Review of the Afrotropical subgenus Disneyempis ( Diptera : Empididae )

The Afrotropical subgenus Disneyempis Smith of the genus Empis L. is redescribed and redefined on the basis of three synapomorphies, namely labrum lengthened, male eyes more or less broadly separated on frons with all ommatidia of equal size, fe­ male abdomen with bluish to purplish metallic reflections on terga 2-5. At present, the subgenus comprises six species: E. (D.) hirsutipennis Smith as type species, E. (D.) jacksoni Smith, E. (D.) argentea sp. n., E. (D.) spinifemorata sp. n., E. (D.) proboprocera sp. n. and one unnamed species E. (D.) sp. 1. All species are described [except E. (D.) sp. 1] and keyed. The subgenus has a tropical African geographical range including Cameroon, Democratic Republic of Congo (formerly Zaire), Republic of Congo and Gabon.


INTRODUCTION
Dance flies of the tribe Empidini (Empididae; Etnpidinae) form a large worldwide group of about 1,200 de scribed species.Two very large genera, Rhamphomyia Meigen, 1822 and Empis L., 1758, contain some 90% of described species.A subgeneric classification based on the Palaearctic fauna has been established for these two genera (Bezzi, 1909).However, as Chvála (1994) pointed out, this subgeneric classification is hardly applicable to other geographical regions and several subgenera appear unnatural.Nevertheless, the subgeneric classification has been partly followed for the Afrotropical fauna by Smith (1967aSmith ( , b, 1969Smith ( , 1971Smith ( , 1976Smith ( , 1980)), who published the only significant work on the regional Empidinae.Species in which wing vein Ml or veins Ml and M2 are abbrevi ated were placed in the subgenus Coptophlebia Bezzi, 1909 (Empis) and species with all median veins complete in Empis s. str.Four species were placed in the genus Rhamphomyia without subgeneric placement.For a unique species, Empis hirsutipennis Smith, represented by a single female from Cameroon, Smith (1976) estab lished a new subgenus Disneyempis of the genus Empis on account of the presence of three unique characters: A bluish metallic abdomen, a radial fork (vein R4+5) lengthened with an acute angle, and densely microtrichiate wings.
As Chvála (1994) already noted, redefinition of the subgenera Empis s. str.and Coptophlebia is needed, for at least two reasons: First, the abbreviation of vein Ml is present also in species belonging to other groups, e.g.E. (Kritempis) lívida L.; second, the complete/abbreviated vein Ml is a polymorphic character, since some speci mens of Empis s. str.show an abbreviated Ml and con versely some specimens of Coptophlebia a complete M1.Consequently, the subgenera are not well defined even for the Palaearctic region.To clarify these taxonomic problems, Palaearctic Empis s. str.and Coptophlebia have been divided already into several inferred monophyletic groups (Syrovátka, 1991;Chvála, 1994).Amongst these changes, the name of Coptophlebia becomes reserved for a small Palaearctic group of six species (Chvála, 1994;Daugeron, 1997b,c).
With the aim of proposing a future phylogenetic analy sis of the tribe Empidini, a comparable study has been performed for the Afrotropical Empidini for which six groups were tentatively identified, of which one is repre sented also in the Oriental and Australasian regions (Daugeron, 1997c(Daugeron, , 1999;;Appendix).This paper presents a revision of one of this group, the subgenus Disney empis, comprising six closely related species: E. hirsuti pennis Smith, the type-species of the subgenus Disney empis, E. jacksoni Smith (described in the subgenus Coptophlebia: Smith, 1971) the female of which is newly described here, as well as four new species.To attest its monophyly, this group was compared with all groups considered previously by any author as potential relatives.

