Diptera, Diopsidae) with Description of a New Species from Guinea-Bissau Hans R

Tijdschrift voor Entomologie 156 (2013) 161–189 brill.com/tve

A revision of the genus Diopsina Curran (Diptera, Diopsidae) with description of a new species from Guinea-Bissau Hans R. Feijen & Cobi Feijen

An updated diagnosis is given for the genus Diopsina and a key to the seven species presently recognised. From Guinea-Bissau, Diopsina ﬂuegeli sp. n. is described. Based on new material and on earlier described specimens, updated diagnoses are given for all Diopsina species. Additional descriptive information is presented, especially for abdominal structures and on sexual dimorphism in relation to eye span. Photographs illustrate some earlier described species. Biometrical data are presented which support the earlier division of the genus into the Diopsina nitida-group and the Diopsina africana-group. Several morphological characters and the phylogenetic position of Diopsina are discussed. Only limited information on the ecology of Diopsina is available, but for species of the Diopsina africana-group a close relation with clumps of Cyperaceae appears conﬁrmed. Hans R. Feijen*, Naturalis Biodiversity Center, P.O. Box 9517, 2300 RA Leiden, The Netherlands. [email protected] Cobi Feijen, Naturalis Biodiversity Center, P.O. Box 9517, 2300 RA Leiden, The Netherlands

Introduction In the past twelve years, several studies dealt with In a note on the genus Diopsina Curran, 1928, Feijen the phylogenetic relationships within the Diopsi- (1978) sorted out the confusion around this genus, nae, especially at genus level (Meier & Hilger 2000, involving the genera Te le op s is Rondani, 1875, Cyr- Baker et al. 2001, Meier & Baker 2002, Kotrba todiopsis Frey, 1928 and, as junior synonym, Phryx- 2004, Kotrba & Balke 2006, Marshall et al. 2009, odiopsis Séguy, 1955. In later contributions (Feijen Kotrba et al. 2010). These studies were based on 1981, 1984) the genus was reviewed while three morphological and/or molecular analyses. The place new species were described. This paper will deal of Diopsina was until recently not very clear, espe- with additional collections of Diopsina and describes cially due to the absence of molecular data. Kotrba a new species from Guinea-Bissau. For earlier de- et al. (2010) were the first to provide a molecular scribed species, additional morphological and bio- dataset for a species of Diopsina leading to a con- metrical information will be given. Based on mea- firmation of the placement of Diopsina in a mono- surements of new material and of Diopsina spec- phyletic clade with Diopsis Linnaeus, 1775 and Eu- imens earlier reported upon (Feijen 1978, 1981, rydiopsis Frey, 1928 and the proposal of a sistergroup 1984), data will be presented on sexual dimorphism relationship between Diopsina and Diopsis.Thispo- in relation to eye span for the Diopsina species. The sition of Diopsina will briefly be discussed. phylogenetic relevance of these biometrical data will be discussed.

Tijdschrift voor Entomologie 156: 161–189, Tables 1–4. Figs 1–57. [ISSN 0040-7496]. brill.com/tve © Nederlandse Entomologische Vereniging. Published by Koninklijke Brill NV, Leiden. Published 20 December 2013. DOI 10.1163/22119434-00002029

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Materials and methods NMSA Natal Museum, Pietermaritzburg Kwa- Specimen preparation, dissection of abdomens, Zulu Natal, South Africa. imaging and terminology used RMCA Musee Royal de l’Afrique Centrale, For Diopsina ﬂuegeli sp.n.andotherDiopsina species Tervuren, Belgium. pinned specimens were available. For Diopsina ni- RMNH Naturalis Biodiversity Center (for- tida (Adams, 1903) and Diopsina africana (Shillito, merly Rijksmuseum van Natuurlijke 1940), ﬂies preserved in 70% ethanol were used for Historie), Leiden, The Netherlands. DNA analysis. For study of abdominal structures, SMNS Staatliches Museum für Naturkunde, abdomens were removed and macerated in hot 10% Stuttgart, Germany. KOH for several minutes. After dissection of the gen- ZSM Zoologische Staatssammlung, Mün- ital structures, the abdomens were mounted in glyc- chen, Germany. erol for temporary slides and in Hoyer’s medium for The following abbreviations are applied in the text: permanent slides. Material of temporary slides was D = rate of dimorphism; IVS = inner vertical seta; later transferred to genital vials and pinned under the OVS = outer vertical seta; SE = standard error. original specimens. Drawings were made with a Leica Wild M3B dissecting microscope and an Olympus Taxonomy CH compound microscope, using a drawing tube. Photographs were made with an Olympus motorised Family Diopsidae Billberg stereomicroscope SZX12 with AnalySIS Extended Focal Imaging Software. For morphological termi- Diopsidae: Billberg, 1820: 115 (as Natio Diopsides). nology, the system proposed by Cumming & Wood Type-genus Diopsis Linnaeus, 1775: 5. (2009) is broadly followed. Genus Diopsina Curran

Measurements Diopsina Curran, 1928a: 5, type species Diopsina ferruginea Curran, 1928a by orig. des. (junior synonym of Diopsina The following morphometric parameters were mea- nitida (Adams, 1903)). sured using a Leica Wild M3B: eye span, body Phryxodiopsis Séguy, 1955: 1106, type species Phryxodiopsis length, wing length, length and width of front fe- kaeleana Séguy, 1955. mur, length of scutellum, length of scutellar spine, length of apical seta, length of inner and outer Not Diopsina Plötz, 1885: 2 (in Aurivillius 1886: vertical seta (IVS, OVS) and eye-stalk diameter. 522). The ‘subfamily’ name Diopsina (Noctuidae, These measurements were used to calculate ratios Lepidoptera) was an error for the subfamily name like eye span/body length, scutellar spine/scutellum, Dyopsina Plötz, 1885 (now correct as Dyopsinae): length/width in femur 1, IVS or OVS/eye stalk dia- 23, based on the genus Dyops Guenée, 1852. Al- meter and apical seta/scutellar spine. For the length though not strictly speaking an homonym, the error of the front femur the distance between the proximal is now indicated. and distal ends was taken, while the width of this Catalogue of the genus Diopsina femur was measured at the widest section in lateral view. Length of the setae is measured from base to africana Shillito, 1940: 160 (Cyrtodiopsis). holotype, 1 paratype from Uganda, W.P., Nyakasura, Toro. 1 paratype tip. For the procedures for other measurements can (as ‘allotype’) from Uganda, W.P., Mpanga Bridge, nr. Fort be referred to Feijen & Feijen (2011). Portal. Type series in BMNH. draconigena Feijen, 1981: 469. holotype, 5,4 paratypes International codens from South Africa, Natal, Giant’s Castle Reserve, Drakens- berg. 1,1 paratypes from Pietermaritzburg South Africa AMNH American Museum of Natural History, New York, U.S.A. and 1 paratype from Gillits, St. Hellier, South Africa. 1 paratype from Roma, Lesotho. Type series in NMSA, ex- BMNH The Natural History Museum (for- cept for two paratypes in RMNH. merly British Museum (Natural His- intermedia Feijen, 1984: 22. holotype, 1 paratype from tory)), London, U.K. D.R. Congo, Biano, Shaba (Katanga) (BMNH), 1 pa- FBUB Biological Collection, Universität Bie- ratype from D.R. Congo, Parc National de la Garamba lefeld, Bielefeld, Germany. (RMCA). KSBS University of Kansas, State Biological ﬂuegeli sp. n. holotype from Bissorã, Guinea-Bissau Survey of Kansas, Lawrence, Kansas, (RMNH). USA. kwaipai Feijen, 1981: 474. holotype, 18,20 paratypes MNHNP Muséum National d’Histoire Natu- from Malawi, Zomba. Type series in RMNH, except for relle, Paris, France. four paratypes in NMSA. nitida Adams, 1903: 46 (Teleopsis). holotype from Zim- babwe, Salisbury (KSBS).

