A Revision of Afrotropical Quasimodo Flies (Diptera: Schizophora; Curtonotidae). Part III — the Malagasy Species of Curtonotum Macquart, with Descriptions of Six New Species

ABSTRACT The Madagascan fauna of the genus Curtonotum Macquart, 1844 is reviewed. Type material of the seven species described by Tsacas in 1974 (C. balachowskyi, C. boeny, C. keiseri, C. pauliani, C. sakalava, C. sternithrix and C. stuckenbergi) was studied and additional material of five of these is noted, substantially increasing their known distributions. Six of the seven species described by Tsacas are endemic to Madagascar; unpublished records indicate, however, that C. pauliani, occurs in Namibia and South Africa on the African continental mainland. Six additional endemic species are described as new: C. coronaeformis sp. n., C. gladiiformis sp. n., C. griveaudi sp. n., C. irwini sp. n., C. parkeri sp. n., and C. rinhatinana sp. n. The head and thorax, frons, wing, sixth sternite and hypandrium of the male of the 13 species are illustrated for the first time, as well as the highly diagnostic male phallus, both laterally and dorsally at the junction of the basiphallus and distiphallus. A key to species based on male characters is provided, and species distributions are mapped and interpreted. The biogeographical significance of the Madagascan species is discussed. An annotated checklist of Madagascan Curtonotidae is presented, and co-ordinates used to plot maps and a list of vegetation types in which species occur are provided.


INTRODUCTION
Four genera of Curtonotidae are currently known worldwide, i.e., Axinota van der Wulp, 1886, Cyrtona s.l. Séguy, 1938, Tigrisomyia Kirk-Spriggs, 2010and Curtonotum Macquart, 1844, all of which occur in the continental Afrotropical Region; Tigrisomyia exclusively so. Curtonotum is the most speciose genus and is found in all zoogeographical regions of the world except Australasia/Oceania and Antarctica, although Klymko and Marshall (2011) point out that Curtonotum in its current broad sense is paraphyletic with respect to Axinota, and suggest restricting the name Curtonotum to a monophyletic New World group. Two genera are known to occur on Madagascar, Axinota, represented by a single species, A. kyphosis Kirk-Spriggs, 2010, of supposed Oriental origin and Curtonotum (Appendix I). Notably, the genus Cyrtona s.l., which is extremely species-rich in the continental Afrotropical Region, is apparently absent.
The Curtonotum fauna of Madagascar has remained a neglected group and nothing is currently known of their biology and immature stages. Species in the continental Afrotropical Region are known to roost in the burrows of small mammals, hollow trees and overhangs of riverbeds, etc. (e.g., Kirk-Spriggs 2008b;Meier et al. 1997;Tsacas 1977) and, at least in the case of species occurring in xeric regions, are known to develop as scavengers in the damaged egg pods of locusts and grasshoppers (Orthoptera) (Greathead 1958;Kirk-Spriggs 2008b;Meier et al. 1997). A more complete review of the known biology of the genus will be presented in Part IV of this revision. (Figs 1-26), were prepared from images captured with a ® Leica EZ4HD stereo microscope with built-in digital camera. These were photographed using a ring light and dome (Kerr et al. 2008) in a range of focal planes and were digitized using ® Combine ZP Image Stacking Software.

Figures of the head, thorax and frons
Wings were detached and placed between two glass slides. Images (37)(38)(39) were captured with a ® Leica Wild M3Z binocular microscope with ® Nikon E5400 digital camera attached. Fig. 36 was prepared using the ® Leica EZ4HD microscope.
Male terminalia were mounted laterally or dorsally, in a blob of heated and then a ® Leica Wild M3Z binocular microscope with a camera lucida attachment. Images were enlarged and traced, and details added by hand in pen and ink by constant referral to the specimen. Scale bars were added using a 0.5 mm graticule slide.

Measurements
Measurements were taken with a graticule eye piece on a ® Leica Wild M3Z binocular microscope, calibrated with a 0.5 mm graticule slide.
As the descriptions and redescriptions are based on the holotype in most cases, measurements are provided for the holotype only. In some cases overall lengths of series of specimens were taken prior to dissection and in such cases a range of lengths is provided. In some cases overall lengths could not be provided as specimens were dissected beforehand. In such cases the measurements provided by Tsacas (1974) are 394 AFRICAN INVERTEBRATES, VOL. 52 (2), 2011 included (where applicable), or combined length of the head and thorax and thorax and scutellum alone are provided. Tsacas did not specify how his measurements were made, but overall length measurements appear to have included the wings (i.e., measured from the head to the tips of the wings), rather than the combined lengths of the head, thorax and abdomen, so are larger by comparison with the measurements provided here.
Overall length was measured from the anteriormost point of the frons to the tip of the abdomen (viewed laterally). Length of head and thorax combined was measured from the anteriormost point of the frons to the scutoscutellar suture (viewed dorsally).
Length of thorax and scutellum combined was measured from the anterior margin of the mesonotum (immediately posterior to head) to the anterior tip of the scutellum (viewed dorsally).
The eye height/length ratio was measured from the most ventral to the most dorsal point of the eye and through the eye medially (viewed laterally).
Genal height was measured immediately below the ventromedial part of the eye (viewed laterally).
Frons length represents the distance between the ventral margin (immediately above the point of antennal insertion), to the posterior ocelli (viewed dorsally). Frons width represents the distance between the lateral margins of the frons, measured at the midpoint between the posterior ocelli and the ventral margin of the frons.
Length of the wing was measured from the humeral crossvein (Fig. 27,h) to the apex of the second radial vein (Fig. 27, R 4+5 ).

