Research Article |
Corresponding author: Ximo Mengual ( x.mengual@leibniz-zfmk.de ) Academic editor: Burgert Muller
© 2018 Ximo Mengual.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Mengual X (2018) A new species of Ischiodon Sack (Diptera, Syrphidae) from Madagascar. African Invertebrates 59(1): 55-73. https://doi.org/10.3897/afrinvertebr.59.24461
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The flower fly genus Ischiodon Sack (Diptera, Syrphidae) is revised and a new species, Ischiodon astales sp. n., is described from Madagascar. Additionally, a lectotype for Ischiodon aegyptius is designated and the first records of Ischiodon scutellaris for the Arabian Peninsula are reported. Diagnoses, illustrations, synonymies and distributional data are given for all described species, as well as an identification key to all known species.
identification key, flower flies, hoverflies, Ischiodon astales , Afrotropical Region
The genus Ischiodon Sack, 1913 (Diptera, Syrphidae) is a small, but very characteristic genus, with a very broad distribution and a taxonomic history full of confusion and synonyms (
The confusion of Ischiodon as a valid genus is due to its superficial morphological resemblance with the genus Simosyrphus Bigot, 1882. This confusion started when
Ischiodon comprises three species with quite distinct distributions: I. feae (Bezzi, 1912) is endemic of the Cape Verde Islands, I. aegyptius (Wiedemann, 1830) is mainly present in Africa and southern Europe and I. scutellaris (Fabricius, 1805) occurs in the Oriental and Australasian Regions. Larvae of I. aegyptius and I. scutellaris have been reported feeding on aphids (Hemiptera, Aphididae) mostly, but there are a few records on thrips (Thysanoptera), whiteflies (Hemiptera, Aleyrodidae) and caterpillars (Lepidoptera) (
The aim of this study is to revise the genus Ischiodon and describe a new species from Madagascar, as well as to provide an identification key for all known species of this genus. In addition, a lectotype is designated for Syrphus aegyptius Wiedemann, 1830 and the first records of I. scutellaris from the UAE are reported.
Differential diagnoses, synonymies and distributions are given for all studied species. The new species is described in full, with terminology following
In the description of type labels, the contents of each label are enclosed within double quotation marks (“ ”), italics denote handwriting and the individual lines of data are separated by a double forward slash (//). At the end of each record, between square brackets ([]) and separated by a comma, the number of specimens and sex, the holding institution and the unique identifier or number are given.
All measurements are in millimetres and were taken using a reticule in a Leica M165 C microscope. Photographs were composed using the software Zerene Stacker 1.04 (Richland, Washington, USA), based on images of pinned specimens taken with a Canon EOS 7D mounted on a P–51 Cam-Lift (Dun Inc., VA, USA) and with the help of Adobe Lightroom (version 5.6). Simple-Mappr (
Ischiodon trochanterica Sack, 1913, by monotypy; junior synonym of Scaeva scutellaris Fabricius, 1805.
(adapted from
In males of I. aegyptius and I. scutellaris, the ventral surface of the metatrochanter has a slender or moderately stout, cylindrical, apically acute process (calcar) of varying length. In males of I. aegyptius and I. feae, the inner (mesial) claw of the protarsus has a dorsal preapical projection, or flange, which gives the claw a truncated appearance (Fig.
Ischiodon is derived from the neuter adjective ischion, from the Greek ischion meaning “hip, coxa” (
Several authors (including the present author) used the species epithet of Ischiodon aegyptium in neuter form. Ischidon must be treated as a masculine gender and all species names must follow this gender except nouns in apposition. Thus, the correct species epithet is Ischiodon aegyptius.
Musca
nigra
Forsskål, 1775: xxiv. Type-locality: Egypt, Arabia. Type material most likely lost (not found in the digitised type collection of the
Syrphus
aegyptius
Wiedemann, 1830: 133. Type-locality: Eritrea and Ethiopia, as Abyssinia, here restricted. Lectotype ♂,
Syrphus senegalensis Guérin-Méneville, 1832: pl. 99. [Description in 1844: 545]. Type-locality: Senegal.
