Uranotaenia (Pseudoficalbia) unguiculata Edwards

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 : 133-134

Uranotaenia (Pseudoficalbia) unguiculata Edwards

subspecies pefflyi Stone, 1961a —original combination: Uranotaenia unguiculata pefflyi . Distribution: Saudi Arabia ( Stone 1961a).

subspecies unguiculata Edwards, 1913c —original combination: Uranotaenia unguiculata . Distribution: Afghanistan, Albania, Algeria, Armenia, Austria, Azerbaijan, Bulgaria, Crimea, Croatia, Czech Republic, Egypt, France, FYRO Macedonia, Georgia, Germany, Greece, Hungary, India, Iran, Iraq, Israel, Italy, Jordan, Kazakhstan, Kosovo, Kyrgyzstan, Lebanon, Malta, Moldova, Montenegro, Morocco, Pakistan, Portugal, Romania, Russia, Saudi Arabia, Serbia, Slovakia, Spain, Syria, Tajikistan, Tunisia, Turkey, Turkmenistan, Ukraine, Uzbekistan ( Wilkerson et al. 2021, see below regarding Saudi Arabia).

Edwards (1913c) described Ur. unguiculata from a single adult male collected at Tiberias, a city in Israel located on the western shore of the Sea of Galilee. The species is widely distributed in the Mediterranean region, extending northward to Germany, eastward to southern Ukraine and the Volga delta, to middle and southwestern Asia [subspecies pefflyi], Iran and Pakistan ( Becker et al. 2020; Bromley-Schnur 2021).

Stone (1961a) described subspecies pefflyi from eight females and 10 males collected at “Qatif Oasis, Al Hasa Province, Saudi Arabia ”. Today, Qatif Oasis is an urban area known as Qatif or Al-Qatif Governorate on the Persian Gulf coast of Saudi Arabia’s Eastern Province (the former Al Hasa Province is now the largest governorate of the Eastern Province). Wilkerson et al. (2021) listed Saudi Arabia for the distribution of unguiculata , but this obviously came from outdated reports or records published by various researchers, e.g. Alahmed (2012) and Khater et al. (2013), who apparently were unaware of the description of subspecies pefflyi, as noted by Alahmed et al. (2019). In addition to Qatif, specimens identified merely as Ur. unguiculata have been collected at other locations on the Persian Gulf coast of the Eastern Province (Al Dammam and Al Khobar); Al Hasa (or Al Ahsa), the largest city of Al Hasa Governorate located about 65 km west of the Persian Gulf, named after Al Hasa Oasis; and Jezan (Jazan, also spelled Jizan, Gizan or Gazan), a port city and capital of Jazan Province, located on the Red Sea coast directly north of Yemen in southwestern Saudi Arabia ( Wills et al. 1985; Alahmed 2012; Khater et al. 2013). Based on these records, Alahmed et al. (2019) stated that “it is unlikely that the typical form, Ur. unguiculata unguiculata , is present in the country”.

The typical form is recorded as far south as Baghdad and Karbala, located about 100 km southwest of Baghdad, in central Iraq ( Khattat 1955). Subspecies pefflyi has not been recorded north of Qatif in Saudi Arabia, located approximately 320 km southeast of Karbala, Iraq. Alahmed (2012) made collections of adult and larval mosquitoes at “Hafar Al Batin” (also spelled Hafr Al Batin), located about 74 km from the Iraq border in the north of Saudi Arabia’s Eastern Province, but no specimens of Ur. unguiculata were collected.

Filatov (2017) mapped the available distribution records for Ur. unguiculata unquiculata in the western Palaearctic, from Portugal eastward to northern India and Kyrgyzstan, but no records were included for Saudi Arabia. Filatov then applied a species distribution modelling approach, using maximum entropy (Maxent) software, to predict the potential distribution of the subspecies in the region based on habitat suitability determined by comparing environmental data at sites where the subspecies had been recorded with sites across the region. Most areas of the region where the typical form has been recorded were ranked as highly suitable, with some intervening and flanking areas ranked as very highly suitable, including the type locality in Israel, and moderately suitable. Except for a few small areas in northern Saudi Arabia that were rated as moderate or low suitability, all areas of the country where subspecies pefflyi has been recorded were found to be unsuitable. Oddly, sites in Egypt along the Nile River some distance south of the Mediterranean coast and at Siwa Oasis near the Libyan border where Ur. unguiculata has been recorded were also classified as environmentally unsuitable.

For his description of subspecies pefflyi, Stone (1961a) compared specimens from Qatif Oasis with the original description of unguiculata and 10 specimens (adults) from Algeria, France, Iran, Iraq, Israel and Macedonia. He noted that pefflyi agreed “with the typical subspecies in all particulars except as shown in the following comparative statements .

ssp. pefflyi: Smaller , the wing length 1.78–2.38 mm (mean of 10 ♀♀, 10 ♂♂ 1.9 mm). Integument of thorax nearly black, paler only below the pleural scale stripe; dark scales of thorax and abdomen nearly black; usually some dark scales on venter of abdomen; lateral patches of white scales usually confined to terga 5–7.

ssp. unguiculata: Larger , the wing length 2.21–3.4 mm (mean of 5 ♀♀, 5 ♂♂ 2.81 mm). Integument of thorax orange brown, slightly darker just mediad of marginal pale scale stripe of scutum; pleura mostly yellowish brown; dark scales of thorax and abdomen rich orange brown, but distinctly not black brown; scales of venter all pale; pale lateral scale patches of abdomen usually start on tergum 2.

The adults of the typical subspecies have been described by a number of authors ( Edwards 1913c; Barraud 1934; Harant et al. 1952; Senevet & Andarelli 1959; Gutsevich et al. 1971, 1974; Becker et al. 2020), but most of the information in the descriptions is not comparable with the information provided by Stone (1961a). None of the authors measured the length of the wings and, not surprisingly, they do not agree on the color of the thoracic and abdominal scaling. Barraud (1934) is the only author who mentioned the color of the thoracic integument: Mesonotum dark brown or black, not orange brown (Stone); pleura brownish-black, not mostly yellowish brown (Stone).

It is obvious that Ur. unguiculata in Saudi Arabia is only found in isolated locations. A question which cannot be answered at this time is whether subspecies pefflyi, as described by Stone, can be identified as such in areas other than Qatif Oasis—after all, isolated populations more recently found in other parts of the country ( Wills et al. 1985; Alahmed 2012; Khater et al. 2013) have been identified as merely “ unguiculata ”.

Our impression is that the isolated populations in Saudi Arabia are relicts of a species that was more widespread in the past, with populations throughout the Arabian Peninsula until it began to dry up and become desert about 5,000 years ago ( Brand 2018). In as much as the populations in Saudi Arabia are readily identifiable as Ur. unguiculata , and the available data indicate that it is a morphologically variable species, we believe it is in the best interests of science to regard pefflyi as nothing more than a morphological variant of a single species. Consequently, we hereby formally classify subspecies pefflyi as a synonymous name: pefflyi Stone, 1961a, junior subjective synonym of Uranotaenia (Pseudoficalbia) unguiculata Edwards, 1913c . Synonym pefflyi, which is currently listed as a species in the Encyclopedia of Life, should be removed from the list of recognized species of the genus Uranotaenia .