Descriptions
A full redescription is provided for C. balachowskyi Tsacas, the most widely distributed species of the genus in Madagascar. Redescriptions and descriptions of other species are compared to this and differences and additional characters noted only. A full description or redescription of the male terminalia is provided in all cases.

Distribution maps
Each set of specimen locality co-ordinates listed in Appendix II was obtained in one of two ways: (a) original co-ordinates provided on data labels, later converted to decimal co-ordinates; or (b) obtained from Internet geo-referencing websites powered by Google Earth™.
Distribution maps were prepared by converting the list of geographic co-ordinates indicating the point location of specimen records into a spatial data layer in ArcMap 9.3. The specimen location layer was overlaid on the Vegetation Map of Madagascar by Moat and Smith (2007). Plotted points are based on material examined as part of the Vegetation types cited in the text follow Moat and Smith (2007), as listed in Appendix II, biomes follow Yoder and Nowak (2006) (Fig. 105), biogeographical zones Boumans et al. (2007) and Wilmé et al. (2006) (Fig. 106) and bioclimatic zones Cornet (1974) and Schatz (2000) (Fig. 107).
Differential diagnosis: This species differs from other species occurring on Madagascar in having the medial lobes of the hypandrium (viewed dorsally), parallel-sided, with a narrow medial membranous area clothed in tiny spinules. Interpretaton of its relationships to other species occurring in the Afrotropical Region must await the outsome of phylogenetic study. Redescription:

Male
Measurements: Overall length 2.8-4.8 mm (n = 47, N-T); length of head and thorax combined 2.8 mm; length of thorax and scutellum combined 2.9 mm; wing 4 mm long.
Head (Figs 7,20). Compound eye probably green-brown iridescent in living examples, orly, eye height/length ratio: 12:7 (HT); frons (Fig. 20) subparallel-sided, slightly wider than long, frons length/width ratio: 7:85 (HT), very slightly wider at vertex than at ventral margin, ground colour pale dirty yellow, faintly darker towards vertex and between orbital plates, otherwise both vittae inconspicuous, surface with a few minute pale to dark brown setulae, positioned at medial margin of orbital plates; orbital plates and ocellar triangle silver-grey pruinose; ocelli clear grey with 4 or 5 minute dark setulae arranged in two closely-approximated regular rows between posterior ocelli; orbital plates extending from vertex of head to 0.9 length of frons, slightly indented at lateral margin between posterior and anterior orbital setae; lateral margins with narrow orbital seta moderately strong, slightly outcurved, shorter than outer vertical seta, with tiny proclinate medial orbital seta inserted anteromedially to socket of posterior orbital seta; anterior orbital seta moderately strong, ca half length of ocellar setae; ocellar setae postocellar setae strong, cruciate, slightly shorter than outer vertical seta; antennal scape pedicel basally, darkened apically, silver-grey pruinose as in face, longer than wide, apex bluntly-pointed, arista with 9-11 long dorsal branches and 3 or 4 ventral branches in addition to terminal fork; lunule and face uniform silver-grey pruinose throughout, low ridge, extending half length of face, pre-epistomal line indented; clypeus brown, especially laterally; 1 pair fairly strong vibrissae inserted on posterior lateral margin moderately strong, black postocular setae; gena narrow, eye height/genal height ratio: 12:1 (HT), silver pruinose, abruptly dirty brown beyond basal angle; palpus blackbrown, brown microtrichose. Thorax with multiple rows of regular, short, black, overlapping setulae; silver-grey pruinose, with four parallel chestnut-brown pruinose vittae on dorsal surface, 2 median vittae extending from anterior margin to region of anterior dorsocentral seta socket, 2 lateral 2 pairs of dorsocentral setae, posterior long and strong (shorter than lateral scutellar acrostichal setae shorter than anterior dorsocentral seta; presutural seta moderately strong, reclinate, as long and strong as posterior notopleural seta; 2 notopleural setae the anterior slightly longer than posterior; 1 strong, reclinate supra-alar seta slightly exceeding length of posterior dorsocentral seta; 2 reclinate postalar seta moderately strong, same size as acrostichal setae; postpronotum dirty yellow-grey pruinose, with 2 strong postpronotal setae, the more dorsal longer and reclinate, the more ventral pruinose with 3 moderately strong anepisternal setae, the dorsal and medial reclinate, stronger and of equal length, the more ventral shorter, slightly dorsally-directed, surgroups of 3; anepimeron, laterotergite and meron silver-grey pruinose, glabrous; katepisternum silver-grey pruinose, with 2 katepisternal setae, the more ventral strong, ca 0.2 length of rior margin. Scutellum. Silver-grey pruinose as in mesonotum, with faint medial brown pruinose vitta basally (under some lights); anterior 0.8 clothed in black, irregular, overlapping setulae; 2 pairs of strong scutellar setae, 1 weak basal scutellar setula and 1 weak intermediate scutellar setula, the latter inserted closer to lateral than medial scutellar setae (0.8 distance between medial and lateral scutellar setae).
Legs. Fore coxa silver-yellow pruinose with two moderately strong, brown, ventrallyon anterior surface; mid and hind coxa yellow-grey pruinose, mid coxa with 2 very brown setulae; hind coxa with 1 weaker lateral black seta and 1 brown setula; femora, tibia and tarsi uniform dirty yellow; all tibiae with preapical seta; fore tibia with 4 strong setae on lateral margin, the second basal seta shorter than other three, with cte-nidium of 10-12 short, sharp, black spinules, separated from each other by one or more basal spinule widths. Wing (Fig. 33). Long, relatively narrow, tip evenly-rounded, veins chestnut-brown, membrane very faintly infuscate brown throughout, very slightly darker in r 1 and anterior half of r 2+3 and in region of dm-cu crossvein; costa with prominent costal spines in basal 0.8 from costal break; R 4+5 slightly anteriorly-produced in basal third, R 2+3 and R 4+5 subparallel, r 2+3 expanded apically; dm-cu crossvein slightly obliquely angled posteriorly, evenly curved medially; cua 1 relatively long and narrow; A 1 +CuA 2 and A 2 manifested as a fold only; A 2 extending half length of cua 1 ; haltere dirty yellow.