Assessment of the monophyly of Disneyempis
According to previous phylogenetic and taxonomic studies (Syrovátka, 1991;Chvála, 1994;Daugeron, 1997c and in prep.) and cladistic analysis of important material from Palaearctic and Afrotropical regions (Daugeron, 1997c and in prep.), several species-groups, including Disneyempis, seem to form a mono phyletic lineage within the tribe Empidini on the basis of a slen der, strongly sclerotized proboscis, especially the labium, and other characters in the venation.Consequently, the monophyly of Disneyempis was preferably assessed by comparison with members of this group as follows: First, a list of 13 species-groups was compiled.This list com prises 12 species-groups belonging either to Empis s. str.or Coptophlebia, as well as the subgenus Aclonempis Collin, 1926 of the genus Rhamphomyia since this subgenus is considered to be more related to Empis s. str.and Coptophlebia than to other members of Rhamphomyia (see for example Chvála, 1994).Second, morphological comparison was made between species of Disneyempis and remaining groups.Considering the current ideas of the phylogeny of the entire tribe Empidini, the charac ters found only in Disneyempis appear to be synapomorphic and support monophyly of that taxon.

Material and morphological terms
This study is mainly based on pinned adult specimens belong ing to collections of Diptera of the Muséum national d'Histoire naturelle, Paris (MNHN), the Natural History Museum, London (BMNH), the Natal Museum, Pietermaritzburg and the Royal Belgian Institute ofNatural Sciences, Brussels.
The morphological terms follow McAlpine (1981), except for the male genital sclerites, the interpretation of which follows Sinclair et al. (1994) and Cumming et al. (1995).Consequently the traditional male genital terms of dorsal, lateral and ventral lamellae are replaced by cerci, epandrium and hypandrium re spectively.However, as already explained (Daugeron, 1997a), the term epandrial lamella is used for the lateral sclerites form ing the epandrium.In all descriptions, the length of labrum is given relative to head height.
The male genitalia and female postabdomen were dissected and macerated in hot 10% KOH; specimens were drawn in gly cerine using a camera lucida.

