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United States Department of Agriculture

Agricultural Research Service

Title: Phylogeny and Classification of Aedini (Diptera: Culicidae) Based on Morphological Characters of All Life Stages

Authors
item Reinert, John
item Harbach, Ralph - NATURAL HISTORY MUSEUM
item Kitching, Ian - NATURAL HISTORY MUSEUM

Submitted to: Zoological Journal of the Linnean Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 1, 2004
Publication Date: December 1, 2004
Citation: Reinert, J.F., Harbach, R.E., Kitching, I.J. 2004. Phylogeny and classification of aedini (diptera: culicidae) based on morphological characters of all life stages. Zoological Journal of the Linnean Society. 142:289-368.

Interpretive Summary: Mosquitoes suck blood and transmit disease agents that cause sickness and death in animals and humans. Before efforts to control mosquitoes can be made, however, accurate identification of the species involved is required. This information, which is based on microscopic features of the external anatomy of the mosquito, is used to ensure that insecticides, biological control agents, and other interventions are applied in an effective and safe manner. ARS scientists at the Center for Medical, Agricultural, and Veterinary Entomology in Gainesville, FL are working continuously to develop new and improved techniques for mosquito identification. The information resulting from this research allows animal and public health specialists and pest/vector control personnel to identify mosquito species accurately and quickly, and to apply mosquito control measures in a safe and timely manner.

Technical Abstract: Higher-level relationships within Aedini, the largest tribe of Culicidae, are explored using morphological characters of eggs, fourth-instar larvae, pupae, and adult females and males. One hundred seventy-two characters were examined for 119 exemplar species representing the 12 genera and 56 subgenera recognized within the tribe. The data for immature and adult stages were analysed separately and in combination using equal (EW) and implied weighting (IW). Since the current classification of Aedini is based mainly on adult morphology, we first tested whether adult data alone would support the current classification. Overall, the results of these analyses did not reflect the generic classification of the tribe. The tribe as a whole was portrayed as a polyphyletic assemblage of Aedes and Ochlerotatus within which eight (EW) or seven (IW) other genera were embedded. Strict consensus trees (SCTs) derived from analyses of the immature stages data were almost completely unresolved. Combining the adult and immature stages data resulted in fewer most parsimonious cladograms (MPCs) and a more resolved SCT than was found when either of the two data subsets was analysed separately. However, the recovered relationships were still highly unsatisfactory. Except for the additional recovery of Armigeres as a monophyletic genus, the groups recovered in the EW analysis of the combined data were those found in the EW analysis of adult data. The IW analysis of the total data yielded eight MPCs consisting of three sets of two mutually exclusive topologies that occurred in all possible combinations. We carefully studied the different hypotheses of character transformation responsible for each of the alternative patterns of relationship but were unable to select one of the eight MPCs as a preferred cladogram. Overall, the relationships within the SCT of the eight MPCs were a significant improvement over those found by equal weighting. Aedini and all extant genera except Ochlerotatus and Aedes were recovered as monophyletic. Ochlerotatus formed a polyphyletic assemblage basal to Aedes. This group included Haemagogus and Psorophora, and also Opifex in a sister-group relationship with Oc. (Not.) chathamicus. Aedes was polyphyletic relative to seven other genera, Armigeres, Ayurakitia, Eretmapodites, Heizmannia, Udaya, Verrallina and Zeugnomyia. With the exception of Ae. (Aedimorphus), Oc. (Finlaya), Oc. (Ochlerotatus) and Oc. (Protomacleaya), all subgenera with two or more species included in the analysis were recovered as monophyletic. Rather than leave the generic classification of Aedini in its current chaotic state, we decided a reasonable and conservative compromise classification would be to recognize as genera those groups that are "weighting independent", i.e., those that are common to the results of both the EW and IW analyses of the total data. The SCT of these combined analyses resulted in a topology of 29 clades, each comprising between two and nine taxa, and 30 taxa (including Mansonia) in an unresolved basal polytomy. In addition to ten genera, Armigeres, Ayurakitia, Eretmapodites, Haemagogus, Heizmannia, Opifex, Psorophora, Udaya, Verrallina and Zeugnomyia, generic status is proposed for 32 subgenera of Aedes and Ochlerotatus, including nine monobasic subgenera within the basal polytomy, i.e., Ae. (Belkinius), Ae. (Fredwardsius), Ae. (Indusius), Ae. (Isoaedes), Ae. (Leptosomatomyia), Oc. (Abraedes), Oc. (Aztecaedes), Oc. (Gymnometopa) and Oc. (Kompia), three small subgenera within the basal polytomy that are undoubtedly monophyletic, i.e., Ae. (Huaedes), Ae. (Skusea) and Oc. (Levua), and another 20 subgenera that fall within the resolved part of the SCT, i.e., Ae. (Aedes), Ae. (Alanstonea), Ae. (Albuginosus), Ae. (Bothaella), Ae. (Christophersiomyia), Ae. (Diceromyia), Ae. (Edwardsaedes), Ae. (Lorrainea), Ae. (Neomelaniconion), Ae. (Paraedes), Ae. (Pseudarmigeres), Ae. (Scutomyia), Ae. (Stegomyia), Oc. (Geoskusea), Oc. (Halaedes), Oc. (Howardina), Oc. (Kenknightia), Oc. (Mucidus), Oc. (Rhinoskusea) and Oc. (Zavortinkius). A clade consisting of Oc. (Fin.) kochi, Oc. (Fin.) poicilius and relatives is raised to generic rank as Finlaya, and Downsiomyia Vargas is reinstated from synonymy with Finlaya as the generic name for the clade comprising Oc. (Fin.) leonis, Oc. (Fin.) niveus and their relatives. Three other species of Finlaya, Oc. (Fin.) chrysolineatus, Oc. (Fin.) geniculatus and Oc. (Fin.) macfarlanei, fall within the basal polytomy and are treated as Oc. (Finlaya) incertae sedis. Ochlerotatus (Ochlerotatus) is divided into three lineages, two of which, Oc. (Och.) atropalpus and Oc. (Och.) muelleri, are part of the basal polytomy. The remaining seven taxa of Oc. (Ochlerotatus) analysed, including the type species, form a reasonably well-supported group that is regarded as Ochlerotatus s.s. Ochlerotatus (Rusticoidus) is retained as a subgenus within Ochlerotatus s.s. Ochlerotatus (Nothoskusea) is recognized as a subgenus of Opifex based on two unique features that support their sister-group relationship. A new genus, Tanakaius gen. nov., is proposed for Oc. (Fin.) togoi and the related species Oc. (Fin.) savoryi. The taxonomic status and generic placement of all currently valid species of Aedini are listed in an appendix.

Last Modified: 4/18/2014
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