Curtonotum boeny
Differential diagnosis: This species is closely related to C. griveaudi sp. n., differing in the colour of the frons and antennae, the shape of the wing and the shape of the male terminalia. Both share the peculiar subtriangular form of the epandrium with the lateral setation reduced to two long and strong setae originating from the blunt point formed by the ventral margin. Curtonotum boeny differs from C. griveaudi sp. n., however, in having the hypandrial arm narrowed apically, the surstylus shorter and wider basally, the presence and position of the conspicuous internal bulge on the they occur sympatrically. Redescription:
Thorax nut-brown pruinose vittae on dorsal surface, extending from anterior margin to region than medial scutellar seta; reclinate supra-alar seta, slightly shorter than posterior dorsocentral seta; thoracic pleurae silver-grey, yellow pruinose in their centres; postthe 5 larger grouped together at posterodorsal margin; katepisternum with dorsal katepisternal seta ca 0.3 length of ventral katepisternal seta, with base and along posterior margin. Scutellum. As in mesonotum; two pairs of strong scutellar setae, 1 weak basal scutellar setula and 1 weak intermediate scutellar setula, the latter inserted equidistant between lateral and medial scutellar setae.
Terminalia (Figs 46,49,52). Hypandrium (Fig. 46, hy broad-based, rounded-truncate dorsobasal lobe, posterior bridge dorsally and ventrally with 2 setulae proximal to postgonite, the more lateral ventrally directed, the medial ventromedially directed (obscured by epandrium on Fig. 46), sclerotised area of medial 405 lobes (viewed dorsally), with slightly rounded margins, not overlapping (not convex); postgonite (Fig. 46,pg) long, thin and straight; epandrium (Fig. 46, ep) subtriangular (in lateral view), with deep, oblique excavation along ventral margin, ventral lobe forming a blunt point from which two very strong, long setae originate; cercus (Fig. 46, ce) not prominent, longest setae as long as medium setae on dorsal margin of epandrium; surstylus (Fig. 46,ss phallus (as in Figs 49,ph,bp,dp;52,bp, dp) C-shaped, moderately sclerotised, brown; bp) broader in basal half, slightly narrowed in apical half, with large, conspicuous bp) moderately dp) long, with slight curve at midlength, very narrow (viewed laterally and dorsally). Variation: The frons appears slightly darker in ex-alcohol specimens.  Figs 6,19,32,66,69,72,83,97 Etymology: From Latin corona (crown) and formis (in the form of), and refers to the crown-like lateral extension of the distiphallus of this species. Differential diagnosis: This species is closely related to C. parkeri sp. n.; the shape, maculae and setation of abdominal sternites 4 and 5 are virtually identical, the apical region of the basiphallus is markedly expanded in both species, with very similar left and right raised keels and both share the raised and spinose right sclerotised area of the basiphallus. In C. coronaeformis sp. n., however, the basiphallus is less markedly narrowed medially and less expanded in the apical third, and the raised and spinose right sclerotised area of the distiphallus is conspicuously developed, with a series of regular to irregular spines. The two species occur sympatrically. Description: Male (primarily based on ex spirit-preserved HT).
As redescribed for C. balachowskyi, differing in the following respects: Measurements: Overall length unknown; length of head and thorax combined 2.9 mm; length of thorax and scutellum combined 2.4 mm; wing length 3.7 mm.
Legs. Fore coxa with 22 brown setulae on anterior surface; fore tibia with ctenidium of 10 or 11 short, sharp black spinules.
Wing (as in Fig. 32). Veins chestnut-brown, membrane very faintly infuscate brown throughout, very slightly darker in r 1 and in region of dm-cu crossvein; dm-cu crossvein oblique, in shape of uninterrupted arc.
Abdomen merging with large, concolourous T-shaped dorsolateral maculae; lateral margin of posterior and lateral margins evenly rounded, apical margin straight; sternite 5 rectangular, similarly shaped to sternite 4, slightly longer and wider medially, with 2 small setulae arranged in irregular rows, those along lateral margins longer and stronger; sternite 6 ( Fig. 83) narrowed basally, evenly rounded laterally (may appear narrower than Fig. 83 in undissected specimens), with broad, deep apical excision and brown maculae medially and fascia laterally, merging apically, clothed in long, black, irregular, medially-directed, brown setulae in apical 0.8, those at apical margin longer and more prominent.
Terminalia (Figs 66,69,72). Hypandrium (Fig. 66, hy) long, with broad-based rounded-truncate dorsobasal lobe, posterior bridge dorsally and ventrally produced laterally), with 2 setulae proximal to postgonite, the more lateral ventrally directed, the medial ventromedially directed (obscured by epandrium on Fig. 66), sclerotised area of medial lobes (viewed dorsally), with margins evenly rounded, convex, closely abutting, not overlapping; postgonite ( margin slightly angled, ventral margin with extensive row of long, regular to irregular, apically-directed setae; cercus ( Fig. 66, ce) not prominent, longest setae longer than setae on dorsal margin of epandrium; surstylus ( Fig. 66, ss) long and narrow, slightly ph, bp, dp, 72, bp, dp) C-shaped, moderately sclerotised, brown; phallapodeme ( Figs 8,21,34,41,43,45,85,99 Etymology: From Latin gladius (sword) and formis (in the form of), and refers to the sword-like shape of the distiphallus of this species. Differential diagnosis: This species is probably most closely related to C. balachowskyi Tsacas. Both share the similarly-shaped scimitar-like distiphallus, with the incurved basal area (viewed laterally) and the subquadrate sternite 6, with a very shallow apical excision. Curtonotum gladiiformis differs from C. balachowskyi, however, in having the lateral margin of the apical border of the basiphallus developed into a medial and submedial spine, as opposed to C. balachowskyi, in which the right lateral border forms a distinct, angulate fold, and in having the setae on sternite 6 much longer on the apical margin. Description: Male (primarily based on ex spirit-preserved HT).
as in Fig. 43 and this may be the result of slight distortion in phallus of the HT.  Figs 11,24,37,47,50,53,89,102 Etymology: The species is named in honour of Paul Elexis Jacques Griveaud , in recognition of his contribution to Madagascan entomology. Differential diagnosis: This species is closely related to C. boeny, differing in the colour of the frons and antennae, the shape of the wing and the shape of the male terminalia. Both share the peculiar subtriangular form of the epandrium, with the lateral setation reduced to two long, strong setae originating from the blunt point formed by the ventral margin. Curtonotum griveaudi sp. n. differs from C. boeny, however, in having the hypandrial arm much broader apically and the surstylus considerably longer and narrower basally. The species further differ in the presence and position of the low internal bulge of the phallus, with the basal section of the phallus quite straight, and the apical shape of the basiphallus, with its reduced lateral keel and short, spine-like whether they occur sympatrically. Description: Male (primarily based on ex spirit-preserved HT).
As redescribed for C. balachowskyi, differing in the following respects: Measurements: Overall length unknown; length of head and thorax combined 2.2 mm; length of thorax and scutellum combined 2.2 mm (HT); wing length 3.5 mm (n = 1, N-T).
Wing (as in Fig. 37). Veins brown, membrane hyaline with very faint brown infuscation, very slightly darker in posterior half of r 1 and anterior half of r 2+3 and in region of dm-cu crossvein; dm-cu crossvein strongly, obliquely angled in even arc.
Terminalia (Figs 47,50,53). Hypandrium (Fig. 47, hy) long, with broad-based rounded-truncate dorsobasal lobe, posterior bridge dorsally and ventrally produced rally-directed arc (viewed laterally), setulae absent, sclerotised area of medial lobes 415 (viewed dorsally), with slightly rounded margins, not overlapping (not convex); postgonite (Fig. 47, pg) long, thin and straight; epandrium (Fig. 47, ep) subtriangular (in lateral view), with deep, oblique semicircular excavation along ventral margin, ventral lobe forming a blunt point, from which two very strong, long setae originate; cercus (Fig. 47, ce) not prominent, longest setae as long as medium setae on dorsal mar- gin of epandrium; surstylus (Fig. 47, ss) drawn out, very long and narrow, slightly wider basally and curved in apical 0.8; phallus (as in Figs 50, ph, bp, dp, 53, bp, dp) C-shaped, weakly sclerotised, pale brown; phallapodeme (Fig. 50,ph) fused to basiea apodeme and basiphallus; basiphallus (Fig. 50, bp) broad and straight in basal half, second bend); apical section ( Fig. 53, bp) very broad, right margin laterally expanded and evenly rounded, with slightly raised margin, left lateral margin with distinct raised fold, 53, dp) long, evenly curved, scimitar-like (viewed laterally), narrow (viewed dorsally). Variation: The frons is darker in some specimens, almost chestnut-brown; even in specimens with a paler brown frons the two longitudinal brown vittae are strikingly apparent.  Figs 4,17,30,64,67,70,81,95 Etymology: The species is named in honour of Michael Edward Irwin, in recognition of his contribution to our knowledge of Madagascan Diptera. Differential diagnosis: This species is probably most closely related to C. parkeri sp. n. and C. coronaeformis sp. n. All share the extensively-developed sclerotised area of the distiphallus and sternite 6 is very similar in all three species. It differs from C. parkeri and C. coronaeformis, however, in lacking a raised lateral, spinose ridge on the distiphallus and in having the right lateral margin of the basiphallus developed into a long, curved, ventrally-directed spine, with smaller spine medially. Male (primarily based on ex spirit-preserved HT).
Wing (as in Fig. 30). Veins chestnut-brown, membrane very faintly infuscate brown throughout, very slightly darker in region of dm-cu crossvein; dm-cu crossvein acutely angled with interrupted arc; haltere dirty white.
Variation: The length of the larger, curved ventrally-directed spine of the distiphallus is variable in some specimens. Other terminalia characters are constant and this is here Curtonotum keiseri Tsacas, 1974 Figs 1, 14, 27, 55, 58, 61, 79, 92 Curtonotum keiseri Differential diagnosis: This species is closely related to C. stuckenbergi Tsacas, differing in the colour of the frons (brown with distinct vittae in C. keiseri and yellow with indistinct vittae in C. stuckenbergi of the male terminalia. Both share the deep brown, infuscate wing membrane, the dove-tailed sternite 6, and the straight, ventrally-directed, lateral spine and two smaller spines on the distiphallus. Curtonotum keiseri differ from C. stuckenbergi, however, in the angle and degree of curvature of the dm-cu crossvein of the wing, in the lateral margins of the phallus being only moderately sclerotised, and in the smaller spines of the distiphallus positioned in the basolateral region, rather than the left and right lateral regions. The ranges of the two species do not overlap, and they occur allopatrically. Redescription:

Male
As redescribed for C. balachowskyi, differing in the following respects: Measurements: Total length 5 mm; length of head and thorax combined 3 mm; length of thorax and scutellum combined 3 mm (n = 1, PT); wing length 3.8 mm (n = 1, N-T).
Scutellum. As described for C. gladiiformis sp. n.
Wing (as in Fig. 27). Long and broad, tip evenly-rounded, veins chestnut-brown, membrane deep-brown infuscate throughout, darker in r 1 and anterior half of r 2+3 and in region of dm-cu crossvein; dm-cu crossvein with even arc dorsally; haltere dirty yellow.
Terminalia (Figs 55, 58, 61). Hypandrium (Fig. 55, hy) long, with broad-based rounded-truncate dorsobasal lobe, posterior bridge dorsally and ventrally produced (sublaterally), with 2 parallel setulae proximal to postgonite, of similar length (obscured by epandrium on Fig. 55), sclerotised area of medial lobes (viewed dorsally), with margins evenly rounded, convex medially, closely abutting, overlapping; postgonite (Fig.  55, pg) long, thin and straight, with slight undulating anterior margin; epandrium (Fig.  55, ep) slightly broader dorsally than ventrally (viewed laterally), evenly rounded on dorsal margin, posterior margin slightly angled, ventral margin with extensive row of long, regular to irregular, apically-directed setae; cercus (Fig. 55, ce) not prominent, longest setae longer than setae on dorsal margin of epandrium; surstylus (Fig. 55, ss) ph, bp, dp, 61, bp, dp) C-shaped, moderately sclerotised, brown; phallapodeme (Fig. 58, ph) fused to basiphallus, subtriangular (viewed laterally), with basal margin developed into two ea of phallapodeme and basiphallus (missing from specimens illustrated in Fig. 58); ba-  (Fig. 58, bp apex, markedly narrowed in apical third (viewed dorsally); apical section (Figs 58, 61, bp) broad basally, sclerotised area extensive, abruptly narrowed towards apex, basal section with membranous window, with one narrow, but strong, straight, ventrally directed lateral spine (arrowed on Fig. 61) and two smaller spines, positioned in basolateral region, left margin of sclerotised area with irregular row of small tubules. sp. n. Figs 5,18,31,65,68,71,82,96 Etymology: The species is named in honour of Frank Parker, in recognition of his contribution to our knowledge of Madagascan Hymenoptera. Differential diagnosis: This species is closely related to C. coronaeformis sp. n.; the shape, maculae and setation of abdominal sternites 4 and 5 are virtually identical, the apical region of the basiphallus is markedly expanded in both species, with very similar left and right raised keels, and both share the raised and spinose right sclerotised area of the basiphallus. In C. parkeri sp. n., however, the basiphallus is more markedly narrower medially and expanded in the apical third, and the raised and spinose right sclerotised area of the distiphallus is less conspicuously developed, with three short, dark-tipped spinules. The two species occur sympatrically.