MONOPHYLY OF DISNEYEMPIS
Three synapomorphies were found to attest the monophyly of the subgenus Disneyempis: The length of the labrum, the arrangement of eyes and size of ommatidia in male, and the coloration of the female abdomen.Of the characters originally given by Smith (1976) to define the subgenus Disneyempis, only the coloration of the female abdomen is thus retained.The other two characters (radial fork lengthened and microtrichiate wings) therefore are without subgeneric significance.
First, the labrum is always very long, between 3.5 and 5 times the head height (= 5 to 7 times the head width).In all other groups examined (Appendix), the labrum often is longer than the head but rarely more than twice; in a few species like Empis pennipes L. the labrum is about three times the head height.
Second, eyes of known males are either distinctly sepa rated on the frons, although less than in females, or only separated by a narrow space, thus almost holoptic; the up per ommatidia are never enlarged, and all ommatidia are of equal size or lower ommatidia a little enlarged.
Holoptic eyes with upper ommatidia enlarged, which is hypothesized to represent the ground plan condition in the Empidoidea (Wiegmann et al. 1993), are present in males of other groups examined (Appendix).Nevertheless, as the arrangement of eyes is homoplastic within the Empi doidea (Sinclair, 1995;Daugeron, 1999), the dichoptic eyes with all ommatidia of equal size or lower ommatidia a little enlarged is only tentatively considered synapomorphic for species of Disneyempis.
Third, the female abdomen exhibits bluish to purplish metallic reflections on terga 2-5.This character is pro posed only as a possible additional synapomorphy for Disneyempis, as the females of two species are yet un known.Also it is tentatively hypothesized that the colour or tint of Disneyempis species changes during life.I found three females of E. (C.) jacksoni in the MNHN col lections.The first one was collected with a male at Dimonika (Congo) on 12 April 1975.Its abdomen is only shining brown and both specimens are brown in general colour but not very dark.Two days later (on 14 April), at the same place, four specimens, two males and two fe males, were collected.These specimens are also brown in general colour, but distinctly darker and the females ex hibit a metallic abdomen.Although I cannot rule out fe male polymorphism, the hypothesis of colour change during the life of the fly seems more likely.
A few other Empidini exhibit metallic reflections, namely species of two Neotropical genera, Lamprempis Wheeler & Melander, 1901and Porphyrochroa Melander, 1927(Rafael & Cumming, 1998), and one Neotropical species of the genus Empis, E. fulvicollis Collin, 1933.These taxa are not closely related to Dis neyempis on account of several morphological differences especially in the structure of the proboscis.In addition, metallic reflections are present in both sexes in these spe cies contrary to species of Disneyempis in which only fe males are metallic.I consider therefore metallic reflec tions present in species of Disneyempis on the one hand and some Neotropical species on the other hand as homo plastic.
Thus the subgenus Disneyempis seems to represent a monophyletic group of six species within the tribe Em pidini.Nevertheless the confirmation of this hypothesis requires collecting of additional specimens and the dis covery of missing sex in some species.Diagnosis.Species of medium to large size, brown in general colour, abdominal terga of females partly metallic with bluish to purplish reflections, only shining in juve nile specimens, with strong, long black bristles (except for the yellow-brown pennate bristles of fore male tarsi present in two specimens of E. spinifemorata).Male eyes broadly separated on frons or only separated by a narrow space, ommatidia of equal size or lower ommatidia some what enlarged.Labrum very long, slender, strongly sclerotised, labium with characteristic annulations.Pilosity very developed, especially in males: strong, often very long black bristles on scutum and legs.Laterotergite with fan of long bristles.Costa ending at R5, R4+5 forked, discal cell strongly truncate.Male cercus bifid at tip or lengthened posteriorly, hypandrium almost paired, con sisting of two lamellae only connected in subapical point.
Male.Head with lower margin of face sometimes lengthened.Flagellum with three fiagellomeres, second and third more or less long.Labrum always very long, prementum and label la with characteristic annulations on the anterolateral and outer margins respectively, labella slender, strongly sclerotised, bare.Eyes distinctly sepa rated on frons (E.jacksoni, E. spinifemorata) or only separated by narrow space {E.argentea, E. probo-procera), all ommatidia of equal size or lower ommatidia enlarged.
Legs with femora with more or less fine bristles, espe cially on mid femur in ventral position.Tibiae and tarsi with distinct bristles, often strong, long on first tarsomere, more or less spine-like on second.
Length.Body 4.5-10.5 mm, wing 5.6-8.5 mm.Remarks.Disneyempis can be distinguished from the E. (Coptophlebia) chrysoceraand E. (C.) namwamba-groups by its three synapomorphies as well as the absence of pennate bristles on legs of females.Disneyempis also differs from the remaining studied Empidini especially by the presence of distinct annulations on the labium and the membranous spermatheca.

