Ann. Natal Mus. Vol. 35 Pages 61-69 Pietermaritzburg October, 1994 Afrotropical Asilidae (Diptera) 24. Afroholopogon, a new genus for Afrotropical species previously allocated to Cyrtopogon Loew, Heteropogon Loew and Holopogon Loew (Stenopogoninae) by Jason G. H. Londt (Natal Museum, P. Bag 9070, Pietermaritzburg, South Africa) ABSTRACT Evidence is provided to show that all Afrotropical taxa previously assigned to Cyrtopogon Loew, Heteropogon Loew and Holopogon Loew are not congeneric, and should be combined in a separate genus-group taxon, Afroholopogon gen. n. INTRODUCTION In 1847 Hermann Loew described three genera, Cyrtopogon, Heteropogon and Holopogon, based on Palaearctic genotypes, to which many species, from almost every zoogeographical region, have subsequently been added (Table 1). Research currently being done on the Afrotropical genera of the subfamily Stenopogoninae, with the aim of developing an adequate key (Londt 1990), has brought into question the assignation of African species to these primarily Holarctic genera. An examination of Holarctic material (Table 2), together with an extensive collection of Afrotropical specimens, all housed in the Natal Museum, has convinced me that no true representatives of Loew's genera inhabit the afrotropics, and that all previously named species should be combined under a single genus-group taxon, here provided. TABLE I Number of species assigned to Loew's genera Cyrtopogon, Heteropogon and Holopogon, as recorded in the most recent catalogues (Oriental - Oldroyd 1975; Palaearctic - Lehr 1988; Nearctic - Martin & Wilcox 1965; Neotropical-Martin & Papavero 1970; Afrotropical-Oldroyd 1980; Australasian - Daniels 1989). Genus .O0';<=:. :l) O0.~<~.~..l) Z.O<~.J) 'OZg50O<.J l) . <'O<b500Ot:J l. <.Ob;:<~>~;:=I ;lll Cyrtopogon 3 27 70 1 Heteropogon 25 17 8 7 Holopogon 36 17 6 7 61 62 ANNALS OFTHE NATAL MUSEUM, VOL. 351994 TABLE 2 A comparison of Holarctic representatives of Loew's genera Cyrtopogon, Heteropogon and Holopogon with Afrotropical species previously assigned to these genera. * =g enotype. Characters (see below) Taxon A B C D E F G H Cyrtopogon Nearctic anomalus Cole, 1919 (USA) 2 2 2 2 2 auripilosus Wilcox & Martin, 1936 (USA) 2 2 2 2 2 callipedilus Loew, 1874 (USA) 2 2 2 2 2 montanus Loew, 1874 (Canada, USA) 2 2 2 2 2 sudator Osten Sacken, 1877 (USA) 2 2 2 2 2 Palaearctic lateralis (Fallen, 1814) (Bulgaria) 2 2 2 2 2 maculipennis (Macquart, 1834) (Bulgaria) 2 2 2 2 2 ruficornis * (Fabricius, 1794) (Bulgaria) 2 2 2 2 2 Afrotropical africanus Ricardo, 1925 (South Africa) 2 2 2 2 2 2 2 Heteropogon Nearctic cirrhatus (Osten Sacken, 1877) (USA) 2 1 2 2 dorothyae Martin, 1962 (Mexico) 2 2 2 2 johnsoni (Back, 1904) (USA) 2 1 2 2 paurosomus Pritchard, 1935 (Mexico) 2 2 2 2 senilis (Bigot, 1878) (USA) 2 1 2 2 Palaearctic lugubris Hermann, 1906 (Afghanistan) 2 2 2 2 palestinensis Theodor, 1980 (Israel) 2 2 2 2 Afrotropical peregrinus Engel, 1929 (South Africa) 2 2 2 2 2 2 Holopogon Nearctic atrifrons Cole, 1924 (USA) 2 2 2 2 1 caesariatus Martin, 1959 (USA) 2 2 2 2 1 currani Martin, 1959 (USA) 2 2 2 2 1 ? oriens Martin, 1959 (Canada) 2 2 2 2 1 sapphirus Martin, 1967 (USA) 2 2 2 2 2 seniculus Loew, 1866 (USA) 2 2 2 2 1 ? vockerothi Martin, 1959 (Canada) 2 2 2 2 I 'sp. n. 3' (as labelled) (Mexico) 2 2 2 2 2 Palaearctic cornutus Theodor, 1980 (Israel) 2 2 2 2 dimidiatus (Meigen, 1820) (Moravia) 2 2 2 2 Jumipennis (Meigen, 1820) (Germany) 2 2 2 2 nigripennis * (Meigen, 1829) (Germany) 2 2 2 2 priscus (Meigen, 1920) (Turkey) 2 2 2 2 Afrotropical Jugax Loew, 1858 (South Africa) 2 2 2 2 2 2 2 tomentosus Oldroyd, 1974 (South Africa) 2 2 2 2 2 2 2 vumba Oldroyd, 1974 (Zimbabwe) 2 2 2 2 2 2 2 A- Face moderately and evenly protuberant, particularly in upper part = 1; more of less flat = 2. B- Mystax with macrosetae = 1; with fine setae only = 2. C- Plumose setae present (mainly prothorax & occiput) = 1; absent = 2. 