Description:
Male (primarily based on ex spirit-preserved HT).
As redescribed for C. balachowskyi, differing in the following respects: Measurements: Overall length 3.65-4.4 mm (n = 4, PT); length of head and thorax combined 2.8 mm; length of thorax and scutellum combined 2.3 mm; wing length 4.1 mm (HT).

Scutellum.
As described for C. gladiiformis sp. n.
Differential diagnosis: This species is most closely related to C. cuthbertsoni and to a complex of seven, as yet undescribed species, all occurring in the continental Afrotropical Region. All possess one or more basomedial spines on the dorsal margin of the distiphallus. The Madagascan species, C. sakalava Tsacas, which has a conspicuous basomedial keel on the distiphallus, shares the similarly-shaped hypandrium, with the broad-based, wide and angulate dorsobasal lobe and broad hypandrial arms, and this species is here tentatively ascribed to the same complex, pending a detailed phylogenetic analysis. Redescription: Male (primarily based on ex-alcohol N-T).
Legs. Fore coxa with 15 brown setulae on anterior surface; fore tibia with 4 strong setae on lateral margin, the second basal seta of similar length to other three, with ctenidium of 13 short, sharp black spinules.
Differential diagnosis: Although similar in external characters to other species of the genus occurring in Madagascar (inasmuch as the poor condition of the unique holotype allows comparison), the bizarre structure of the basiphallus and the presence of what is here interpreted as a sclerotised sperm pump, may preclude any direct association. This is the only know species worldwide to possess such a structure and this may be an ancient species, that has been retained as a relict on Madagascar. Associations with other species (if they exist), must await a detailed phylogenetic analysis.