Male
Head.Occiput dark brown with row of rather fine pos tocular bristles.Ocellar triangle with distinct pair of bris tles.Frons dark brown, rather shining, reduced, somewhat enlarged above antennae.Face brown, shining.Scape and pedicel brown, first flagellomere brown, lighter at base, long (five times length of pedicel), second and third flagellomeres brown, almost as long as scape.Labrum long (almost four times the head height), brown, labium with characteristic annulations, labella brown-yellow, slender, palpus not visible.Eyes only separated on frons by nar row space, lower ommatidia slightly enlarged.Thorax.Antepronotum brown with 1 row of about 12 distinct bristles.Postpronotal lobes brown with 1 strong, long basal bristle and a few finer and shorter.Proepisternum bare, prostemum with 4 distinct bristles.Scutum with minute silvery pubescence.Acrostichals absent ex cept for 1 short bristle at middle.Dorsocentrals uniserial, absent anteriorly, strong, very long except for the first finer, shorter pair.Intraalar absent.One row of 4 strong, very long supraalars.One notopleural less strong and long than supraalars.Postalar calli with 1 strong, very long bristle, and in front of this, a second one, shorter and finer.Scutellum brown, with 2 strong, very long apical bristles and 2 shorter, finer subapicals.Mediotergite brown.Laterotergite brown, with fan of about 5 strong, very long bristles as well as a few finer.Anterior and pos terior spiracles black-brown.
Legs.Fore coxa yellow-brown with silvery minute pu bescence anteriorly.Fore femur extensively yellow be coming brown at apex.Fore tibia brown-yellow, fore tarsi black-brown.Mid coxa and femur brown, mid tibia brown with minute anterolateral silvery pubescence in apex.Mid tarsi black-brown.Hind femur extensively yel low becoming brown dorsally and at apex.Hind tibia and tarsi dark brown.All tibiae more or less dilated at apex.All femora with short dorsal bristles, almost bare ventrally with only 6 to 7 fine bristles at basal half.Fore tibia with strong, long dorsal bristles except at base and 2 very long bristles at apex.Mid tibia with 4 strong, long ventral bristles, 3 strong, very long anterodorsals at apical 2/3 and 1 row of numerous rather short posterodorsals.Hind tibia with numerous strong, long dorsal and ventral bris tles.Fore and hind first tarsomere long, the former almost as long as the next 4 together and the latter 1.5 times the length of the next 4 together; both with numerous strong, long bristles, hind first tarsomere in particular with ven tral spine-like bristles.First tarsomere of mid tarsi with fine, not very long posteroventral bristles in basal half and several very strong, spine-like, longer ventrals.Other tarsomeres with a few strong bristles especially at apical tip.
Wing (Fig. 5) brown.Sc abbreviated.Ml and M2 com plete, distinctly less sclerotised at tip, A1 evanescent to wards the margin of wing.Anal lobe not very developed, consequently anal angle obtuse.Haltere yellow.
Abdomen.First segment and anterior half of second brown-yellow, otherwise subshining dark brown.Mar ginal bristles rather numerous, strong, especially at mar gin of terga.Some silvery reflections occur particularly at base.

Female
Unknown.
Etymology.From the Latin word "argentabas" meaning "sil very", in reference to the presence of silvery reflections on di verse body areas. Distribution.Gabon.

Differential diagnosis.
By its remarkable silvery pu bescence, especially on the scutum, E. argéntea cannot be mistaken with another species of the subgenus, although it resembles E. proboprocera by the posterior lengthening of the cerci, the weak development of the anal lobe of the wing and the absence of acrostichals.
Thorax. Brown to dark-brown.Antepronotum with distinct lateral bristles.Postpronotal lobes with 1 distinct basal bristle.Scutum dark brown with brown minute pu bescence especially laterally and posteriorly in the prescutellar depression.Acrostichals distinct, uniserial to irregularly biserial, dorsocentrals uniserial, rather strong, long.Two strong, long supraalars, respectively pre-and postsutural.Three strong, long notopleurals.One strong, long postalar.Scutellum brown, with 1 pair of strong, long apical bristles, 1 pair of fine, rather short subapicals.Wing.Dark brown, densely microtrichiate especially in anal cell.Sc, Ml distinctly abbreviated, M2 evanescent at tip, other veins, including Al, complete.R4+5 of unusual shape: R4 very long, forming with R5 an acute angle.Anal lobe distinct but anal angle not very acute.Halteres with yellow base, dark-brown knob.
Legs.Fore coxa and femur yellow-brown, mid and hind femora yellow-brown, all tibiae and tarsi dark brown.Fore femur with few fine ventral bristles.Fore tibia with 1 row of short, rather strong dorsal bristles, numerous fine, short ventrals.First tarsomere of fore tarsi with rather long, strong ventral and dorsal bristles, other tarsomeres with distinct bristles at apex.Mid femur with short, rather fine ventral and dorsal bristles.Mid tibia with rather short dorsal bristles, fine ventrals, stronger and rather long at apical %, anterior face densely covered with numerous short bristles.First tarsomere of mid tarsi with 2 rows of strong dorsal bristles, other tarsomeres with dis tinct bristles at apex.Hind femur with numerous short an terolateral bristles especially in apical half.Hind tibia with 1 row of anterodorsal spine-like bristles, longer at apical 'A, 1 row of spine-like posterodorsals only in basal half; anterior face of tibia densely covered with short spine-like bristles at basal half.First tarsomere of hind tarsi with 1 row of antero-and posteroventral bristles, longer posteriorly.Other tarsomeres with distinct bristles at apex.
Abdomen.Marginal bristles distinct.First tergum, ba sal part of second and last three terga brown, not shining.Other terga and posterior part of second shining, dark brown to metallic bluish to purplish.Postabdomen modi fied (Fig. 6): Tergum 8 with distinct desclerotised medioantcrior part, enlarged; sternum 8 produced laterally beneath tergum; pleural membrane between tergum and sternum 8 entirely absent; cercus small, shorter and dis tinctly less sclerotised than usual, almost bare with few minute bristly setae at apex.