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ferruginea Curran, 1928a: 5. holotype from D.R. Congo, male tergum 8 consisting of two sclerites . . Faradje (AMNH)...... D. nitida-group 4 kaeleana Séguy, 1955:1106 (Phryxodiopsis). holotype 2. Facial teeth absent, two pollinose spots from Cameroon, Kaélé (MNHNP). on tergum 3, average ratio eye span/body schulteni Feijen, 1978: 20. holotype from Sokodé, Togo length 72%, on the average 7.7 tubercles (SMNS). per femur 1, female tergum 7 and sterna 6 and7divided...... D. intermedia Diagnosis – Facial teeth present, no pollinose spots The diagnosis for the genus given by Feijen (1981) is on tergum 3, average ratio eye span/body now considerably updated. length 77–80%, on the average 9.2–11.1 Small to medium-sized Diopsidae (3.0–5.8 mm) tubercles per femur 1, female tergum 7 and with short eye stalks, average ratio eye span/body sterna6and7undivided...... 3 length varying from 65–80%, sexual homomor- 3. Yellowish brown fly (if alive or fresh), dis- phism with regards to eye span; bipartite arista; IVS tal 3 tarsomeres of front leg pale yellowish, and OVS strong; prosternum basiliform; no supra- ratio scutellar spine/scutellum ∼ 2.4, fe- alar spines; scutellum convex, deeper than long with male sternum 8 not constricted, mesad side curved spines, central section of spines dark, base and of surstylus concave, inner side of sursty- tip pale; strong apical setae with average size varying lus with microtrichia on apical and mesad from 0.4–1.2 times the scutellar spine length, scutal quarter...... D. africana setae present or absent; femur 1 moderately incras- – Dark reddish brown fly (if alive or fresh), sate with two rows of 2 to 12 tubercles and with- distal 3 tarsomeres of front leg dark brown, out spine-like setae; apical spurs of femora 2 and 3 ratio scutellar spine/scutellum ∼ 2.8, fe- present or absent; irrorated dark wings with subapi- male sternum 8 U- to V-shaped, mesad side cal band of three pale spots, centrally one anterior of surstylus convex, inner side of surstylus and one posterior spot, subbasally one anterior and with microtrichia only near mesad edge . . . one posterior spot, no alula, vein A1 not extending ...... D. kwaipai past cell cup, vein CuA1 not reaching margin; ab- 4. Glabrous or very moderately hairy with domen strongly clavate, small and equal-sized terga short setulae, scutal setae present or absent, 1 & 2, large & broad terga 3 & 4, seams visible discal scutellar setae absent, facial teeth ab- in syntergum 1 + 2 + 3; sterna 1, 2 and 3 glossy; sent, abdominal sterna 1–3 glossy and 4– spiracle 1 in tergum; three smooth, round to egg- 5 (thinly) pollinose, female tergum 7 and shaped, spermathecae; sclerotised ‘ring’ almost rect- sterna 6 and 7 divided (at least in D. schul- angular with very slender arms and well sclerotised; teni), surstylus rounded to fan-shaped ...... 5 male sternum 6 horseshoe- to circle-shaped or con- – Moderately hairy with long setulae, scutal sisting of two fragments; epandrium with a rounded- setae present, discal scutellar setae present, triangular shape, surstyli simple (no clear apophysis), facial teeth present or absent, abdominal processus longi smooth and slender, running in a sterna 1–5 glossy, female tergum 7 and curved way between surstyli. sterna 6 and 7 single, surstylus with subapi- calapodemeorclub-shaped...... 6 5. Glabrous, no scutal scutellar setae, length Key to species of Diopsina of scutellar spines about 0.4 mm (∼1.4 1. Very hairy (Figs 1, 3), no scutal or discal times scutellum), width of central anterior setae, scutellar spine > 19% of body length, wing spot narrowing towards the wing edge average length of apical seta 49–57% of and there about half its height (Fig. 48), scutellar spine, on the average 7.7–11.1 no apical spurs on femora 2 & 3, surstylus tubercles per femur 1, average ratio eye triangular to fan-shaped (Figs 50–51) . . . . . span/body length 72–80%, female tergum ...... D. schulteni 8notfullydivided...... D. africana-group 2 – Very moderately hairy, three pairs of scu- – Moderately hairy with scutal setae (Figs 10– tal setae, length of scutellar spines about 11) or glabrous without scutal setae 0.5 mm (∼1.9 times scutellum), width of (Fig. 46), scutellar spine < 15% of body central anterior wing spot broadening to- length, average length of apical seta 71– wards the wing edge and about equal to 121% of the scutellar spine, on the aver- its height (Fig. 19), tiny but distinct apical age 13.9–16.7 tubercles per femur 1, aver- spurs on femora 2 & 3, surstylus rounded age ratio eye span/body length 64–67%, fe- to somewhat angular – depending on view (Figs 28–29) ...... D. fluegeli sp. n.

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6. Facial teeth present, always normal wings, seta, scutellar spines almost 2.5 times scutellum, apical seta shorter than scutellar spine, two rather short apical seta (0.5 times the scutellar spine), pollinose spots on tergum 3, female sterna 7 front femora with on the average 9.1 (female) and and 9 not constricted, spermathecae round, 9.4 (male) tubercles, pale distal 3 tarsomeres of front surstylus with broad, hump-like subapical leg, no pollinose spots on tergum 3, female sterna 6 apodeme in posterior view ...... D. nitida and 7 undivided, female sternum 8 not constricted, – Facial teeth absent, often brachypterous, broad, spade-like surstyli with concave mesad side, apical seta longer than scutellar spine, no male sternum 6 consisting of two fragments, average pollinose spots on tergum 3, female ster- ratio eye span/body length 80% in female and 78% num 7 H-shaped and sternum 8 mesally in male. strongly constricted, spermathecae egg- Distribution. Burundi, Cameroon, Democratic Re- shaped, surstylus slender, club-shaped . . . . public of Congo, Ethiopia, Ivory Coast, Uganda ...... D. draconigena (holotype). Measurements (including material studied by Feijen Note: Below, in the descriptions of the six already (1984)). Body length 5.0 mm ± SE 0.1 (range 3.4– known species only new or updated information (as 5.8, n = 29), 5.2 mm ± 0.1 (range 3.8–6.4, n = compared to Feijen 1981, 1984) is given. 33); eye span 4.0 mm ± 0.1 (range 2.8–4.6, n = 29), 4.0 mm ± 0.1 (range 3.0–4.8, n = 33); wing Diopsina africana (Shillito) length 3.7 mm ± 0.1 (range 2.6–4.3, n = 29), ± = Figs 1–9 3.9 mm 0.1 (range 2.7–4.7, n 33); length of scutellar spine 1.08 mm ± 0.02 (range 0.72–1.24, Cyrtodiopsis africana Shillito, 1940: 160. n = 29), 1.07 mm ± 0.02 (range 0.75–1.25, n = Diopsina ferruginea Lindner 1962: 17. 33). Diopsina africana Feijen 1978: 23; Feijen 1981: 468; Feijen 1984: 19. Habitus. The photograph in lateral view (Fig. 1) gives a good presentation of the relative proportions Material studied. Burundi,1, hill nr Bujumbura, and shape of head, thorax, abdomen, wings and 25.vii.1986, G.G.M. Schulten (RMNH); Camer- legs. The typical hairiness in combination with the oon, Nkolbison (4°0 N 11°30 E), Yaounde, 2,2, absence of scutal setae is shown in Figs 1, 3. 2.viii.1963, 2,3, 6.viii.1963, 3 1.x.1963, 2 Head. Hairiness, shape and size of OVS and IVS 26.x.1963, L. Seegers (ZSM, in total 33 specimens can be seen in Figs 1–3. Eye span small in female of this location); 1,Prov.Adamaoua,S.Dibi,SE (20% shorter than the length of body) as well as Ngaoundéré, 7°7 57 N:13°41 40 E, 1162 m, 2006, in male (22% shorter than the length of body); a F. Menzel (ZSM); Uganda,1, Kasese distr., 11 km clear homomorphic species, rate of dimorphism D = WNW Kasese, eastern foot of the Ruwenzori moun- −0.08 (Fig. 5, Table 1). tain range, NW above Kilembe village, brook and Thorax. Ratio scutellar spine/scutellum in female large swamp, 0°13 18 N 29°59 24 E, 23.iii.2012, 2.54 ± SE 0.05 (n = 10) and in male 2.32 ± 0.05 1555 m, M. von Tschirnhaus (RMNH); 3, Kaba- (n = 14), ratio scutellar spine/body length in female role distr., crater landscape WNW of Fort Por- 0.217 ± 0.003 (n = 29) and in male 0.205 ± 0.003 tal, secondary forest along a brook and cattle pas- (n = 33) (see Table 2); apical seta (Fig. 3, Table 2) tures, swamp vegetation in shade, Impatiens, Acan- almost exactly half the length of the scutellar spine, thus, Cyperus, 0°40 40 N 30°13 30 E, 13.iii.2012, 0.50 ± SE 0.02 times in female (range 0.43–0.57, 1555 m, M. von Tschirnhaus (RMNH & FBUB); n = 7) and 0.51 ± 0.03 times in male (range 0.42– 1,3, Kasese distr., 17 km WNW Kasese, east- 0.64, n = 8). ern foot of Ruwenzori mountain range, near vil- Wing. Wing pattern is shown in Fig. 4. lage Nyakalengrja, swamp around a water reser- Legs. Femur 1 slender in female, ratio of length/ voir with dense Cyperaceae vegetation, 0°20 40 N ± = width 5.1 0.1 (range 4.5–5.5, n 9) and moder- 30°02 22 E, 21.iii.2012, 1630 m, M. von Tschirn- ately incrassate in male, ratio of length/width 4.5 ± haus (RMNH & FBUB). 0.1 (range 3.9–5.5, n = 12), two rows of tubercles on Diagnosis. Diopsina africana gives its name to the distal ﬁfth, inner row in female with 4.7 ± 0.1 tuber- africana-group of the genus (see Feijen 1984) and cles (range 3–7, n = 58) and in male with 5.0 ± 0.1 can be recognised by its yellowish brown colour, tubercles (range 3–7, n = 64), outer row in female large size (mean body length > 5 mm), strong with 4.4 ± 0.1 tubercles (range 3–6, n = 58) and in hairiness (Figs 1, 3), facial teeth, long IVS (4 times male with 4.4 ± 0.1 tubercles (range 3–6, n = 64); stalk diameter), smaller OVS (twice stalk diameter), femora 2 and 3 with quite strong apical spurs. glossy scutum, anterior dorsal section of scutellum Preabdomen. Sternum 1 trapezoid, sternum 2 bell- pollinose, absence of scutal setae and discal scutellar shaped, sternum 3 broadening posteriorly, sternum

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Figs 1–4. Diopsina africana, female, Cameroon, Nkolbison, 2.viii.1963. – 1, habitus, lateral view; 2, head, anterior view; 3, head and thorax, dorsolateral view; 4, wing, dorsal view. Figure 1 scale bar = 1 mm, other Figs scale bars = 0.5 mm.