Sphaerophoria annulipes Macquart, 1842: 103. Type-locality: Egypt.
Syrphus longicornis Macquart, 1842: 154. Type-locality: South Africa.
Syrphus natalensis Macquart, 1846: 262 (134). Type-locality: South Africa, ‘Port Natal’.
Syrphus felix Walker, 1852: 229. Type-locality: Canary Is.
Syrphus brachypterus Thomson, 1869: 496. Type-locality: Madeira.
Sphaerophoria pyrrura Bigot, 1884: 99. Type-locality: Senegal.
Sphaerophoria borbonica Bigot, 1884: 100. Type-locality: Réunion Is.
Xanthogramma catalonicum Andreu, 1926: 110. Type-locality: Spain: Prov. Barcelona, Moya.
Very common species in the Afrotropical region with yellow markings on abdomen reaching the lateral margins (Fig.
African continent and archipelagos, southern Europe, Israel and Arabian Peninsula.
More than 300 specimens from UAE, Israel, Cyprus, Morocco, Canary Islands, Madagascar, Kenya, The Gambia, Central African Republic, Zimbabwe and South Africa.
Amongst the syntypes, deposited at the Senckenberg Forschungsinstitut und Naturmuseum (
Some authors (
Females and males of this new species do not have a calcar on the metatrochanter and they are easy to distinguish from other species since the two broad, yellow maculae on tergite 2 do not reach the lateral margins (Figs
Male: Head (Fig.
Thorax (Fig.
Abdomen (Fig.
Female: Similar to male except for normal sexual dimorphism and as follows: frons black on dorsal 1/3, yellow on ventral 2/3 with a variable medial brownish orange vitta.
Variation: Due to the small number of specimens, one must expect variability in the coloration of the abdomen, legs and female frons, as in other Ischiodon species.
Length (N=4): Body, 10.0 mm (9.0–12.0 mm); wing, 7.7 mm (7.5–8.0 mm).
Species known from the southern regions of Atsimo-Andrefana and Anosy, part of the former Toliara Province, Madagascar (Fig.
The specific epithet is derived from the Greek astales meaning unarmed, unclad (
Madagascar: Atsimo-Andrefana Region, Mikea forest, NW of Manombo, 22°54.22'S, 43°28.53'E.
Type material. Holotype, male, pinned with genitalia in microvial, deposited in the
All specimens of this new species were collected using Malaise traps in different habitats. The male holotype was collected in a deciduous dry forest, while females CASENT 2210150 and CASENT 2210121 were collected in dry spiny forests and the female CASENT 2210162 in a gallery forest. On the other hand, the female
Syrphus
feae
Bezzi, 1912: 407. Type,
Very distinct Ischiodon species with a darker overall coloration (Figs
Only known from Cape Verde.
Cape Verde: São Vicente Is., Monte Verde, 25–29.xi.1953, Lindberg [1♂,
Ischiodon feae (Bezzi), male http://id.luomus.fi/GJ.1984: A Habitus, lateral view B Frontal view C Habitus, dorsal view D Labels E Wing F Acropod and fifth tarsomere of the fore leg, dorsal view G Male genitalia, lateral view H Hypandrium, ventral view. (E–H from
Scaeva
scutellaris
Fabricius, 1805: 252. Type-locality: India: Tamil Nadu, Tharangambadi. Syntypes,
Syrphus coromandelensis Macquart, 1842: 149. Type-locality: India: ‘Cote de Coromandel’.
Sphaerophoria annulipes Macquart, 1855: 116. Type-locality: Marquesas Is.
Syrphus splendens Doleschall, 1856: 410. Type-locality: Indonesia: Java.
Syrphus nodalis Thomson, 1869: 497. Type-locality: French Polynesia: Society Is., Tahiti.
Syrphus erythropygus Bigot, 1884: 87. Type-locality: ‘Indes’.
Syrphus ruficauda Bigot, 1884: 96. Type-locality: New Caledonia.
Melithreptus novaeguineae Kertesz, 1899: 178. Type-locality: Papua New Guinea: Astrolabe Bay, Erima.