Description: Male
As redescribed for C. balachowskyi, differing in the following respects: Measurements: Overall length unknown; length of head and thorax combined 2.7 mm; length of thorax and scutellum combined 2.6 mm; wing length 4.1 mm.
Legs. Fore coxa with 8 diminutive brown setulae on anterior surface; mid coxa with 2 very strong, lateral, ventrally-directed black setae, 1 very strong medial seta and 5 brown setulae; fore tibia with 4 strong setae on lateral margin, the second basal seta of similar length to other three, with ctenidium of 9 or 10 short, sharp, black spinules, separated from each other by one or more basal spinule widths.
Wing (as in Fig. 35). Relatively short and very broad, tip slightly angularly rounded; veins chestnut-brown, membrane very faintly infuscate brown throughout, very slightly darker in medial region of r 1 and in region of dm-cu crossvein; dm-cu crossvein subvertical, with indentation in basal half; haltere pale yellow.

Curtonotum sakalava
Differential diagnosis: This is the smallest described species of the genus worldwide. It is probably not closely related to other species occurring on Madagascar, but shares some genitalic features in common with C. cuthbertsoni and to a complex of seven as yet undescribed species occurring in the continental Afrotropical Region. The degree of development of the maculae on the abdominal tergites and the strong basomedial keel of the distiphallus, however, may preclude its direct association with this group.

Redescription:
Male (primarily based on ex-alcohol N-T).
Wing (as in Fig. 39). Short, broad basally, tip evenly-rounded, veins chestnut-brown, membrane very faintly infuscate brown throughout, marginally darker in r 1 and anterior half of r 2+3 and in region of dm-cu crossvein; dm-cu crossvein obliquely angled posteriorly, with slight curvature at midlength; haltere dirty yellow.
Differential diagnosis: Not closely related to any other species occurring on Madagascar. It exhibits a number of distinctive features, including the presence of three, rather than two, strong humeral setae, and is the only Afrotropical species described to date with conspicuous brown rings around the sockets of the thoracic setae. The abdorelationship to other species on the continental Afrotropical Region must await the outcome of a detailed phylogenetic analysis. Redescription:

Male
As redescribed for C. balachowskyi, differing in the following respects: Measurements: Overall length 5.6 mm; length of head and thorax combined 3.8 mm; length of thorax and scutellum combined 3.1 mm; wing length 4.6 mm.
Legs. Fore coxa with 21 brown setulae; femora, tibia and tarsi slightly reddish yellow; tibia darker reddish apically; fore tibia with 4 strong setae on lateral margin, black spinules, separated from each other by two or more basal spinule widths.
Wing (as in Fig. 29). Long and narrow, especially cua 1 and m cells, tip evenly-rounded, veins chestnut-brown, membrane deep infuscate brown throughout, darker in r 1 and anterior half of r 2+3 and in region of dm-cu crossvein; dm-cu crossvein subvertical, with slight curvature posteriorly; haltere dirty yellow. Abdomen. Ground colour of tergites 1-5 reddish yellow to grey pruinose, silver pruinose laterally and at apical margins of tergites; tergite 1 with small, oblique blackbrown macula laterally and concolourous medial fascia, these merging slightly at apical margin; tergites 2-5 with extremely broad V-shaped, black median fascia and extensive, concolourous, T-shaped dorsolateral macula, all extensively merging with medial fascia; lateral margin of tergites 2-5 with large, subrectangular, concolourous apically and laterally, with comb of 16 long, thick, black-brown spinules on apical short regular spines arranged in an arc, each side with comb of eight long, thick, blackbrown, apically-directed spines, spinose region with faint brown macula, surface with 437 short setae arranged in irregular rows; sternite 6 ( Fig. 86) narrow at base, laterally expanded (may appear narrower than Fig. 86 in undissected specimens), with deep and broad, V-shaped excision apically, with faint brown maculae medially and fascia laterally, merging apically, clothed in very short, irregular black-brown setulae for most of length, those at apical margin slightly longer and more prominent.
Differential diagnosis: This species is closely related to C. keiseri, differing in the colour of the frons (yellow with indistinct vittae in C. stuckenbergi and brown with distinct vittae in C. keiseri terminalia. Both share the deep brown, infuscate wing membrane, the dove-tailed sternite 6, and straight, ventrally-directed lateral spine and two smaller spines on the distiphallus. Curtonotum stuckenbergi differs from C. keiseri, however, in the angle and degree of curvature of the dm-cu crossvein of the wing, in having the lateral margins of the phallus heavily-sclerotised and the smaller spines of the distiphallus positioned in the left and right lateral regions, rather than basolaterally. The ranges of the two species do not overlap, and they occur allopatrically. Redescription:
Wing (as in Fig. 28). Long, broad, tip evenly rounded, veins chestnut-brown, membrane deep brown infuscate throughout, darker in r 1 and anterior half of r 2+3 and in region of dm-cu crossvein; dm-cu crossvein obliquely angled and moderately straight; haltere dirty yellow.
The Schizophora in general were absent from the Cretaceous, those that were present being ancient taxa (Platypezoidea, Phoridae sensu lato and stem groups) (e.g., Grimaldi & Engel 2005;Wiegmann et al. 2011). The presence of ancient and stemgroup members of the families Camillidae, Drosophilidae and Diastatidae sensu lato (incl. Campichoetidae) in Baltic amber (e.g., Hennig 1965;Tschirnhaus & Hoffeins 2009), indicate that the divergence of ephydroid families probably occurred during the early Paleogene. The vast radiation of acalyprates in general probably took place in the Eocene (e.g., Hennig 1965) and modern genera evolved by the Early Miocene (Arillo Miocene amber from the Dominican Republic (Grimaldi & Kirk-Spriggs, in prep.), formed in a single sedimentary basin, during the early Miocene through early Middle Miocene (Iturralde-Vincent & McPhee 1996), now provides a minimum age for the Curtonotidae in the fossil record. The Curtonotidae are, therefore, far too recent in geological terms to be considered as Gondwanan relicts and only the second of the above-mentioned hypotheses need be considered here.
Cenozoic "sweepstake" dispersal represents transoceanic distribution of African founder individuals from 65.5 Mya to the present (Yoder & Nowak 2006;Vences et al. In a recent study using palaeogeographic reconstructions and palaeo-oceanographic north-east Mozambique and Tanzania eastwards towards Madagascar during the Palaeogene, and concord perfectly with conditions favourable for "sweepstake" dispersal of founder individuals from continental Africa. They conclude, therefore, that rafting (at least in the case of small mammals), may have been the dominant means of transoceanic dispersal during the Cenozoic era, but that this was not apparent after the early In the case of the Insecta and some other invertebrate groups, it has been suggested that aerial dispersal (termed "Anemochore dispersal" in some of the literature), may be as plausible an explanation for founder individual dispersal, and there is much a; Kirk-Spriggs & McGregor 2009, for review). Kirk-Spriggs (2010a) further suggested that the occurrence of the curtonotid Axinota kyphosis on Madagascar (a species of presumed Oriental origin), may have resulted from founder individual transoceanic dispersal via the circulation system of the Indian monsoon.
occurring on Madagascar (i.e., plants, invertebrates, vertebrates and birds), Yoder and Nowak (2006) concluded that there are numerous endemic clades of Malagasy taxa whose closest sister group relationships are to African taxa, and that there appears to be an overwhelming indication of Cenozoic dispersal. They found that nearly half the plants, invertebrates and vertebrates included in these studies exhibit sister group gasy endemics had their relatives or ancestors in Africa. Although this study has been superseded by other studies on similar themes, the general conclusions stated here remain apparent.
In a review of the Diptera on Madagascar, Irwin et al. (2003) noted, that endemism among the Diptera is extremely high on Madagascar, with 80 % of species being endemic to the island. In the case of the genus Curtonotum, partly revised here, 25 species (of which 13 are undescribed) occur in the continental Afrotropical Region, representing 65 % of the regional fauna, while 13 species (of those 6 newly-described) occur on Madagascar, representing 35 % of the Afrotropical fauna as a whole (Kirk-Spriggs in prep.). Only one species, C. pauliani, known from unpublished records from Namibia and South Africa, occurs both on Madagascar and the mainland Afrotropical Region (Kirk-Spriggs in prep.). It should be borne in mind, however, that the continental Afrotropical fauna of the genus is far better sampled and represented in collections than it is for Madagascar, and additional dedicated sampling on the island is sure to reveal further undescribed species. Even prior to his 1977 study of the continental Afrotropical species of the genus, Tsacas (1974), suggested that the seven described Malagasy species of Curtonotum C. pauliani (Ma- dagascar) to C. cuthbertsoni Duda, 1935 andC. quinquevittatum Curran, 1933 (both continental Afrotropical species), these three species being so similar externally that Spriggs (2010a) intimated that the Malagasy Curtonotum faunal lineage may be derived from more than one dispersal event.
Evergreen Rainforest. Humidity transported by the eastern trade winds precipitates on the eastern slopes of the eastern mountain chains, which creates a marked rainfall gradient from the tropical humid north-east and east to the subarid south-west of the island (Vences et al. 2009). Evergreen lowland rainforest cloaks the east coast of the island, extending ca 100 km inland up the eastern mountains (Yoder & Nowak 2006). 445 season at lower elevations and a shorter one at higher elevations. Hence these slopes support broadleaf Evergreen Rainforest (Wells 2003). Central Highlands. At elevations of 800 m and extending well into the interior of the island, the rainforest gives way to the Central Highlands, dominated by moist montane forest (Yoder & Nowak 2006).
Montane Ericoid Thicket. At higher elevations, above 2000 m, the moist montane forests of the Central Highlands are replaced by high elevation thickets, dominated by north, central and south, that reach elevations of up to 2900 m (Vences et al 1; Wilmé et al. 2006). Dry Deciduous Forest (or Central Grasslands). In the western half of Madagascar, below elevations of 800 m, montane forest shifts to Dry Deciduous Forest, dominated by sclerophyllous trees and shrubs, as this area falls within the rain shadow created by the eastern mountains. Deforestation and heavy grazing have impacted heavily on the Central Highlands and Dry Deciduous Forest biomes and today the central parts of the island consists largely of degraded and depauperate grasslands, although some forest remnants (Yoder & Nowak 2006;Wells 2003). Minute Humid Forest relicts are also harboured on isolated massifs within the drier regions of the island (Vences et al. 2009).
Arid Spiny Bush (or Southern Spiny Bush). The arid south-west extension of the deciarid belt become apparent (Yoder & Nowak 2006). This part of Madagascar receives less than 300 mm of rain per year in its driest parts and the streams are ephemeral. It is covered with highly xerophytic "spiny bush" that includes the endemic botanical family Didiereaceae and many other endemic succulents, baobabs and other plants and Sambirano Rainforest and the Sambirano River valley, a region of deciduous forest receives heavy seasonal cipitation produced a rainforest distinct biome known as Sambirano, which is geographically and biologically distinct from the eastern rainforest (Yoder & Nowak 2006).