4 more or less rectangular with rounded corners dicated this concave margin for D. africana and the (Fig. 6); sterna mostly glossy. convex margin for D. kwaipai in his key to the Female postabdomen. Sclerotised ‘ring’ of ventral species, but, by mistake, switched the adjectives con- vagina wall (Fig. 9) a slightly constricted rectangle cave and convex in the respective species descriptions. formed by narrow rods. Laboulbeniales. Two females and one male from Male postabdomen. Sternum 5 consisting of two well Uganda were infected with Rhizomyces sp. (see the separated sclerites, anteriorly rounded and posteri- notes on the ecology of Diopsina below). Next to orly with rather angular corners (Fig. 7), anterior Stigmatomyces feijenii Rossi this is the second Laboul- edges more sclerotised and almost forming a bridge beniales known from Diopsina africana. between the two sclerites, on the meson a very vague sclerotised patch; sternum 6 consisting of two nar- Diopsina draconigena Feijen row, well separated fragments which include the an- Figs 10–17 terior tiny setulae, so the fragments represent anterior sections of sternum 6 (Figs 7–8); surstylus with Diopsina draconigena Feijen, 1981: 469; Feijen 1984: 21; concave mesad margin – Feijen (1984) correctly in- Kotrba et al. 2010: 296.

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Fig. 5. Diopsina africana, eye span plotted against body length.

Material studied. Theoriginaltypeseriesincluded, 12); eye span 2.3 mm ± 0.1 (range 2.0–2.7, n = besides some paratypes from Lesotho and from two 12), 2.2 mm ± 0.0 (range 2.0–2.4, n = 12); other localities in South Africa, holotype, 4 and wing length brachypterous 1.4 mm ± 0.1 (range 5 paratypes from South Africa, KwaZulu-Natal, 0.9–1.9, n = 10), non-brachypterous 2.4 mm Giant’s Castle Reserve, Drakensberg, 18–23.ix.1963. (range 2.3–2.4, n = 2), brachypterous 1.5 mm ± B. & P. Stuckenberg. Now an additional 5 and 0.0 (range 1.1–1.7, n = 10), non-brachypterous 5 with the same Drakensberg collection data were 2.1 mm (range 2.0–2.2; n = 2); length of scutellar studied. spine 0.36 mm ± 0.02 (range 0.29–0.50, n = 12), Diagnosis. Diopsina draconigena belongs to the D. ni- 0.33 mm ± 0.01 (range 0.26–0.42, n = 12). tida-group (see Feijen 1984) and can be recognised Habitus. The photographs in dorsal and lateral view by its small size (with means of 3.4 mm in male and (Figs 10–11) show the striking brachypterous wings 3.5 mm in female it is the smallest of all Diopsina, and also some of the setae. in fact the smallest of all Diopsidae), dark colour, ab- Head. Setae and setulae can be seen in Figs 10–12. sence of facial teeth, relatively moderately-sized IVS Eye span very small in female as well as in male (twice stalk diameter), small OVS (just longer than (respectively 34.4 ± 0.7% and 34.9 ± 0.6% shorter stalk diameter), presence of small head setae (be- than length of body); a clear homomorphic species, sides IVS and OVS), glossy scutum, dorsally polli- rate of dimorphism D = 0.07 (Fig. 13, Table 1). nose scutellum, presence of 3 or more pairs of scutal Thorax. Ratio scutellar spine/scutellum in female setae and 1 or 2 pairs of discal scutellar setae, scutel- 1.91 ± SE 0.05 (n = 7) and in male 1.84 ± 0.02 lar spines twice scutellum, long apical seta (1.2 times (n = 5), ratio scutellar spine/body length in female the scutellar spine), front femora with on the average 0.101 ± 0.003 (n = 14) and in male 0.097 ± 0.003 14.1 (female) and 13.9 (male) tubercles, abdomen (n = 12) (see Table 2). Feijen (1981) described the without pollinose spots, club-like bald surstyli, male apical seta with “as long as spine”. In fact, the apical sternum 6 consisting of two fragments, egg-shaped seta (Fig. 10–11, Table 2) is distinctly longer than spermathecae, average ratio eye span/body length the scutellar spine, 1.20 ± SE 0.04 times in female 66% in female and 65% in male. The occurrence of (range 1.07–1.39, n = 7) and 1.21 ± 0.06 times in a brachypterous form in this species is unique for the male (range 1.07–1.33, n = 5). Diopsidae. Wing. Wing pattern of the brachypterous wing is Distribution. Lesotho, South Africa (holotype). shown in Figs 10–11. The type series of 14 speci- Measurements (including material studied by Feijen mens counted 10 brachypterous ﬂies. The additional (1981)). Body length 3.5 mm ± SE 0.1 (range 3.0– 10 specimens now studied and the single specimen 4.1, n = 12), 3.4 mm ± 0.0 (range 3.1–3.6, n = studied by Kotrba et al. (2010) were all brachypter-

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Figs 6–9. Diopsina africana, Cameroon, Nkolbison. 6–8, male, 26.x.1963. – 6, abdomen, segments 1–4, ventral view; 7, sterna 5 and 6, ventral view; 8, sternum 6 detail, ventral view; 9, female, 1.x.1963, sclerotised ring; Fig. 6 scale bar = 0.2 mm, other Figs scale bars = 0.1 mm.

Table 1. Mean trait size for eye span, body length, wing and scutellar spine in mm (±SE) of the seven Diopsina species. Allometric slope (±SE) is the least-squares regression slope of eye span on body length. The dimorphism column gives the difference between male allometry and female allometry. N refers to the number of pairs determining the allometric slope.

Diopsina Sex N Eye span Body length Wing Scutellar spine Allometric slope Dimorphism africana-group africana 29 4.0 ± 0.1 5.0 ± 0.1 3.7 ± 0.1 1.08 ± 0.02 0.76 ± 0.05 −0.08 33 4.0 ± 0.1 5.2 ± 0.1 3.9 ± 0.1 1.07 ± 0.02 0.68 ± 0.05 intermedia 3 3.5 ± 0.2 4.9 ± 0.3 3.5 ± 0.2 0.95 ± 0.05 0.50 ± 0.29 – kwaipai 16 3.7 ± 0.1 4.7 ± 0.1 3.4 ± 0.1 1.07 ± 0.02 0.70 ± 0.06 0.03 17 3.7 ± 0.1 4.8 ± 0.1 3.4 ± 0.1 1.02 ± 0.02 0.73 ± 0.05 nitida-group ∗ draconigena 12 2.3 ± 0.1 3.5 ± 0.1 1.4 ± 0.1 0.36 ± 0.02 0.52 ± 0.07 0.07 ∗∗ 12 2.2 ± 0.0 3.4 ± 0.0 1.5 ± 0.0 0.33 ± 0.01 0.59 ± 0.13 ﬂuegeli sp. n. 1 2.4 3.7 2.6 0.49 – – nitida 29 2.9 ± 0.1 4.4 ± 0.1 3.1 ± 0.1 0.63 ± 0.01 0.63 ± 0.05 −0.03 33 2.9 ± 0.1 4.5 ± 0.1 3.2 ± 0.0 0.64 ± 0.01 0.60 ± 0.03 schulteni 7 2.6 ± 0.1 3.8 ± 0.1 2.7 ± 0.1 0.40 ± 0.01 0.67 ± 0.12 −0.13 7 2.4 ± 0.1 3.7 ± 0.1 2.6 ± 0.0 0.40 ± 0.01 0.54 ± 0.07

∗ ∗∗ Non-brachypterous form 2.4 mm, non-brachypterous form 2.1 mm.

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Table 2. Ratio (±S.E.) for the seven Diopsina species for length of apical bristle/scutellar spine, length of scutellar spine/body length and length of scutellar spine/length of scutellum.

Diopsina Female Male Female & male Female & male N Apical bristle/ N Apical bristle/ N Scutellar spine/ N Scutellar spine/ scutellar spine scutellar spine body length scutellum africana-group africana 7 0.50 ± 0.02 8 0.51 ± 0.03 62 0.211 ± 0.002 24 2.41 ± 0.04 intermedia 1 0.57 3 0.196 ± 0.014 1 2.30 kwaipai 11 0.49 ± 0.01 14 0.50 ± 0.01 33 0.221 ± 0.002 33 2.80 ± 0.02 nitida-group draconigena 7 1.20 ± 0.04 5 1.21 ± 0.06 26 0.099 ± 0.002 12 1.88 ± 0.03 ﬂuegeli sp. n. 1 0.71 1 0.133 1 1.86 nitida 7 0.87 ± 0.03 4 0.79 ± 0.01 61 0.143 ± 0.002 22 2.24 ± 0.03 schulteni 2 0.83 ± 0.03 1 0.81 13 0.107 ± 0.002 9 1.43 ± 0.04

Figs 10–12. Diopsina draconigena, South Africa, Giant’s Castle Reserve, 18–23.ix.1963. – 10, male, habitus, dorsal view; 11, female, habitus, lateral view; 12, female, head, anterior view; scale bars = 0.5 mm. ous, raising the percentage of the brachypterous form outer row in female with 6.9 ± 0.2 tubercles (range for the known specimens to 84%. 5–8, n = 23) and in male with 7.0 ± 0.2 tubercles Legs. Femur 1 moderately incrassate in female, ra- (range 5–10, n = 22); no apical spurs on femora 2 tio of length/width 4.1 ± 0.1 (range 3.8–4.3, and 3. n = 7) and moderately incrassate in male, ratio of Preabdomen. All sterna glossy. length/width 4.0 ± 0.0 (range 3.9–4.1, n = 5), two Female postabdomen. Sclerotised ring almost quad- rows of tubercles on distal third, inner row in female rangular, but slightly tapering towards the anterior with 7.2 ± 0.2 tubercles (range 6–9, n = 23) and in side (Fig. 17). male with 6.9 ± 0.2 tubercles (range 5–9, n = 22),

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Fig. 13. Diopsina draconigena, eye span plotted against body length.