Male
Unknown.
Differential diagnosis.E. hirsutipennis is characterised by the shape of the radial fork and the presence of densely microtrichiate wings.By its modified postabdo men (Fig. 6) and the peculiar pilosity of hind tibiae, it re sembles an unamed species E. (D.) sp. 1 (Fig. 7).

Male
Head.Occiput black with fine, distinct postocular bris tles.Ocellar triangle black, prominent, with 1 pair of dis tinct bristles.Frons black, never as wide as one ocellus at middle.Face dark brown, more than twice as wide as frons.Antenna black-brown, first flagellomere long, sec ond and third flagellomeres as long as scape and pedicel together.Labrum very long (5 times the head height), labrum yellow-brown, labium with characteristic annulations, labella slender, bare, strongly sclerotised, palpus black, rather reduced, with 1 fine, long apical bristle.Eyes dichoptic, lower ommatidia enlarged.
Thorax.Antepronotum brown with rather strong bris tles on each side.Proepistemum bare, prostemum with fan of distinct bristles.Postpronotal lobes brown with 1 strong, long basal bristle, several shorter anteriors.Scu tum brown to dark brown.Acrostichals biserial, dorsocentrals biserial anteriorly, uniserial posteriorly, with 2 strong, very long prescutellar bristles.Two strong, long supraalars, respectively pre-and postsutural.Three strong notopleurals, 2 of which very long.One strong, long postalar.Scutellum brown with 2 strong, very long apical bristles.Laterotergite with fan of numerous bristles.Ante rior and posterior spiracles dark brown to black-brown.
Legs.Coxae and femora yellow to yellow-brown, tibiae and tarsi black-brown.Fore femur without distinct bris tles except for some dorsals.Mid and hind femora with antero-and posteroventral rows of fine, rather long bris tles.All tibiae with 1-2 dorsal rows of strong, long bris tles especially distinct apically.Fore and hind tibiae with only fine, short ventral bristles, mid tibia with 1 row of strong, long ventrals.Fore and hind first tarsomere, at least as long as four next tarsomeres together; former with strong, long dorsal and ventral bristles, latter with strong, short bristles except for a few dorsals which are slightly longer.First tarsomere of mid tarsi with 3 strong, long dorsal bristles.All other tarsal bristles short, sometimes very strong, spine-like.
Hypopygium (Figs 9,10).Cercus bifid apically, with numerous rather fine basoventral bristles as in E. spinifemorata.Epandrial lamella rounded at tip with strong, rather long dorsal and ventral bristles only in api cal half.Hypandrium as in E. spinifemorata in shape and structure.Phallus rather thin, of usual shape for Dis neyempis.

Female
Similar to male except for the following characters: Eyes broadly separated on frons, lower ommatidia en larged.Frons almost as broad as face.Pilosity reduced es pecially on legs and abdomen.Abdomen with the first tergum brown, terga 2-5 shining dark brown to metallic bluish to purplish reflections, terga 6-8 and 10 brown to yellow-brown, neither metallic nor shining.Cercus longer than broad, dark brown, uniformly covered with fine, very short bristly hairs.
Variation.One of the three studied females, probably newly emerged, lacks the metallic bluish to purplish ab dominal reflections, with terga 2-5 only shining brown.Differential diagnosis.E. jacksoni differs from all species of Disneyempis by its very large size.It resem bles E. spinifemorata from which it differs in the form of the apically bifid male cercus and the absence of femoral spine-like projections in the male.

