Anopheles (Cellia) cinereus Theobald, 1901

Harbach, Ralph E. & Wilkerson, Richard C., 2023, The insupportable validity of mosquito subspecies (Diptera: Culicidae) and their exclusion from culicid classification, Zootaxa 5303 (1), pp. 1-184 : 62-64

Anopheles (Cellia) cinereus Theobald

subspecies cinereus Theobald, 1901a —original combination: Anopheles cinereus . Distribution: Algeria, Chad, Egypt, Eritrea, Eswatini, Ethiopia, FYRO Macedonia, Georgia, Greece, Guinea-Bissau, Israel (and Gaza Strip and West Bank), Italy (includes Sardinia and Sicily), Jordan, Libya, Lithuania, Kenya, Madeira, Malawi, Morocco, Mozambique, Namibia, Niger, Portugal, Republic of the Congo, Republic of South Africa, Saudi Arabia, Somalia, Spain, Sudan, Tanzania, Tunisia, Uganda, Ukraine, Yemen, Zimbabwe ( Wilkerson et al. 2021).

subspecies hispaniola ( Theobald, 1903a) —original combination: Myzomyia hispaniola (subspecific status by Senevet & Rioux 1960 and Ribeiro et al. 1980). Distribution: Algeria, Bulgaria, France, Greece, Italy, Morocco, Spain (including Canary Islands), Yemen ( Wilkerson et al. 2021).

Theobald (1901a) described cinereus from Salisbury, Mashonaland [Harare, Zimbabwe] ( Townsend 1990). Selected characters include: Maxillary palpus with four white bands, including one at the apex; antenna with a few white scales on one side of the proximal flagellomeres (not shown in Theobald’s fig. 43b). A text description of the wing markings was provided but the accompanying illustration (fig. 44) shows only venation. However, there is a color illustration of the habitus in Theobald (1901a [plates]: fig. 7, pl. II). He wrote in summary: “At first sight they look like large A. funestus , but the clear pale bases to the legs separate it at once, as well as the large wings and the marked character of the jet-black legs with the white spots at the knees and apices of the tibiae.” Theobald (1903a) described and contrasted Myzomyia hispaniola to Myzomyia turkhudi Liston, 1901 , noting that both species shared a black palpomere 5 [in contrast to cinereus ]. The nominal taxon hispaniola has “tarsi unbanded, and apices of all the femora and tibiae with a pale yellow spot.” As for cinereus in Theobald (1901a), the wing of hispaniola was described but only the venation illustrated. A color habitus illustration was not provided, as it was for cinereus . For cinereus, Theobald (1901a [plates]) illustrated pale fringe scales at the apices of all veins except 1A. Theobald (1903a) described hispaniola with “fringe brown, with pale spots where the veins join the costa except at the lower branch of the fifth and the sixth”, i.e. at the apices of veins Cu and 1A. For hispaniola , both Romero Viamonte (1949) and Ribeiro et al. (1980) illustrated pale fringe spots at the apices of all veins, including 1A, while Gillies & de Meillon (1968) showed cinereus with all the veins, except at 1A, ending at pale fringe. We have not found this character noted elsewhere, but it could have diagnostic value.

Below we describe the unstable taxonomic history of the nominal species cinereus and hispaniola . This has been the result of an incomplete understanding of morphological variability and dubious use of the subspecies concept. Currently, the commonly understood distributions for these nominal taxa are Afrotropical for cinereus and Mediterranean for hispaniola . Much morphological and biological diversity remains to be understood, which we think will eventually be explained by the existence of a species complex.