Figs 14–17. Diopsina draconigena, South Africa, Giant’s Castle Reserve, 18–23.ix.1963. – 14, male, sterna 5 and 6, ventral view; 15, male, sternum 6 detail, ventral view; 16, surstylus, lateral view; 17, sclerotised ring; scale bars = 0.1 mm. Diopsina fluegeli sp. n. Male postabdomen. Surstylus club-shaped in both Figs 18–31 posterior and lateral (Fig. 16) view; sternum 5 a single rectangular plate, the edges less sclerotised, Type material. Holotype (RMNH), Guinea- Bissau, Bissorã Flussaue RGB, Reisfeldbrache (flood the well-sclerotised central rectangle somewhat constricted on the meson (Fig. 14); sternum 6 consist- plain, fallow rice field), 12°12 48 N 15°26 15 W, ing of two fragments, their position (Figs 14–15) to- 6.i.2010, H.-J. Flügel (∼7m). wards the two tiny microchaetae at the original ante- Diagnosis. Diopsina fluegeli belongs to the D. nitida- rior edge of former sclerite clearly indicating that the group of the genus (Feijen 1984) and can be recog- fragments are homologous with the posterior ends of nised by its small size, very moderate hairiness, ab- the horseshoe- to almost circular-shaped sternum 6 sence of facial teeth, long IVS (3 times stalk dia- in the other species of the D. nitida-group. meter), small OVS (1.5 times stalk diameter), glossy brown scutum, almost completely glossy scutellum, presence of three pairs of scutal setae (SA, IA, DC),

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Figs 18–22. Diopsina ﬂuegeli sp. n. holotype, Guinea-Bissau, Bissorã, 6.i.2010. – 18, habitus, dorsal view; 19, wing, dorsal view; 20, head, anterior view; 21, scutellum and abdomen, lateral view (note dorsocentral seta just before pin); 22, scutellum and abdomen, dorsal view; scale bars = 0.5 mm. absence of discal scutellar seta, scutellar spines twice groove brown with roughened surface; face centrally as long as scutellum, medium-sized apical seta (71% with ﬁne horizontal ridges on dorsal half, upper half of scutellar spine length), width of central anterior of face slightly protruding, facial corners rounded, wing spot broadening towards wing edge (at edge no facial teeth (Fig. 20); eye span very small in male about 11% of wing length and equal to height of (35% smaller than the length of body), although the spot), front femora with 13–15 tubercles, one pair of female is not yet known, the species must be ho- pollinose spots on tergum 3, male spiracles 7 in syn- momorphic; stalks glossy brown, broad apical parts sternum 7 + 8, surstyli round to somewhat angular glossy blackish, funiculus brown pollinose; IVS long, (depending on view), surstyli glabrous on outer side 3 times the diameter of the rather broad eye stalk, and with patch of microtrichia on inner side, male base of IVS a small cone, 0.5 times the diameter of sternum 6 horseshoe-shaped, sexual homomorphism the stalk (Fig. 20); OVS small, 1.5 times the diameter with regards to eye span, ratio eye span/body length of the stalk; face with rows of small white setulae, a 0.65 in male. few strong black setulae dorsally near the eye margin. Distribution. Guinea-Bissau. Thorax. Collar glossy brown, only laterally a little bit Measurements. Body length male 3.7 mm (n = 1); of pollinosity, scutum glossy brown (Fig. 18), scutel- eye span male 2.4 mm; wing length male 2.6 mm; lum glossy brown only dorsally a small pollinose tri- length of scutellar spine male 0.49 mm. angle, scutellar spines glossy, on proximal and distal Head. Central part glossy brown, frons slightly third very pale and central third blackish; pleura and darker, ocellar tubercle black; frons (Fig. 18) with sterna glossy brown, only some pollinosity laterally two clear depressions in front of tubercle, depres- near base of abdomen; scutellum convex (Figs 21– sions almost joined on the meson, laterally a ridge 22), short, deeper than long; scutellar spines long, around the frons, touching this ridge small triangular curved upward and outward, diverging under an an- paler brown areas with a roughened surface; arcuate gle of 65°, ratio scutellar spine/scutellum in male

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Figs 23–27. Diopsina ﬂuegeli sp. n. holotype, Guinea-Bissau, Bissorã, 6.i.2010. – 23, abdomen with sterna 1–6, ventral view; 24, base of abdomen, dorsal view; 25, epandrium with surstyli and cerci, posterior view; 26, ejaculatory apodeme and sac, lateral view; 27, synsternum 7 + 8, lateral view; Figs 23–24 scale bars 0.5 mm, other Figs scale bars = 0.1 mm.

Figs 28–31. Diopsina ﬂuegeli sp. n. holotype, Guinea-Bissau, Bissorã, 6.i.2010. – 28, surstylus, lateral view; 29, surstylus, medial view; 30, phallapodeme in situ with synsternum 7 + 8 and epandrium, lateral view; 31, posterior arm of phallapodeme with aedeagus, lateral view; scale bars = 0.1 mm.

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1.9, ratio scutellar spine/body length in male 0.13 section of segment 3 and whole of segment 4 three (see Table 2); metapleural spines well developed, pale times broader than segment 1 (Fig. 23), width of brown pointing laterally; three pairs of scutal setae fifth and subsequent segments diminishing in turn; (SA, IA, DC), a weaker supra-alar seta and strong terga glossy blackish brown, tergum 2 more brownish intra-alar and dorsocentral setae, no discal scutel- anteriorly, only tergum 1 pollinose, tergum 3 with lar seta, apical seta medium-sized, 71% of length of a pair of small pollinose spots anteriorly (Figs 21– scutellar spine, posteriorly directed; scutum with a 22), few whitish setulae on terga, especially laterally, few rows of small white setulae, scutellar spines with posteriorly on tergum 4, and on terga 5; spiracle each about six small setulae on small warts. 1 just in tergum (Fig. 23); sterna 1–3 glossy dark Wing. Irrorated, basal quarter hyaline (except pos- brown, other sterna dark brown and thinly pollinose. teriorly of cell cup), apical eighth weakly infus- Male postabdomen. Sternum 4 and 5 single rectan- cated, remainder of wing darkly infuscated with three gular sclerites; sternum 6 horseshoe-shaped, almost bands of hyaline spots, giving three dark crossbands circular (Fig. 23); synsternum 7 + 8 rather broad (Fig. 19); preapical dark band broad, apical edge mesally, with band-like extension at left side (Figs 27, more or less straight, starting from just before tip of 30); left and right spiracle 7 in synsternum; epan- cell r1, around veins R4 + 5 and M connected to drium (Figs 25, 30) rounded, with about nine pairs infuscated apex, broadly connected to central band of setulae, only covered with microtrichia on poste- in cell r4 + 5 and around vein R4 + 5andveinM; rior edge; surstyli with narrow link to epandrium, in central band about equal in width to preapical band posterior view (Fig. 25) irregularly shaped, rather an- and connected to basal band along vein Cu; basal gular, somewhat pentagonal, in lateral view (Fig. 28) band small anteriorly and widening posteriorly, al- still rather angular, in medial view (Fig. 29) smoothly most complete, only not continuing in cell c; this in- rounded, almost circular, one single small ridge on fuscation pattern creating seven hyaline spots, three posterior part of inner side; surstyli in posterior and between preapical band and apical infuscation, two lateral view glabrous, only microtrichia visible along between central and subapical band (the anterior one inner edge, a few small setulae near distal edge, on in cells r1 and r2 + 3, not reaching vein R4 + 5, inner side a round patch with microtrichiae; surstyli the posterior one basally in cell m) and two between interconnected via long and slender curved proces- basal and central band (the anterior one in cells c, r1 sus longi; cerci rather broad, ratio of length/width and br extending almost halfway into dm, the poste- 2.4, apically acute, covered with microtrichia and a rior one centrally in cell cua1), width of central an- set of long setulae along the edges; phallapodeme terior wing spot broadening towards the wing edge (Figs 30–31) long, anterior arm broad and slightly (at edge about 11% of wing length) and about equal curving downward, posterior arm narrow, strongly to its height (Fig. 19); glabrous basal areas include curving downward and 1.4 times as long as posterior cell c, basal tip op cell r1, basal half of cell br, basal arm; aedeagus rather small and compact; ejaculatory half of cell bm and basal three-quarters of cell cup;in apodeme slender, axe-shaped anteriorly (Fig. 26). addition the section of the proximal anterior hyaline Etymology. This species is named after its collector, spot in cell r1 is glabrous. Mr. Hans-Joachim Flügel of the Lebendiges Bienen- Legs. Front leg with first two segments brown, outer museum in Knüllwald, Germany (www.lebendiges- side glossy, inner side pollinose; front femora glossy bienenmuseum.de). brown with vague darker brown spot on inner side, Remarks. Diopsina fluegeli belongs to the D. nitida- front tibiae and tarsi brown; mid- and hind legs yel- group which also includes D. nitida, D. schulteni and lowish brown, femora 2 and 3 with dark brown band D. draconigena. Within this group, it comes closest on distal third, femora also with small vague spot in to D. schulteni. the middle, tibia 3 with dark brown bands proxi- mally and distally; femur 1 (Fig. 18) moderately in- Diopsina intermedia Feijen crassate in male (ratio of length/width 4.6), tubercles Fig. 56 on distal third, inner row in male with 8.5 tubercles (range 8–9, n = 2), outer row in male with 5.5 tuber- Diopsina intermedia Feijen, 1984: 22. = cles (range 5–6, n 2); femur 1 with some setulae Type series. Thetypeseriesconsistsonlyofthree ventrally; femora 2 and 3 with tiny but distinct apical female from the Democratic Republic of Congo spurs. and no new material has become available. Here, Preabdomen. strongly clavate; syntergum involving the diagnosis and the biometrical information are terga 1–3 (as in all Diopsina), seam between terga updated. 1 and 2 just visible, suture between terga 2 and 3 Diagnosis. Diopsina intermedia belongs to the D. very distinct (Fig. 24); segment 1 slender, segment africana-group (Feijen 1984) and can be recognised 2 also slender but apically extended laterally, distal