Male
Head.Occiput and ocellar triangle almost invisible.Occiput dark brown with 1 row of postocular bristles.Frons very reduced, somewhat enlarged in triangle above antennae, black.Face dark brown, somewhat shining.Scape brown (twice length of pedicel), pedicel paler brown, first flagellomere dark brown, long (four times as long as pedicel), second and third flagellomeres black, as long as scape.Labrum very long (5 times the head height), yellow-brown, labium with characteristic annulations, labella slender, bare, strongly sclerotised, palpus re duced, dark brown, with distinct rather short apical bristle.Eyes only separated by narrow space, all ommatidia of equal size.
Wing (Fig. 14) dark brown.Sc distinctly abbreviated.Discal cell strongly truncate.Ml distinctly abbreviated, M2 abbreviated just before the margin of wing.A 1 com plete but weakly sclerotised towards wing margin.Anal lobe weakly developed, consequently anal angle obtuse.Haltere entirely yellow.
Abdomen.First segment and anterior half of second yellow, otherwise terga dark brown, sterna brown.Strong, long marginal bristles on first 6 segments.Ster num 8 well developed posteriorly with numerous strong bristles at margin.
Hypopygium .Cercus of structure and shape close to E. argéntea.Epandrial lamellae connected ventrally by unusual anteroventral expansion; dorsoapical tip of each lamella rounded, bearing numerous bristles.Hypandrium divided in two lamellae as in other Dis neyempis.

Female
Unknown.
Differential diagnosis.E. proboprocera presents an exceptional character in the male genitalia: the ventral connection of epandrial lamellae, under the phallus.This character combined with the shape of male cercus, the en tirely yellow halteres and the non-silvery scutum allow to distinguish this species from all other species of Disneyempis.

Empis (Disneyempis) spinifemorata sp. n.
Species of medium size, characterised by the presence of 2 strongly sclerotised spine-like projections at the base of the male hind femora (Figs 17,18).

Male
Head.Occiput black-brown, with 1 row of distinct pos tocular bristles.Ocellar triangle prominent, black, with pair of distinct bristles.Frons black shining, a little wider than one ocellus.Face lighter than frons in lower part, 1.5 times as broad as frons.Antenna black, first flagellomere somewhat lengthened.Labrum very long (more than 4 times the head height), labrum yellow-brown, labium with distinct characteristic annulations, prementum and labella brown, palpus dark brown with rather long, fine apical bristle.Eyes dichoptic, lower ommatidia a little en larged.
Legs (Figs 17,18).Fore coxa yellow, mid and hind coxae brown.Femora yellow, tibiae yellow to brown and tarsi dark brown.Fore femur almost without bristles.Mid femur with distinct fine ventral bristles.Hind femur with some fine ventral bristles and more distinct dorsals apically.Base of hind femur with a strong pointed posterodorsal black spine-like projection (Fig. 17), and with a rather rounded posteroventral spine-like projection bear ing brush of short bristly hairs (Fig. 18).Fore and mid tibiae with only short ventral bristles except for 1-2 strong, long bristles; 1 row of strong, long to very long dorsals.Hind tibia resembles mid tibia, ventral bristles distinctly more numerous.All tarsi with 1 row of about 10 strong, long dorsals as well as numerous ventrals  Abdomen.Brown to black-brown, somewhat shining on first tergum.Marginal bristles distinct especially on sides of terga.