Ischiodon trochanterica Sack, 1913: 6. Type-locality: Taiwan: Kanshizei, Puli as ‘Polisha’, Suihenkyaku, Tainan and Takao.
Melithreptus ogasawarensis Matsumura, 1916: 23. Type-locality: Japan: Bonin Is., Ogasawara-jima.
Ischiodon boninensis Matsumura, 1919: 128. Type-locality: Japan: Bonin Is., Chichi-jima, Ogasawara-jima.
Epistrophe platychiroides Frey, 1946: 164. Type-locality: Philippines: Luzon, Quezon, Atimonan.
Ischiodon penicillatus Hardy, 1952: 363; nomen nudum.
Epistrophe magnicornis Shiraki, 1963: 141. Type-locality: Micronesia: Chuuk State, Weno Is.
Sphaerophoria macquarti Goot, 1964: 220. New name for annulipes Macquart.
Very widespread species with yellow abdominal marking reaching lateral margins (Fig.
From Greece, eastwards to Caucasus, Kazakhstan, Iran, Arabian Peninsula south to Indomalayan region, China, Japan, Taiwan and Australasian and Oceanian regions except Hawaii. I. scutellaris has not been reported from Korea (
More than 150 specimens from Greece, UAE, Kazakhstan, Iran, Nepal, Indonesia, Thailand, Taiwan, Australia, New Caledonia and French Polynesia. The syntypes of Scaeva scutellaris Fabricius, 1805 were not studied for the present study.
In their excellent treatment of the flower fly fauna of the Arabian Peninsula,
1 | Males: eyes meeting on frons (Figs |
2 |
– | Females: eyes separated (Fig. |
5 |
2 | Metatrochanter without a calcar | 3 |
– | Metatrochanter with a calcar (spur) (Figs |
4 |
3 | Face entirely yellow (Fig. |
astales sp. n. |
– | Face yellow with a medial black vitta (Fig. |
feae (Bezzi) |
4 | Calcar on metatrochanter long, more than three times longer than wide (Fig. |
aegyptius (Wiedemann) |
– | Calcar on metatrochanter shorter, about two times longer than wide (Fig. |
scutellaris (Fabricius) |
5 | Yellow abdominal maculae on terga 2 and 3 not reaching lateral margins (Fig. |
6 |
– | Yellow abdominal maculae on terga 2 and 3 reaching lateral margins | 7 |
6 | Face entirely yellow (Fig. |
astales sp. n. |
– | Face yellow with a medial black vitta (Fig. |
feae (Bezzi) |
7 | Typical female: tergite 2 usually with a transverse yellow fascia, sometimes with two yellow maculae with pointed inner margin (African continent and archipelagos, southern Europe, Israel, Arabian Peninsula) | aegyptius (Wiedemann) |
– | Typical female: tergite 2 usually with two yellow maculae with rounded inner margin (from Greece, Caucasus, Kazakhstan, Iran, Arabian Peninsula south to Indomalayan Region, Australasian and Oceanian regions, Japan) | scutellaris (Fabricius) |
Note: Females of I. aegyptius and I. scutellaris cannot be distinguished as the pattern of tergite 2 is very variable. At this moment, conspecific males, DNA barcodes and/or collecting locality may help to distinguish them. |
A new species of Ischiodon is described from the southern regions of Madagascar. It should be noted that the male holotype and the four female paratypes of I. astales sp. n. were found amongst more than 200 specimens of Ischiodon aegyptius collected over several years (2002–2008) using Malaise traps (specimens deposited in the
Ischiodon scutellaris has reached the Mediterranean Basin and it is present in Greece, Crimea Peninsula and Turkey and might eventually reach northern areas of the Balkan Peninsula. In contrast, the species present in the Iberian Peninsula, Macaronesia, Italy, northern parts of the African continent, Cyprus and Israel is I. aegyptius. It seems that there is an overlapping area of these two species including the southern region of Turkey and Iran, where both species have been reported (
My most sincere thanks to Martin Hauser for sharing with me the information about syrphid fauna from the UAE. Thanks to Gunilla Ståhls (
Table S1. Localities for the specimens of Ischiodon astales Mengual, sp. n. (Geographical coordinates)