Downloaded from Brill.com09/23/2021 11:40:06PM via free access Feijen & Feijen: The genus Diopsina Curran 173 by its small size, strong hairiness, absence of facial The graphic representation (Fig. 56) of eye span teeth, long IVS (3 times stalk diameter), moderately- against body length shows D. intermedia again as sized OVS (twice stalk diameter), glossy yellow- intermediate between D. africana and D. kwaipai on ish brown scutum, absence of scutal setae, dorsally the one side and the species of the D. nitida-group pollinose scutellum, scutellar spines 2.5 times scutel- on the other side. lum, rather short apical seta (0.57 times the scutel- Thorax. Ratio scutellar spine/scutellum in female 2.3 lar spine), front femora with on the average 7.7 (n = 1), ratio scutellar spine/body length in female tubercles, one pair of pollinose spots on tergum 3, 0.196 ± 0.014 (n = 3) (see Table 2); the apical seta reduced, irregularly shaped, tergum 7 in female, di- is slightly longer than half the scutellar spine (57%, vided tergum 7 and sterna 6 and 7 in female, sin- n = 1). gle, mesally hardly constricted tergum 8 in female, Legs. Femur 1 with two rows of tubercles on distal round spermathecae, and average ratio eye span/body quarter, inner row in female with 4.2 ± 0.3 tubercles length 72% in female. (range 3–5, n = 6), outer row in female with 3.5 ± Distribution. Democratic Republic of Congo. 0.4 tubercles (range 2–5, n = 6). Measurements. Body length 4.9 mm ± SE 0.2 = ± (range 4.3–5.2, n 3); eye span 3.5 mm 0.1 Diopsina kwaipai Feijen (range 3.2–3.8, n = 3); wing length 3.5 mm ± 0.2 Figs 32–37 (range 3.2–3.8, n = 3); length of scutellar spine 0.95 mm ± 0.05 (range 0.88–1.05, n = 3). Diopsina kwaipai Feijen, 1981: 474; 1984: 26. Head. Eye span very small in female: 28.4 ± 2.2% Type series. The type series consists of 21 males and shorter than length of body; although the male is 18 females from Malawi and no new material has not yet known, the species must be homomorphic.

Figs 32, 33. Diopsina kwaipai, Malawi, Zomba, 3.vii.1975, female paratype. – 32, head, anterior view; 33, wing, dorsal view; scale bars = 0.5 mm.

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Fig. 34. Diopsina kwaipai, eye span plotted against body length.

Figs 35–37. Diopsina kwaipai. – 35–36, male paratype, Malawi, Zomba, 12.vii.1975; 35, sterna 5–6 and synsternum, ventral view; 36, sternum 6 detail, ventral view; 37, female paratype, Malawi, Zomba, sclerotised ring; scale bars = 0.1 mm. become available. As the original measurements were just less than 5 mm), strong hairiness, strong facial lost, the body length, eye span, wing length, length teeth (Fig. 32), long IVS (4.5 times stalk diameter), of scutellar spine and length of apical seta were re- smaller OVS (twice stalk diameter), glossy scutum, measured, while also the number of tubercles on the anterior dorsal section of scutellum pollinose, ab- front femora were recounted. sence of scutal setae and discal scutellar seta, scutel- Diagnosis. Diopsina kwaipai belongs to the D. afri- lar spines almost 3 times scutellum, rather short api- cana-group of the genus (Feijen 1984) and can be cal seta (0.5 times the scutellar spine), front femora recognised by its dark reddish brown (while alive al- with on the average at least 10.0 (female) and 11.1 most blackish) colour, large size (mean body length (male) tubercles, dark brown distal 3 tarsomeres of

Downloaded from Brill.com09/23/2021 11:40:06PM via free access Feijen & Feijen: The genus Diopsina Curran 175 front leg, no pollinose spots on tergum 3, female ter- tised, posteriorly strongly constricted on the meson gum 7 and sterna 6 and 7 undivided, female sternum (Fig. 35); sternum 6 consisting of two narrow, well 8 strongly constricted, broad, spade-like surstyli with separated fragments which include the anterior tiny convex mesad side, male sternum 6 consisting of two setulae, so the fragments represent anterior sections fragments, average ratio eye span/body length 78% of sternum 6 (Figs 35–36); spiracles 7 in synsternum in female and 77% in male. 7 + 8; surstylus with convex mesad margin. Distribution. Malawi. ± Measurements. Body length 4.7 mm SE 0.1 Diopsina nitida (Adams) (range 4.1–5.2, n = 16), 4.8 mm ± 0.1 (range Figs 38–45 4.0–5.3, n = 17); eye span mm 3.7 ± 0.1 (range 3.3–4.0, n = 16), 3.7 mm ± 0.1 (range 3.1– Teleopsis nitida Adams, 1903: 46. 4.1, n = 17); wing length 3.4 mm ± 0.1 (range Diopsina ferruginea Curran, 1928a: 5; Curran 1928b: 183; nec 3.0–3.8, n = 15), mm 3.4 ± 0.1 (range 2.7– Shillito 1940: 153, 155; (in part) van Bruggen 1961: 429; 4.0, n = 17); length of scutellar spine 1.07 mm ± nec Lindner 1962; Feijen 1978: 22; Feijen 1981: 473. = ± Phryxodiopsis kaeleana Séguy, 1955: 1106; Roy 1963: 966. 0.02 (range 0.96–1.18, n 16), 1.02 mm 0.02 Diopsina nitida Feijen, 1978: 22 (incl. Diopsina kaeleana); (range 0.82–1.16, n = 17). ± Feijen 1981: 47; Feijen 1984: 27. Head. The eye span is small in female (21.8 0.3% Diopsina kaeleana Cogan & Shillito 1980: 585; Feijen 1981: shorter than the length of body) as well as in male 474, 482. (22.6 ± 0.4% shorter than the length of body); a Diopsina sp.; Feijen 1981: 479. = clear homomorphic species, rate of dimorphism D 0.03 (Fig. 34, Table 1). Material studied. D.R. Congo (Zaire), 1 , Lubum- bashi, vii.1969, light trap, E. Bouvy (RMNH); Thorax. Ratio scutellar spine/scutellum in female 2.84 ± SE 0.03 (n = 16) and in male 2.77 ± 0.03 1 , Lubumbashi, ix.1969, light trap, E. Bouvy (RMNH); Togo,1, Région des Plateaux: Koug- (n = 17), ratio scutellar spine/body length in female ± = ± nohou, at river Kpon, 7°41 22 N 0°47 44 E, 23.iv. 0.228 0.002 (n 16) and in male 0.215 0.003 (n = 17) (see Table 2); apical seta (see Table 2) almost 2008, 560 m, M. von Tschirnhaus (FBUB); 1 ,Ré- exactly half the length of the scutellar spine, 0.49 ± gion des Plateaux, Plateau de Danyi, near Dzog- SE 0.01 times in female (range 0.47–0.51, n = 11) bégan, Monastière de l’Ascension, at river/creek and 0.50 ± 0.01 times in male (range 0.44–0.59, Danyi, abandoned plantation ground with 3 domi- nant plants: Eleusine indica (Poaceae), Rhynchelytrum n = 14). repens (Poaceae), Cyperus sp. 7°14 30 N 0°40 45 E, Wing. Wing pattern is shown in Fig. 33. 14.iv.2008, 725 m, M. von Tschirnhaus (RMNH); Legs. Femur 1 moderately incrassate in female, ratio of length/width 4.9 ± 0.0 (range 4.8–5.2, n = Uganda,3 , Kasese distr., Lake Edward N, lonely coast at “Pelican Point”, 7.6 km W of Katwe, 16), and moderately incrassate in male, ratio of length/width 4.6 ± 0.0 (range 4.3–4.9, n = 17), two slightly wet grass vegetation, 0°08 57 S 29°49 05 E, 25.iii.2012, 915 m, M. von Tschirnhaus & F. rows of tubercles on distal fifth, inner row in female with 5.2 ± 0.1 tubercles (range 4–6, n = 30) and Menzel (RMNH & FBUB); 4 ,Bushenyidistr., in male with 5.6 ± 0.1 tubercles (range 4–6, n = Kazinga Channel SE of Katunguru, road side S of the road bridge, along Papyrus swamp, Lantana, 29), outer row in female with 4.8 ± 0.1 tubercles (range 3–6, n = 30) and in male with 5.5 ± 0.1 Convolvulaceae, Poaceae, 0°07 45 S 30°03 09 E, = 26.iii.2012, 925 m, M. von Tschirnhaus (RMNH tubercles (range 4–7, n 29); femora 2 and 3 with quite strong apical spurs. Feijen (1984) indicated 5.7 &FBUB);1 , Kasese distr., saltwater-crater Lake Katwe, Queen Elizabeth National Park, at NE tubercles for both inner row and outer row in both end of Lake Edward, NW of Katwe, 0°08 07 S sexes. Unfortunately both SE and number of flies counted were not given. If the counts were made 29°52 17 E, 25.iii.2012, 888 m, swamps and shores from the fresh flies and from all specimens it is with salt production, Juncus, Scirpus, Hydrocotyle,M. likely that the number of tubercles is slightly higher von Tschirnhaus & F. Menzel (RMNH). than now given. Anyway, given the (geographic) Diagnosis. Diopsina nitida gives its name to the D. variation in number of tubercles in other Diopsina, nitida-group of the genus. It can be recognised by the numbers of tubercles should not be used in the its small size (though clearly the largest within its key to the species (as in Feijen 1984). group), dark reddish-brown colour, moderate hairiness, presence of small facial teeth, long IVS (4 times Preabdomen. Sterna mostly glossy. stalk diameter), smaller OVS (twice stalk diameter), Female postabdomen. Sclerotised ‘ring’ an almost perfect rectangle formed by narrow rods (Fig. 37). presence of small head setae (besides IVS and OVS), glossy scutum (though some specimens with polli- Male postabdomen. Sternum 5 consisting of a single sclerite, anterior and lateral edges more sclero- nose scutum are known), dorsally pollinose scutel-