Female
Similar to male except for the following characters: Eyes more separated on frons, lower ommatidia enlarged.General pilosity of body shorter especially on legs and abdomen.Hind femur without basal spine-like projections.Terga 2-5 metallic with bluish to purplish re flections.Cercus longer than broad, uniformly covered with very short, fine bristly setae.
Variation.Two males, the holotype and one paratype, exhibit several very long, rather fine yellow-brown pennate bristles at tip of the first tarsomere and on the second one of the mid tarsi, whereas in the remaining males, three other paratypes, all bristles of the tarsi, although strong and also very long, are simple and black.The hypopygium of these five males appears identical and all males are considered conspecific; this difference is there fore viewed as a polymorphism related to the ornamenta tion of the midlegs.Alternatively, it is possible that the presence of one or the other character state is an anomaly as is often the case with other characters (for example wing venation).

DISCUSSION
Three pairs of species can be distinguished within Dis ney emp is.Firstly, E. argentea and E. proboprocera, two species with male cercus considerably prolonged, the anal lobe weakly developed and without acrostichals.Sec ondly, E. hirsutipennis and E. sp. 1, for which the pres ence of very short spine-like bristles on the anterior face of hind tibiae and the modified postabdomen in the fe male are very characteristic.Thirdly, E. jacksoni and E. spinifemorata, defined by the shape (bifid at tip) and the pilosity (numerous short basoventral bristles) of male cer cus.
At present the lack of one sex in four species of Disneyempis (female unknown for E. argentea and E. probo procera, male unknown for E. hirsutipennis and E. sp. 1 ) do not allow to establish accurately the relationships within the subgenus, especially between the abovementioned three pairs of species.Consequently, in order to analyze cladistically Disneyempis as well as to confirm its monophyly, the collect of additional specimens is needed.
Appendix.Material examined.The region where the group is distributed (AFR -Afrotropical, AUS -Australasia, ORI -Ori ental, PAL -Palaearctic) and the corresponding reference are indicated in parentheses and in square brackets respectively.Al though the phylogenetic and taxonomical treatment of Afro tropical groups will be detailed in several papers to come, their monophyly is tentatively defined following Daugeron (1997c).(*) denotes uncertain monophyly.Genus Empis L. subgenus Disneyempis Smith (AFR) Genus Empis L. subgenus Coptophlebia Bezzi albinervis-group (PAL) (Chvála, 1994) bivittata-group (AFR) (Daugeron, 1997c).A group of nine species only distributed in South Africa, defined on the basis of a massive and apically bifid hypandrium.
chrysocera-group (AFR) (Daugeron, 1997c;in prep.).A group of ten species widely distributed in Africa, defined by the anterior connection of epandrial lamellae and the division of cerci into two lobes.Two complexes of species can be distin guished in the chrysocera-group based on modifications in male pregenital segments.

Distribution.
Central Africa (Fig.19): Cameroon, Demo cratic Republic of Congo (formerly Zaire), Republic of Congo, Gabon.The subgenus seems strictly tropical in its distribution.No specimens of Disneyempis are known from the southern part of Africa.

Fig. 8 .
Fig. 8. E. (D.)jacksoni Smith, female, habitus.Mesepistemum dark brown, mesepimeron brown.Laterotergite with fan of numerous strong, long bristles.Ante rior and posterior spiracles black-brown.Wing.Dark brown, densely microtrichiate especially in anal cell.Sc, Ml distinctly abbreviated, M2 evanescent at tip, other veins, including Al, complete.R4+5 of unusual shape: R4 very long, forming with R5 an acute angle.Anal lobe distinct but anal angle not very acute.Halteres with yellow base, dark-brown knob.Legs.Fore coxa and femur yellow-brown, mid and hind femora yellow-brown, all tibiae and tarsi dark brown.Fore femur with few fine ventral bristles.Fore tibia with 1 row of short, rather strong dorsal bristles, numerous fine, short ventrals.First tarsomere of fore tarsi with rather long, strong ventral and dorsal bristles, other tarsomeres with distinct bristles at apex.Mid femur with short, rather fine ventral and dorsal bristles.Mid tibia with rather short dorsal bristles, fine ventrals, stronger and rather long at apical %, anterior face densely covered with numerous short bristles.First tarsomere of mid tarsi with