Distribution and biome associations of the Malagasy Curtonotum fauna
The distributions of the Malagasy species of Curtonotum are tabulated according to the three interpretations of biome-related subunits noted above (Figs 105-107) (Tables  1-3). Table 1 interprets the biome concept of Yoder and Nowak (2006) (Fig. 105). If these data are examined, it can be seen that the Dry Deciduous Forest biome has the most (one of which occurs in the isolated forest remnant to the far north of the island), and the Arid Spiny Bush has four species. Only one species is recorded from the Sambirano Rainforest and none from the Montane Ericoid Thicket. Seven of the 13 species occur in a single biome, one in two, four in three and one in four. Table 2 interprets biogeographic zonation, following Boumans et al. (2007) and partly Wilmé et al. (2006), after Glaw and Vences (2007: 13) (Fig. 106). According to this concept seven species occur in the South (two of which occur at the borderline North East and South East. The North, Sambirano and South Central East have one species each. One species occurs in eight zones, one in four, two in three, four in two Table 3 interprets bioclimatic zonation, following Cornet (1974) and Schatz (2000), after Glaw and Vences (2007: 13) (Fig. 107). From these data it is apparent that the remnant fragments of the zone), followed by the Dry (eight), the Humid (six; one fragthe 13 recorded species occur in more than one zone.
Collectively, these interpretations indicate that biome exclusiveness is largely inconclusive for many Curtonotum spp. and that the biome-restricted patterns that are for species of the genus.
The distribution of the 13 species occurring on Madagascar (illustrated in Figs 92-C. sternithrix and C. keiseri are restricted to the Evergreen Rainforest biome; C. sternithrix to the main eastern rainforest and C. keiseri exclusively to Parc National de la Montagne d'Ambre, a volcanic massif (maximum elevation 1475 m), covered in montane forest that rises from the surrounding dry areas. The sister species of C. keiseri, namely C. stuckenbergi, is restricted to the Central Highlands biome, in Ambohitantely Forest Reserve, which lies at elevations between 1300 and 1650 m. Two species, C. coronaeformis sp. n.  and C. gladiiformis sp. n., are apparently restricted to the Central Highlands biome fragment in the south-central region of Madagascar, both being only recorded from Fianarantsoa, near Parc National de la Isalo. Curtonotum coronaeformis sp. n., and its sister species C. parkeri sp. n., occur sympatrically, with C. parkeri sp. n. restricted to the south of the island. Curtonotum rinhatinana sp. n. is restricted to the Dry Deciduous Forests at Ankarafantsika National Park in the north-west of Madagascar, which forms a mosaic of dense, Dry Deciduous Forest. Two species, C. sakalava and C. irwini sp. n., although occurring in more than one biome type, are predominantly associated with the Arid Spiny Bush and the Dry and Subarid bioclimatic zones. Curtonotum boeny is restricted to the Dry Deciduous Forest biome, recorded from two localities: Ambato-Boeni and Parc National Tsingy de Memaraha. Its sister species, C. griveaudi sp. n., is much more widely distributed, occurring in the north-east, west and south-west of the island. Curtonotum pauliani occurs mainly in the north-east of Madagascar and is the only species of the genus recorded as occurring in the Sambirano Rainforest biome. Lastly, C. balachowskyi is widely distributed in Madagascar and occurs in four of Madagascar's biome types. Vences et al. (2009) noted that radiations of Malagasy lineages resulted in a wealth of microendemics restricted to small ranges within the landmass of Madagascar and arid west and humid east (see also Dewer & Richard 2007). Populations of widespread species adapted to humid conditions remain isolated in Humid Forest relicts in predominantly dry areas during periods of cool and dry climate and, over time, diverge to become separate species without adapting to different climatic conditions. This may explain the microendemic species of Curtonotum (noted above) that are apparently dryer western and northern regions of Madagascar (Vences et al. 2009). The previous assumption that deforestation of the Central Highlands and Dry Deciduous Forest biomes and subsequent forest fragmentation is wholly anthropogenic is a myth. This is evidenced by pre-anthropogenic charcoal and fossil data that demonstrate Pleistocene oscillation in the extent of these biomes and their associated vegetation cover (Bond et al. 2008;Burney et al. 2003;Vences et al. 2009). Lineages of the Malagasy Curtonotum fauna will become more apparent once the combined morphological and molecular phylogeny of the Curtonotidae as a whole is published in Part IV of this revision, and Bayesian divergence dates are established for some of the African and Madagascan clades.
APPENDIX II Geographical co-ordinates used to map distributions plotted on Figs 92-104, based on material examined in this study and listed in the material examined sections. Vegetation types listed follow Moat and Smith (2007). Latitude