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Figs 38–40. Diopsina nitida. 39–40, female, D.R. Congo, PNG, 22.viii.1952. – 38, habitus, dorsolateral view; 39, head and thorax, dorsal view; 40, female, Malawi, Bunda, 15.iv.1975, wing, dorsal view; scale bars 0.5 = mm.

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Fig. 41. Diopsina nitida, eye span plotted against body length. lum, presence of 3 or more pairs of scutal setae and 1 (n = 13), ratio scutellar spine/body length in female or 2 pairs of discal scutellar setae (Figs 38–39), scutel- 0.142 ± 0.003 (n = 28) and in male 0.144 ± 0.002 lar spines about 2.3 times scutellum, medium-sized (n = 33) (see Table 2); apical seta (Figs 38–39, Ta- apical seta (about 80% of scutellar spine length), ble 2) more than three-quarters the length of scutellar width of central anterior wing spot hardly broaden- spine, 0.87 ± SE 0.03 times in female (range 0.75– ing towards wing edge, front femora with on the av- 1.00, n = 7) and 0.79 ± 0.01 times in male (range erage 15.7 (female) and 16.4 (male) tubercles, one 0.77–0.80, n = 4). pair of pollinose spots on third tergite, surstyli with Wing. In most specimens no continuation of proxi- hump-like subapical apodeme in posterior view (not mal anterior wing spot into cell bm, width of central in lateral view), male sternum 6 horseshoe-shaped, anterior wing spot hardly broadening towards wing round spermathecae, average ratio eye span/body edge (Fig. 40). length 65% in female and 64% in male. Legs. Femur 1 moderately incrassate in female, ratio Distribution. Angola, Cameroon, Democratic Re- of length/width 4.6 ± 0.1 (range 3.8–5.3, n = public of Congo, Malawi, Nigeria, Senegal, Togo, 10), and moderately incrassate in male, ratio of Uganda, Zambia, Zimbabwe (holotype). length/width 4.5 ± 0.1 (range 4.1–5.5, n = 13), two Measurements (including material studied by Feijen rows of tubercles on distal half, inner row in female (1981)). Body length 4.4 mm ± SE 0.1 (range 3.6– with 8.4 ± 0.2 tubercles (range 6–12, n = 54) and 4.9, n = 29), 4.5 mm ± 0.1 (range 3.4–5.2, n = in male with 9.1 ± 0.2 tubercles (range 6–12, n = 33); eye span 2.9 mm ± 0.1 (range 2.3–3.2, n = 54), outer row in female with 7.4 ± 0.2 tubercles 29), 2.9 mm ± 0.1 (range 2.0–3.2, n = 33); wing (range 5–11, n = 54) and in male with 7.6 ± 0.2 length 3.1 mm ± 0.1 (range 2.3–3.5, n = 28), tubercles (range 5–10, n = 54);femora2and3with 3.2 mm ± 0.1 (range 2.4–3.7, n = 32); length of small apical spurs. scutellar spine 0.63 mm ± 0.02 (range 0.46–0.77, Preabdomen. Spiracle 1 well in tergum (Fig. 42). All n = 28), 0.64 mm ± 0.02 (range 0.46–0.80, n = sterna glossy. 33). Female postabdomen. Sclerotised ‘ring’ an almost Head. Eye span is very small in female (35.5 ± perfect rectangle formed by narrow rods (Fig. 45). 0.5% shorter than length of body) as well as in Male postabdomen. Sternum 4 a single rectangular male (36.3 ± 0.4% shorter than length of body); a sclerite, laterally more sclerotised (Fig. 42); sternum clear homomorphic species, rate of dimorphism D = 5 two rectangular sclerites, narrowly separated on −0.03 (Fig. 41, Table 1). the meson; sternum 6 somewhat horseshoe-shaped Thorax. Ratio scutellar spine/scutellum in female (Fig. 42); synsternum 7 + 8 a slender sclerite; left 2.22 ± SE 0.05 (n = 9) and in male 2.25 ± 0.03 and right spiracle 7 in synsternum (Fig. 42); surstyli

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Figs 42–45. Diopsina nitida. – 42–44, male, D.R. Congo, Lubumbashi, vii.1969; 42, abdomen with sterna 1–6 and synsternum 7 + 8, ventral view; 43, epandrium with surstyli and cerci, posterior view; 44, surstylus, lateral view; 45, female, Nigeria, Zaria, 27.ii.1970, sclerotised ring; Fig. 42 scale bar = 0.2 mm, other Figs scale bars = 0.1 mm. with hump-like subapical apodeme in posterior view Laboulbeniales. Two males were infected by a Rhi- (see Fig. 43 and Feijen 1981, 1984), however, in lat- zomyces sp. This is the first fungal parasite known for eral view the surstylus is rather rectangular and api- this fly species. cally somewhat rounded while the apodeme is then not visible (Fig. 44), in lateral view surstylus with Diopsina schulteni Feijen some sparse setulae and inner third with microtrichia Figs 46–54 (Fig. 44). Remarks. The puzzling variation in pollinosity pat- Diopsina schulteni Feijen, 1978: 20; Feijen 1981: 479; Feijen tern of the scutum, reported by Feijen 1981, was re- 1984: 29. examined. The two Malawi males have a pollinose Material studied. Central African Republic,2 ,5 , scutum, while all other specimens have a glossy scu- Bambari, 19.iii.1989, G.G.M. Schulten (RMNH); tum. This difference can again be confirmed. Bio- D.R. Congo,1,1 , P.N.A., Massif Ruwenzori, metrical aspects for the two forms were compared. riv. Kamusonge, affl. Lume, 2.ii.1958, 2100 m, P. No significant differences were found with one strik- Vanschuytbroeck (RMNH). ing exception. The front femora of the two Malawi Diagnosis. Diopsina schulteni belongs to the D. ni- specimens were slender (ratio of length/width 5.4 ± tida-group of the genus (see Feijen 1984) and can be 0.1, range 5.3–5.5, n = 2), while in specimens with recognised by its small, compact built, glossy brown a glossy scutum the front femora were moderately in- colour, baldness (Fig. 46), absence of facial teeth crassate (ratio of length/width 4.4 ± 0.1, range 4.1– (Fig. 47), relatively moderately-sized IVS (twice stalk 4.8, n = 11). This issue can only be settled when diameter), small OVS (just longer than stalk diame- more specimens from Malawi become available for ter), glossy scutum, dorsally pollinose scutellum, ab- study. sence of scutal and scutellar setae (except for apical

