Heteralonia Rondani, 1863

Greathead, D. J. & Evenhuis, N. L., 2001, Annotated keys to the genera of African Bombylioidea (Diptera: Bombyliidae; Mythicomyiidae), African Invertebrates 42 (1820), pp. 105-224 : 200-201

Heteralonia Rondani

Heteralonia Rondani, 1863: 57 [1864: 57]. Type species: Exoprosopa oculata Macquart, 1840 (as ‘ occulta ’), by monotypy.

Comments: Heteralonia was erected to contain species of Exoprosopa with cell r 2+3 divided into two by a crossvein. Bowden (1975 b) found that species in other subgenera of Exoprosopa sensu Bezzi (1924) ( Acrodisca , some Defilippia , Isotamia , Mesoclis, Metapenta and Zygodipla) all have small male genitalia with a simple axe-head shaped epiphallus and weak ejaculatory apodeme, concealed between the fused gonocoxae, as well as a tendency toward unstable wing venation, a characteristic dark wing pattern and dark vestiture. Consequently, he grouped all these species in Heteralonia , and divided it into subgenera based on wing venation and the degree of reduction of the front legs. His revised concept of Heteralonia was misinterpreted by some authors, who found the characters ambiguous, and therefore doubted its validity or reduced its scope to include only some of the subgenera. However, it has been found that species of Heteralonia sensu Bowden all have a similar spermathecal shape – small with narrow, tubular, thick-walled, unpigmented bulbs – which provides an unambiguous apomorphy to define the genus. The subgeneric characters, if interpreted strictly, produce some anomalies: some southern African Acrodisca -like species lacking the appendix (and so appear to belong strictly to Homolonia ) have the typical wing-pattern, body size and coloration of Acrodisca spp.; similarly, some Arabian Zygodipla -like species lack either a divided or closed cell r 5, but have the wing pattern and coloration of this subgenus; some Indian species can be placed in either Acrodisca or Isotamia , having the characters of both subgenera, and so on. Thus, the subgenera of Heteralonia are ill-defined, and are retained only as an aid to identification; the number of species in each is open to interpretation. Keys: Palaearctic, Engel (1932 –7), Paramonov (1928); Afrotropical, Bezzi (1924); Ghana, Bowden (1964); Eritrea /northern Ethiopia, Greathead (1967); Senegal, François (1972); southern Africa, Hesse (1956) all as Exoprosopa .

Hosts: One reliable record only, from the cocoon of a pompilid ( Yeates & Greathead 1997). The record from a locust ( du Merle 1975) is dubious.

Subgenus Acrodisca Bezzi

Acrodisca Bezzi, 1921 a: 138 , 139 [1922 a: 85; 1923: 332; 1924: 234] (as subgenus of Exoprosopa Macquart ). Type species: Exoprosopa angulata Loew, 1860 , by subsequent designation (Bezzi, 1924: 234).

Cladodisca Bezzi, 1922 b: 105 [1922 c: 143–44; 1923: 332; 1924: 143] (as subgenus of Exoprosopa Macquart ). Type species: Exoprosopa munda Loew, 1869 , by monotypy.

Distribution: Afrotropical, Palaearctic and Oriental Regions. North Africa: Egypt: 1

species; Heteralonia serpentata (Klug) .Africa South of the Sahara: 23 species. Socotra:

1 species; H. insularis (Ricardo) .

Subgenus Heteralonia Macquart

Distribution: Afrotropical Region: 2 species; Heteralonia oculata Macquart ( Senegal to Eritrea and East Africa), H. kaokoensis (Hesse) ( Namibia) .

Subgenus Homolonia Bowden

Mima Meigen, 1820: 175 . Type species: Anthrax phaeoptera Wiedemann, 1820 , by subsequent designation (Coquillett, 1910: 570).

Homolonia Bowden, 1975 b: 319 . Type species: Anthrax megerlei Meigen, 1820 , by original designation.

[ Mima was originally proposed in synonymy but was made available by Coquillett’s (1910: 570) type designation and treatment of it as a senior synonym of Exoprosopa Macquart. Despite its being an available name, the type species of Mima could not be recognized until recently because of its vague original description. Publication of Meigen’s color plates ( Morge, 1976) confirms the identity of Anthrax phaeoptera as very similar to, if not the same as, Anthrax megerlei Meigen, 1820 , the type species for Homolonia Bowden, 1975 . To accept the generic concept of Mima would cause instability in the taxonomy of this group of flies. Until an application is submitted to the I.C.Z.N. to formally suppress Mima in favor of Homolonia , this paper treats Homolonia as the valid genus-group name for this group of flies.]

Distribution: Afrotropical, Palaearctic and Oriental Regions. North Africa: 3 species;

Heteralonia aegina (Wiedemann) , H. megerlei (Meigen) , H. vesperugo (Costa) . Africa

South of the Sahara: 21 species. Madagascar: 1 species; H. dolichoptera (Bezzi) .

Subgenus Isotamia Bezzi

Isotamia Bezzi, 1912: 606 , 627 (as genus). Type species: Isotamia daveyi Bezzi, 1912 , by original designation. Francoisia Hesse, 1952: 1 (as genus). Type species: Francoisia sulcifacies Hesse, 1952 [= Isotamia daveyi Bezzi, 1912 ], by original designation.

Ogilviella Paramonov, 1954: 26 (as genus). Type species: Ogilviella tridentata Paramonov, 1954 [= Isotamia daveyi Bezzi, 1912 ], by monotypy.

Stenolonia Bowden, 1975 b: 319 . Type species: Exoprosopa loxospila Hesse, 1956 , by original designation. Distribution: Africa and Oriental Regions. North Africa: Egypt: 1 species; Heteralonia spiloneura (Bezzi) . Africa South of the Sahara: 6 species, including the following new species.