1), if 924 JOURNAL OF MEDICAL ENTOMOLOGY Vol. 42, no. 6 Table 1. Classificiation of Ae. (Stegomyia) albopictus tema Naturae (Linnaeus 1758), two mosquito species were placed in the single genus Culex L. In 1818, Category Meigen (1818) established two new genera, Anopheles Family Culicidae Meigen and Aedes Meigen, bringing the total number Subfamily Culicinae of genera to three. During the remainder of the Tribe Aedini Genus Aedes 19th century, nine new generic names were pub- Lineage Aedes Lineage lished, including four genera that remain in use today: Subgenus (Stegomyia) Hemagogus Williston, Psorophora Robineau-Desvoidy, Species Group Scutellaris Group Sabethes Robineau-Desvoidy, and Uranotaenia Lynch Species Complex Species Ae. (Stegomyia) albopictus (Skuse) Arribalzaga (Savage and Strickman 2004). In 1900, experimental transmission of human pathogens by The formation of names in the family, subfamily, genus, subgenus, mosquitoes was demonstrated. Patrick Manson ex- and species categories is treated by Articles in the International Code perimentally infected two human volunteers with Downloaded from https://academic.oup.com/jme/article/42/6/923/886357 by guest on 29 September 2021 of Zoological Nomenclature (the Code); above these categories are malaria by bites of Anopheles mosquitoes brought in boldface. The category Tribe is addressed by Recommendations in the Code. Other hierarchical levels sometimes used by biologist such from Italy where they had fed upon a malaria patient; as Lineage, Species Group, and Species Complex are not addressed by and Walter Reed and colleagues working in Havana the Code. demonstrated the transmission of yellow fever virus to healthy volunteers by Aedes (Stegomyia) aegypti L. the species albopictus (Skuse) is placed in the mas- infected on hospitalized patients (Philip and Roze- culine genus Aedes, the correct species name is Aedes boom 1973). These events of 1900 spurred work on the albopictus (Skuse). However, if the feminine sub- taxonomy and biology of mosquitoes. Just 10 yr later, genus Stegomyia was elevated to generic status, and if Theobald (1910) recognized 1,050 species in the species albopictus was placed in the genus Stego- 149 genera (Edwards 1932). In 1906, Dyar and Knab myia, the species name would have to be amended to (1906) developed a classiÞcation of the mosquitoes the feminine form and the correct name would be based on larval morphology and deÞned genera, in- Stegomyia albopicta (Skuse). cluding Aedes, broadly. Howard et al. (1915, 1917), in Some public health workers falsely assume that their classiÞcation of the mosquitoes of North and the Code requires them to accept the results of new Central America and the West Indies, furthered de- taxonomic papers and new classiÞcations. However, veloped the concept that genera should be broadly this is absolutely false. The purpose of the Code is deÞned and easily identiÞable. This broad usage of to promote stability and universality of taxonomic genera within the mosquitoes, including Aedes, was names and to ensure that the valid name of each accepted by Edwards (1917) and by Barraud (1928), species is unique within each genus, according to the and the name Aedes was universally used in this rules of priority. The Code does not provide rules or inclusive sense during the interval 1906Ð2000 (Savage guidance on assigning rank. ClassiÞcations above the and Strickman 2004). Dyar (1928), in his comprehensive species level depend on subjective interpretation of classiÞcation of the mosquitoes of the Americas, deÞned taxonomic data and the philosophy adopted by the genera broadly and generally as they are used today, with investigator. The Code does not restrict freedom of well deÞned internal groups placed as subgenera. In taxonomic thought or action. The Preamble and the 1932, Edwards extended the generic and subgeneric con- Introduction to the Code make this very clear: The cepts employed by Dyar (Dyar and Knab 1906, Dyar Preamble states, “The objects of the Code are to pro- 1928) and placed 1,400 species in 30 genera and 89 sub- mote stability and universality in the scientiÞc names genera and offered a classiÞcation of the Culicidae of the of animals and to ensure that the name of each taxon World that forms the basis for the present classiÞcation. is unique and distinct. All its provisions and recommen- Edwards (1932) pointed out that the use of more inclu- dations are subservient to those ends and none restricts sive generic concepts made the relationships among spe- the freedom of taxonomic thought or actions”; and the cies clearer and the generic limits more easily deÞned. Introduction further states, “Nomenclature does not de- Edwards (1932) also pointed out that smaller groups of termine the inclusiveness or exclusiveness of any taxon, species can be usefully designated by subgeneric names. nor the rank to be accorded to any assemblage of animals, The broad deÞnitions of genera developed by Edwards