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Figs 46–48. Diopsina schulteni, Central African Republic, Bambari, 19.iii.1989. – 46, male, habitus, dorsolateral view; 47, female, head, anterior view; 48, male, wing, dorsal view; scale bars = 0.5 mm. setae of scutellar spines), short scutellar spines (al- gards to eye span, average ratio eye span/body length most 1.5 times scutellum), medium-sized apical seta 68% in female and 66% in male. (82% of scutellar spine length),width of central an- Distribution. Central African Republic, Democratic terior wing spot narrowing towards the wing edge (at Republic of Congo, Togo (holotype). edge about 5% of wing length and half the height of Measurements (including material studied by Feijen spot), front femora with on the average 15.0 (female) (1981)). Body length 3.8 mm ± SE 0.1 (range 3.2– and 5.9 (male) tubercles, no apical spurs on femora 4.2, n = 7), 3.7 mm ± 0.1 (range 3.3–3.9, n = 7); 2 and 3, one pair of pollinose spots on tergum 3, eye span 2.6 mm ± 0.1 (range 2.2–2.9, n = 7), female tergum 6 and sterna 6 and 7 all consisting 2.4 mm ± 0.1 (range 2.2–2.6, n = 7); wing length of two elongate sclerites, surstyli triangular to fan- 2.7 mm ± 0.1 (range 2.3–3.1, n = 9), 2.6 mm ± shaped, surstyli mainly glabrous on outer side (with 0.0 (range 2.4–2.7, n = 6); length of scutellar spine one apical corner with of microtrichia) and on inner 0.40 mm ± 0.01 (range 0.36–0.45, n = 8), side with apical half with microtrichia, male sternum 0.40 mm ± 0.01 (range 0.36–0.45, n = 6). 6 horseshoe-shaped to (on inner edges) heart-shaped, Head. The eye span is very small in female (31.9 ± round spermathecae, sexual homomorphism with re- 0.8% shorter than the length of body) as well as in

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Fig. 49. Diopsina schulteni, eye span plotted against body length.

Figs 50–54. Diopsina schulteni, Central African Republic, Bambari, 19.iii.1989. – 50, surstylus, lateral view; 51, surstylus, medial view; 52, male sterna 5–6 and synsternum, ventral view; 53, male sternum (enlarged), ventral view; 54, sclerotised ring; scale bars = 0.1 mm.

Downloaded from Brill.com09/23/2021 11:40:06PM via free access Feijen & Feijen: The genus Diopsina Curran 181 male (33.7 ± 0.5% shorter than the length of body); ble 1). For differences between the species can be re- a clear homomorphic species, rate of dimorphism ferred to Table 1. D =−0.13 (Fig. 49, Table 1). Thorax. Ratio scutellar spine/scutellum in female Scutellum and scutellar spines 1.38 ± SE 0.04 (n = 3) and in male 1.45 ± 0.05 = The scutellar spines are in absolute and relative (as (n 6), ratio scutellar spine/body length in female compared to body length) terms much larger in the 0.107 ± 0.004 (n = 7) and in male 0.108 ± 0.004 = D. kwaipai-group than in the D. nitida-group (Ta- (n 6) (Table 2); apical seta (Fig. 46, Table 2) more bles 1 and 2). In the D. kwaipai-group the differences than three-quarters the length of the scutellar spine, in ratio scutellar spine/body length are very small, 0.83 ± SE 0.03 times in female (range 0.80–0.87, = = but in the ratio scutellar spine/scutellum a distinct n 2) and 0.81 times in male (n 1). difference exists between D. africana and D. kwaipai Wing. Width of central anterior wing spot (Fig. 48) with respectively 2.41 ± 0.04 and 2.80 ± 0.02. In narrowing towards the wing edge, width of this spot the D. nitida-group the differences for the two ratios at wing edge about 5% of wing length and about half are larger (Table 2). For both ratios the highest score the height of the spot. is for D. nitida. For the ratio scutellar spines/body Legs. Femur 1 incrassate in female, ratio of length/ length D. draconigena and D. schulteni have the low- width 4.0 ± 0.2 (range 3.8–4.4, n = 3), and incras- ± est score. For the ratio scutellar spine/scutellum D. sate in male, ratio of length/width 4.0 0.1 (range schulteni has by far the lowest score. Especially the 3.8–4.4, n = 6), two rows of tubercles on distal third, ± ratio scutellar spine/scutellum is a useful diagnostic inner row in female with 8.6 0.3 tubercles (range character. 7–12, n = 15) and in male with 9.2 ± 0.2 tubercles (range 8–10, n = 11), outer row in female with 6.4 ± 0.1 tubercles (range 6–7, n = 15) and in male Inner and outer vertical seta with 6.7 ± 0.2 tubercles (range 5–8, n = 11); femora The IVS is relatively the longest in D. kwaipai, D. 2and3withoutapicalspurs. africana and D. nitida: respectively 4.5, 4 and 4 times Preabdomen. Sterna 1–3 glossy, sterna 4–5 pollinose. the diameter of the eye stalk. In both D. intermedia Female postabdomen. Sclerotised ‘ring’ almost and D. fluegeli sp. n., the IVS is 3 times the stalk dia- square, formed by narrow rods, posterior corners meter, while in both D. draconigena and D. schulteni pointed (Fig. 54). it is twice the diameter. The OVS is twice the diame- Male postabdomen. Sternum 4 and sternum 5 (Fig. ter in D. kwaipai, D. africana, D. intermedia and D. 52) single rectangular sclerites; sternum 6 some- nitida while it is 1.5 times the diameter in D. fluegeli what horseshoe-shaped but anterior section straight sp. n. and equal to the diameter in both D. draconi- and with a triangular median extension (Figs 52– gena and D. schulteni. These two characters figure al- 53) which makes the inner edge of this sclerite ready in many species descriptions for diopsids, but heart-shaped; synsternum 7 + 8 a slender sclerite measuring and averaging larger series appears useful (Fig. 52); left and right spiracle 7 in synsternum in various groups. (Fig. 52); surstyli triangular to fan-shaped (Figs 50– 51), surstyli mainly glabrous on outer side but with Apical seta microtrichia in one apical corner, surstyli on me- So far, the relative length of the apical seta at the tip dian side with microtrichia on apical half, some weak of the scutellar spine has only summarily been in- ridges on posterior edge of inner side (Fig. 51). dicated in descriptions, usually as compared to the length of the scutellar spine and based on a few specimens. Often, the seta is partly or completely bro- Discussion ken off. However, as shown in Table 2, it pays to In this section some Diopsina characters will be place more emphasis on this character and to mea- discussed which have not previously (Feijen 1981, sure larger series if possible. Table 2 is for this char- 1984) been dealt with. The phylogenetic position acter still based on rather small numbers of speci- of the genus Diopsina within its family is also dis- mens per species, but the correlation between val- cussed. The limited information on the ecology of ues for females and males indicates that the data the Diopsina species will be reviewed. are reliable. A significant difference can be seen for this character between the D. africana-group (ra- Body size tio 0.49–0.57) and the D. nitida-group (ratio 0.71– The four species in the D. nitida-group are all smaller 1.21). Diopsina intermedia takes up a somewhat in- than the three species in the D. africana-group (Ta- termediate position with 0.57. Diopsina draconigena is the only Diopsina in which the apical seta is longer than the spine. Long apical setae are the rule in

Downloaded from Brill.com09/23/2021 11:40:06PM via free access 182 Tijdschrift voor Entomologie, volume 156, 2013 the genera Centrioncus Speiser, 1910, Te log lab r u s Fei- sented. The wing sections measured were the central jen, 1983, Sphyracephala Say, 1828 and Cladodiop- width of the large H-shaped band (the combination sis Séguy, 1949. However, in the Diopsinae this seta of the central and subapical bands), the central width is absent in Diopsis and most Eurydiopsis,whilein of the apical infuscation, the width of the basal an- the other genera the seta is always shorter than the terior wing spot at the wing edge and the width of spineexceptforafewspeciesofDiasemopsis Ron- the central anterior wing spot at the wing edge (see dani, 1875. Shillito (1971) tried to use the length of the arrows in Fig. 33). From the data sets and R2 the apical seta as an important differential character values in Fig. 55 can be seen that the variances at- at genus level, but his Table 2 contains a number of tributable to wing length for width of the H-band inaccuracies for this character. Describing this char- and for width of the apical infuscation section are acter in terms of just large, medium or short is not high, while the R2 values for the variance in the wing sufficient, certainly not at species level, as the case of spots attributable to wing length are low. In fact, the the genus Diopsina clearly shows. low variances for the ratios wing spots/wing length might represent cases of hypoallometry, stressing the Wing pattern intraspecific importance of these spots. This in its In Diopsidae, wing pattern is a crucial differential turn emphasises the taxonomic importance of these character at species-, species-group- and genus-level. wing spots. This importance not only resides in the So far, the wing pattern has mainly been described pattern (shape and size) of spots and bands, but also in qualitative terms, indicating spots, bands and in- in the distribution and density of the microtrichia fuscated areas in relation to veins and cells. Pin- patterns. The microtrichia formations result in the pointing differences in superficially similar wing pat- Wing Interference Patterns (WIPs) as discussed by terns is not always easy. Feijen (1989) indicated that Shevtsova et al. (2011). Now that more high-quality the same type of irrorated wing pattern found in photographs of live diopsids become available, the Diopsina canalsobefoundinthegeneraCyrtodiop- importance of these reflective patterns becomes easier sis, Te le op s is , Eurydiopsis, Eurydiopsis Séguy & Van- to visualise. Likewise, these photographs also stress schuytbroeck (nec Frey; see Feijen 1989) and Eosiop- that the pattern of a single stretched wing is impor- sis Feijen, 2008 (as Sinodiopsis Feijen, 1989). Accu- tant, but that patterns arising from overlaying wings rately describing (the differences in) wing patterns is can equally be of importance. difficult in such cases. Illustrations, especially photographs, can to a large extent solve this problem, Biometric analyses but for species diagnoses and for keys, the description In the Diopsidae, biometric data can be very useful to of sections of the wing pattern in quantitative terms separate genera, species-groups and species. The bio- can also be rewarding. In this paper, the differences metrical data used include body size, eye span, length in central anterior wing spot between D. fluegeli and of scutellar spine, wing length, length of IVS, OVS D. schulteni are described in quantitative terms. For and apical seta and also ratios between the various D. fluegeli it is described as “width of central ante- biometrical characters. However, in the taxonomy of rior wing spot broadening towards the wing edge (at Diopsidae this tool has, so far, not yet been used in a edge about 11% of wing length) and about equal to very systematic way. For linear measurements like eye its height”. For D schulteni is given: “width of central span or length of setae, collecting quantitative data anterior wing spot narrowing towards the wing edge, sets is relatively easy, but catching shapes like scu- width of this spot at wing edge about 5% of wing tum, surstylus or wing spots into quantitative sets is length and about half the height of the spot”. more difficult. Recently, Worthington et al. (2012) In order to examine how much variation occurs in discussed changes in head shape (eye, stalk, cen- the quantitative aspects of a wing spot in Diopsina, tral head) with increasing eye span in a sexually di- measurements were taken for the central anterior morphic species of stalk-eyed fly. Three-dimensional wing spot of D. kwaipai as a large series was avail- data sets would require an exact description of the able for this species. At the wing edge, the average ra- methodology used. Just as well it might be a useful, tio – central anterior wing spot/wing length (female though time-consuming, tool. In the genus Diopsis, and male taken together) – was 0.055 ± SE 0.001, for instance, the shape of the thorax is very useful at sd 0.006, n = 35, range 0.046–0.066. This clearly species-group level, but so far the shape has been in- indicates that the difference between D. fluegeli and dicated with expressions like ‘rounded’ or ‘relatively D. schulteni in the ratio for this spot (0.11 versus narrow’, in stead of, for instance, in a very basic 0.05) is more than sufficient to use it as a differen- quantitative way, a statistical description of the ratio tial character. In Fig. 55, the relation between various length/width. As can be seen in the various quanti- wing sections and wing length in D. kwaipai is pre- tative data discussed above, also in Diopsina quanti-