The two nominal taxa are quite similar morphologically but occur in very different biogeographical zones. Since they are so similar, the two names have been used inconsistently. Evans (1938) treated cinereus as a species in the Afrotropical Region (as Ethiopian Region) and included hispaniola as a possible synonym of turkhudi . Romeo Viamonte (1949, 1950) and Aitken (1953) both treated hispaniola as a species. De Meillon (1947) provided the most comprehensive and illustrated description of cinereus , including the egg. Gillies & de Meillon (1968) updated the description of de Meillon (1947) and addressed the possibility that hispaniola was a subspecies of cinereus . They stated: “As pointed out by Mattingly & Knight (1956), the separation of this species [ hispaniola ] from cinereus is very difficult if not impossible, which led Senevet & Rioux (1960) to reduce it to the status of a subspecies of cinereus . They summarized the characteristics of hispaniola as follows: adult, reduction or absence of apical pale band on ♀ palps [maxillary palpi]; pupa, hair [seta] l-IV more often simple [single]; larva, most specimens with mouth-brushes [palatal brushes] not mounted laterally.” The biological and taxonomic significance of the lateral position of the palatal brushes in these species has not been investigated further. Mattingly (1969) pointed out that species in the Cinereus Group (of Gillies & de Meillon 1968) have eggs that lack floats and a much reduced frill, which remain “only as a small patch near the anterior end. These eggs hang vertically in the water and sink readily. Loss of the float is thought to be adaptive to oviposition among the filamentous algae on which the larvae feed by means of specialized mouthparts.” We note that the extent of the frill seems to vary in published illustrations (e.g. Edwards 1921d, fig. 1l; Romeo Viamonte 1949: fig. 1; Romeo Viamonte 1950: fig. 27; Gillies & de Meillon 1968, pl. 100g), but this has not been documented. As explained by Romeo Viamonte (1949, 1950), Edwards’s figure 11 is incorrectly labelled as the egg of An. turkhudi .

Gillies & de Meillon (1968) agreed [with caveats] with Raffaele & Coluzzi (1961) that differences in the pharynx [cibarial teeth of adult females] justified the recognition of cinereus and hispaniola as separate species. Dahl & White (1978), however, synonymized hispaniola with cinereus in the Balkans without comment. This synonymy was followed by Ward (1984) and Ramsdale (1998). Ribeiro et al. (1980) referred to the taxon in Portugal as cinereus hispaniola . Hammadi et al. (2009) considered hispaniola as a species in Algeria and Kyalo et al. (2017) considered cinereus to be a species in the Afrotropical Region, but did not mention hispaniola . Robert et al. (2019) acknowledged the two names, and identification problems, in their distribution chart for Euro-Mediterranean mosquitoes but did not attempt to resolve the issue, and instead combined them as “ sensu lato ”. Irish et al. (2020) used the name cinereus but also noted several instances of usage of the name hispaniola in the Afrotropical Region. Becker et al. (2020) are the only authors who considered and compared both nominal taxa in the same publication, but wrote: “Therefore, An. cinereus is described here, despite the complicated situation of its real distribution”, and further noted: “The status of hispaniola is still rather undefined.” They discussed and gave descriptions of both cinereus sensu stricto and cinereus hispaniola , with keys to adult females, male genitalia and larvae of the latter form. Their treatment was only for the separation of the taxon from other European species of the subgenus Cellia , with no attempt to resolve the composition of cinereus sensu lato.

To justify retaining hispaniola as a subspecies, Ribeiro et al. (1980) stated: “In the absence of other information concerning experimental or natural hybridization between both forms, it is classical to adopt a subspecific treatment in such a situation [ Mayr et al. (1953); Mayr (1963); Mayr (1969)]” [the dates of the three publications are replacements here for the original reference numbers 32, 33 and 34, respectively]. As stated by Mayr et al. (1953), “It is preferable for various reasons to treat doubtful allopatric populations as subspecies.” We believe this approach is arbitrary and has caused considerable confusion. Further work is needed to morphologically and genetically characterize the two nominal taxa. Morphological differences are not well documented and there is a very significant difference in biogeographical occurrence. To further confuse the issue, we think there is enough morphological variability to suggest that this is probably a complex of species. For these reasons, and to draw attention to the need to fully understand hispaniola in comparison to cinereus , we herein afford it species status: Anopheles (Cellia) hispaniola Theobald, 1903 . The country occurrence records listed above, especially for hispaniola , should be used with caution until the genetic identities of the two species are resolved. Anopheles hispaniola is currently listed as a species in the Encyclopedia of Life.

Anopheles cinereus has a single synonym, An. jehafi Patton, 1905 (type locality: Jebel Jehaf, D’thalia, Yemen); An.hispaniola has three sysnonyms, Pyretophorus myzomyifacies Theobald, 1907 (type locality: Algeria), An. italicus Raffaele, 1928 (type locality: Calabria, Italy) and Myzomyia rifenus Baeza Cuéllar, 1933 (type locality: Er Rif, Morocco). In addition to the uncertainty about the genetic identities of cinereus and hispaniola , these synonymized nominal species further suggest the existence of a species complex. Until further data become available, it seems appropriate to retain the current synonymies.