0- Postpronotallobe with macro setae (as well as fine setae) = 1; without macrosetae (only fine setae) = 2. E- Disc of scutellum with fine setae (sometimes sparse, or absent in males of a few Holopogon species in which the females have setae) = 1; setae absent = 2. F- Costa continues around anal lobe = 1; stops where vein A, meets wing margin = 2. G- Cell cup closed and stalked = 1; open at wing margin = 2. H- Hind tibia greatly enlarged (as thick as femur) = 1; of more usual proportions = 2. LONDT: AFROTROPICAL ASILIDAE 24 63 MATERIALS AND METHODS Materials and methods concur with my previous work (see Londt 1992) and do not need detailed specification here. Although male terminalia may be rotated, illustrations were prepared ignoring rotation (ie. the epandrium is shown as dorsally situated). All material consulted is in the Natal Museum, unless otherwise stated. Afroholopogon gen. n. Cyrtopogon Loew, 1847: 516 (as subgenus of Dasypogon). Type-species: Asilus ruficomis Fabricius, 1794, by designation of Rondani (1856: 157). [Afrotropical species only]. Heteropogon Loew, 1847: 488 (as subgenus of Dasypogon). Type-species: Dasypogon manicatus Meigen, 1820, by designation of Back (1909: 318). [Afrotropical species only]. Holopogon Loew, 1847: 473 (as subgenus of Dasypogon). Type-species: Dasypogon nigripennis Meigen, 1820, by designation of Coquillett (1910: 522). [Afrotropical species only]. Type species: Holopogon vumba Oldroyd, 1974. Description: Medium-sized, Holopogon-like asilids with generally dark red-brown to black facies, and the following combination of characters: Head (Figs 1-2): clearly wider than high in anterior view. Antenna: scape ca as long as pedicel, segment 3 ca 1.5 times as long as scape and pedicel combined, style narrow, elongate (ca as long as scape and pedicel combined), clearly 2-segmented, with terminal spine-like seta. Face flat to slightly protuberant in lower part; mystax composed of more or less uniformly thin setae, occupies almost entire face; occipital and adjacent setae not plumose. Palpi well developed, 2-segmented; proboscis of moderate length, straight, fairly stout and with almost circular cross-section. Thorax: prothorax and adjacent setae not plumose; postpronotal lobe largely bare, setae thin (no stout macrosetae present); anepimeral bristle absent; scutellar setae thin and not extending onto disc; postmetacoxal area membranous. Wing (Fig. 3): transparent or uniformly smoky brown, without dark markings, uniform microtrichial cover, C extends around wing margin only as far as vein Al with which it merges, cell m) open, cup closed and stalked. Legs: metathoracic tibia somewhat enlarged distally, but not larger in diameter than femur (Fig. 4); pulvilli and empodia well developed. Abdomen: d terminalia slightly, if at all, rotated; d epandrium of moderate length, lobes entirely separate or narrowly fused at base; hypandrium well developed, and with elongate, somewhat up-turned and dorsoventrally compressed, distal process. Etymology: Gr. Afro - pertaining to the Afrotropical region + Holopogon (refers to the distribution of this Holopogon-like taxon). Relationships: Afroholopogon is separated from all other Afrotropical Stenopogoninae by the possession of the following combination of characters: anatergites bare; anal lobe and alula lacking a bordering vein marginally; pulvilli well developed; postmetacoxa] bridge absent. Rhabdogaster Loew, 1858 is most similar to Afroholopogon, but can be immediately recognised by the presence of a postmetacoxal bridge. A key to the stenopogonine genera is in preparation and will be published shortly. New combinations: Although there is no complete review of Afrotropical species previously assigned to Cyrtopogon, Heteropogon and Holopogon, I have seen the types of nine of the twelve species and can confirm that they are congeneric. From 64 ANNALS OF THE NATAL MUSEUM, VOL. 35 1994 published descriptions, the three not seen (fugax, gracilis and niveoscutum) appear also to be congeneric. In the interests of taxonomic stability, and pending revisionary work, I hereby place all known species (as listed by Oldroyd 1980) in new combination with Afroholopogon as follows: africanus Ricardo, 1925: 275 (Cyrtopogon). South Africa; Namibia. capensis Lindner, 1961: 6 (Heteropogon). South Africa. flavidus Lindner, 1973: 77 (Heteropogon). Namibia. fugax Loew, 1858: 350 [1860: 166] (Holopogon). South Africa. gracilis Engel & Cuthbertson, 1937: 13 (Heteropogon). Zimbabwe; ? Namibia. holocephaloides Lindner, 1955: 30 (Heteropogon). Tanzania. niveoscutum Hull, 1967: 239 (Holopogon). Lesotho. oldroydi Lindner, 1973: 78 (Heteropogon). Namibia. peregrinus Engel, 1929: 168 (Heteropogon). South Africa. tomentosus Oldroyd, 1974: 49 (Holopogon). South Africa. vumba Oldroyd, 1974: 47 (Holopogon). Zimbabwe. waltlii Meigen, 1838: 71 (Dasypogon). Spain; ? Zimbabwe. waltli. Incorrect subsequent spelling of waltlii. DISCUSSION Morphological details provided in the generic diagnosis and Table 2 indicate that Palaearctic and Nearctic representatives of Cyrtopogon, Heteropogon and Holopogon appear to be congeneric, and that these three genera are valid Holarctic taxa. Afrotropical species previously assigned to these genera are, however, digeneric (ie. not congeneric - Londt 1993), and should be combined in a single genus-group taxon. One of the most important differences is the manner in which the costal vein merges with Al in Afroholopogon, the anal lobe consequently lacking a bordering vein. All representatives studied of Loew's three genera have the anal lobe entirely bordered by the costa. Afroholopogon is not unique among Afrotropical stenopogonine genera in terms of this character. Rhabdogaster Loew, Acnephalum Macquart and Ammodaimon Londt, have the same arrangement. The closed and stalked condition of cell cup in the Afrotropical species appears to be directly related to the way C fuses with AI' while the condition seen in Holopogon, where C continues around the anal lobe, is more likely the result of a narrowing of cup and resultant distal fusion of CuA and Al (note that two Nearctic species have cell cup 2 open (Table 2); the taxonomic significance of this is not known). The more important apomorphies used to characterise Cyrtopogon (protuberant face, almost total absence of body macrosetae), Heteropogon (plumose setae) and Holopogon (enlarged hind tibiae, closed cup resulting from fusion of CuA and A) 2 (Wood 1981), are uniformly absent in Afroholopogon (although cup is closed as explained above). The significance of morphological features of the male genitalia cannot be fully appreciated without a detailed study of many species. Detailed examination of male examples of the genotypes of Cyrtopogon (c. ruficomis) and Holopogon (H.nigripennis), and, in the absence of the genotype of Heteropogon (H. manicatus), LONDT: AFROTROPICAL ASIUDAE 24 65 Figs 1--4. Afroholopogon vumba (Oldroyd). 1-2. Head. I. Lateral. 2. Anterior. 3. Wing. 4. Metathoracic leg. Scale lines = I nun. another Palaearctic Heteropogon (H. lugubris) was, however, undertaken (Figs 5-13). Although much Afrotropical material exists in the Natal Museum, few specifically identified specimens were available for comparison. Although type matelial of Cyrtopogon africanus, borrowed from The Natural History Museum, 66 ANNALS OF THE NATAL MUSEUM, VOL. 351994 11 Figs 5-13. Male genitalia. 5-7. Cyrtopogon ruficornis (Fabricius). 5. Dorsal. 6. Lateral. 7. Ventral. 8-10. Heteropogon lugubris Hermann. 8. Dorsal. 9. Lateral. 10. Ventral. 11-13. Holopogon nigripennis (Meigen). II. Dorsal. 12. Lateral. 13. Ventral. Scale lines = 1 mm. London, was female, very similar, although probably dispecific (ie, not conspecific - Londt 1993), male material from the Cape Province (33 kIn N Op Die Berg), South Africa, was found in the Natal Museum collection (Figs 14-16). The only identified Afrotropical Heteropogon species in the Natal Museum is H. peregrinus. Several specimens were labelled by Harold Oldroyd in 1972 prior to his published work on South African asilids (Oldroyd 1974). As this group is still to be revised, I lack confidence in this identification (as did Oldroyd who included a question mark on a few of his labels). Despite this, I present illustrations of the male genitalia (Figs 17-19) of one of these specimens (Willowmore, Cape Province, South Africa), The only identified Natal Museum Holopogon, also labelled by Oldroyd in 1972, are H. LONDT: AFROTROPICAL ASILIDAE 24 67 fugax, tomentosus (types) and vumba (types). I present illustrations of the male genitalia of fugax (Figs 20-22) and vumba (Figs 23-25) (there being only a single male, the holotype, of tomentosus). 16 Figs 14-25. Afroholopogon male genitalia. 14-16. 'Op Die Berg' cJ close to cJ paratype of A. africanus (Ricardo) (previously asigned to Cyrtopogon). 14. Dorsal. 15. Lateral. 16. Ventral. 17-19. A. peregrinus (Engel) (previously Heteropogon). 17. Dorsal. 18. Lateral. 19. Ventral. 20-23. A. fugax (Loew) (previously Holopogon). 20. Dorsal. 21. Lateral. 22. Ventral. 23-25. A. vumba (Oldroyd) (previously Holopogon). 23. Dorsal. 24. Lateral. 25. Ventral. Scale lines = 1 mm. 68 ANNALS OF THE NATAL MUSEUM. VOL. 35 1994 A superficial examination of males of all species of Holarctic Cyrtopogon examined (Table 2) revealed a consistency of genital form (although specific differences certainly occur) which further convinces me that all these species are congeneric. The same appears to be true of Holarctic Heteropogon and Holopogon, adding further confidence to my belief that these are valid genera and that the Palaearctic and Nearctic representatives are congeneric. Examination of males of Afrotropical species previously assigned to these three genera reveal a genital form not consistent with any of them, but reasonably consistent with each other. The main characteristics of the Afrotropical taxa are: i. The epandrium is divided into two lobes (may be fused narrowly at base) (like Cyrtopogon and Holopogon, but unlike Heteropogon). ii. Gonocoxites have a well-developed dorsodistal lobe (in lateral aspect) and a smaller more ventrally situated lobe or bump (of variable size); a condition not entirely comparable with the northern hemisphere genera. iii. The hypandrium is usually large and extended distally as a well-developed, often dorsoventrally compressed, and upwardly curved, process. This hypandrial form is somewhat different to that found in the three northern hemisphere genera. Although Afroholopogon is a fully justified generic concept on the morphological evidence presented, the proper grouping of the many Afrotropical species (a number of undescribed species certainly exist) will have to await revisionary study. Field experience suggests that distinct species groups may well exist within Afroholopogon. Many of the smaller, dark species (formerly loosely thought of as Holopogon) are mostly found resting on large rocks, boulders or rocky cliff tops and faces. The larger, perhaps more slender, species (previously thought of as Heteropogon) appear to inhabit mixed grassland habitats (often on the tops of ridges or on hillsides in the western Cape, or adjacent to forests in Natal, Transvaal and Zimbabwe). Examples of a species closely resembling Cyrtopogon africanus (the largest and most robust of the species now included in Afroholopogon) have been observed flying between flowering, sedge-like plants in an arid, sandy area of the southwestern Cape Province of South Africa. Judging by published information, and locality data attached to the many specimens in the Natal Museum, the distribution of Afroholopogon is centred in southern Africa. The genus appears to be concentrated mainly in the southwestern Cape Province (most specimens have been collected in this subregion), but examples are known from the drier Karoo areas of the western Cape (eg. inland areas of Calvinia and Nieuwoudtville) and the Richtersveld. Species have also been collected in the southern and eastern Cape, Natal, and both the eastern and western Transvaal. A single species has been recorded from Lesotho, three from Zimbabwe and one from Tanzania. Three or four species have been recorded from Namibia (there are many Natal Museum specimens, from a variety of localities). I have also seen specimens from eastern Botswana. ACKNOWLEDGEMENTS My thanks are extended to all those who have, over many years, sent me the non Afrotropical asilid material used in this paper for comparative purposes. Among these people are Dr E. Fisher (USA), Dr M. Hradsky (Czechoslovakia), Mr R. LONDT: AFROTROPICAL ASILIDAE 24 69 Cannings (Canada) and Dr A. Friedberg (Israel). I thank my colleagues Dr D. Barraclough, Dr B. Stuckenberg and Mr A. Whittington for commenting on the manuscript. The Foundation for Research Development provided a grant in support of my work on Afrotropical Asilidae. REFERENCES DANIELS, G. 1989.37. Family Asilidae. 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