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Fig. 55. Diopsina kwaipai. Width of various wing sections – H-band, apical infuscation, central anterior spot and basal anterior spot (as indicated in Fig. 33) – plotted against wing length. tative characters can be very useful (see also Tables 1 placed in synonymy. For the Diopsina species this and 2). biometrical characterisation has now also been made The ratio eye span/body length is used in Diop- for the ratios eye span/body length for females and sidae studies to indicate the rate of sexual dimor- males combined (Fig. 56). The two species-groups phism – D – for this character in a quantitative and within Diopsina are clearly separate in the graph, graphic way (e.g. Baker & Wilkinson (2001), Fei- while D. intermedia again takes up its intermediate jen (2011) and Figs 5, 13, 34, 41 and 49 in this pa- position. per). The scatter diagrams can also be used for taxonomic purposes. Specimens represented by points Apical spurs on femora 2 and 3 clearly falling outside the normal distribution pattern For this minor character, Diopsina shows again a should be re-examined to see whether a mistake has remarkable variety. Diopsina kwaipai and D. africana been made in species identification (or even sex iden- have quite strong apical spurs on the femora 2 and 3, tification for that matter). Sets of graphs for species- D. intermedia and D. nitida have small apical spurs, groups or genera can also be used for their character- D. fluegeli sp. n. has tiny but distinct spurs, while isation. This type of allometric characterisation was D. schulteni and D. draconigena have no spurs. Feijen earlier discussed by, for instance, Kawano (2000) for (1978) mentions in the description of D. schulteni genera of stag beetles (Lucanidae) and Emlen et al. very small apical ‘spines’ on the femora 2 and 3, but (2007) for species of horned beetles (Scarabaeidae). these are really just the apical edges of the femora. Feijen (2011) indicated that this biometrical characterisation will be very useful to separate Te le op s is and Megalabops Frey, two genera which were earlier

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Fig. 56. Diopsina africana, D. draconigena, D. ﬂuegeli, D. intermedia, D. kwaipai, D. nitida and D. schulteni:eye span plotted against body length (females and males combined).

Vestiture on abdominal sterna species. In the Diopsinae genera Te le op s is , Cyrtodiop- The presence or absence of pollinosity (pruines- sis, Megalabops, Eosiopsis, Eurydiopsis Séguy & Van- cence) for abdominal sterna 1–5 forms a character schuytbroeck, nec Frey and most Diopsis only ster- that was somewhat neglected in the study of Diopsi- num 1 is glossy, while in just a few exceptions ster- dae, although it is mentioned in a number of species num 2 or even 2 and 3 are glossy. In six species of descriptions. In D. africana, D. kwaipai and D. inter- Diopsis,allEurydiopsis and almost all species of the media these abdominal sterna are mostly glossy (with Diasemopsis genus-group, a completely pollinose set some pollinose margins). In D. draconigena and D. of abdominal sterna occurs. The assumption can be nitida they are completely glossy, while in D. schul- that glossy sterna 1–5 form the plesiomorphous con- teni and D. ﬂuegeli sterna 1 + 2 + 3 are glossy and dition. In the Diopsinae this is usually reduced to, sterna 4 + 5 (thinly) pollinose. at most, only a glossy sternum 1. However, in the In Table 3, a summary is given of the state of Diopsinae, the genus Diopsina again forms the ex- this character in the various Diopsidae genera and ception with sterna 1–3 glossy in all species and 4–5 groups, while the condition in the sister family Sy- glossy in most species. ringogastridae is also indicated. In the Syringogastri- dae sternum 1 is glossy, sternum 2 variable (from Sclerotised ring glossy to (partly) pollinose), while sterna 3 and 4 The sclerotised ring (= genital ring, ventral sclerite, are pollinose, but in at least one species glossy (S. see Kotrba, 1995, 2000) of the ventral vagina wall Marshall, pers. comm. and own observation). In supports the evaginated part of the female postab- the more basal Diopsidae genera (Centrioncus, Te l- domen during copulation. It is usually only weakly oglabrus, Sphyracephala, Cladodiopsis), sterna 1 and sclerotised, so that it becomes rather weak and ﬂex- 2 are glossy, while sternum 3 is glossy in many + ible during preparation (maceration) of the geni- species and sterna 4 5 are glossy in some of the tal structures. As such, the shape can easily be dis-

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Table 3. Summary of the character state – presence or absence of pollinosity for abdominal sterna 1–5 – in genera and species-groups of Diopsidae. The condition in the sister-family Syringogastridae is also indicated.

(Sub)Family Genus Species/species-group Vestiture of abdominal sterna

Syringogastridae Syringogaster 1 glossy, 2 glossy or (partly) pollinose

Centrioncinae Centrioncus 1–2 glossy, in one 3–4 also glossy Teloglabrus 1–2 glossy, in one 3 also glossy

Sphyracephalinae Cladodiopsis 1–2 glossy, in some 3 or 3–5 also glossy Sphyracephala 1–2 partly or wholly glossy

Diopsinae Diasemopsis Almost all wholly pollinose, in a few 2 largely glossy genus-group Diopsina 1–3 glossy, in some 4–5 also glossy Eosiopsis 1 only anteriorly glossy Diopsis indica-group 1 glossy, in several Java species 1–3 glossy nigrasplendens 1 glossy, 2 mostly glossy most species 1 partly, mainly or wholly glossy longicornis, sulcifrons, servillei wholly pollinose & 3 other species Eurydiopsis wholly pollinose Eurydiopsis S&V nec F 1 glossy

Teleopsis genus-group Cyrtodiopsis 1 glossy Megalabops 1 glossy quinqueguttata-group 1 glossy, but in one species thinly pollinose Teleopsis most species 1 glossy selecta & sexguttata 1 only anteriorly glossy sykesii 1 thinly pollinose trichophora 1–2 glossy torted, so not much emphasis was given to this struc- Although the past twelve years saw considerable ture during earlier descriptions of Diopsidae. In most advances in the understanding of the phylogenetic Diopsidae (Sphyracephala, Diasemopsis, Diopsis, Cyr- relations of the Diopsidae genera, initially not much todiopsis, Te le op s is , Eurydiopsis), the sclerotised ring is emphasis was given to the position of Diopsina due rounded to ovoid to ellipsoid. Shape of anterior and to lack of fresh specimens. Meier & Hilger (2000) in posterior side can be somewhat different, while the their study on the egg morphology and phylogenetic shape might be tapering to one side. In the genus relationships of Diopsidae did not include Eosiop- Diopsis more variation in the shape appears to occur. sis, Cobiopsis Feijen 1989, Cladodiopsis and Diopsina. Feijen & Feijen (2012) describe for Diopsis stucken- However, they stressed that the position of the lat- bergi Feijen & Feijen and Diopsis eisentrauti Lind- ter two genera was thought to be of crucial impor- ner very broad lateral arms for the genital rings. In tance for understanding the relationships within the Diopsina the shape of the sclerotised ‘ring’ is charac- Diopsidae. They tentatively scored these two genera teristic for the genus: it is well sclerotised and almost for the adult characters in the data matrix and in- rectangular with very slender arms (Figs 9, 17, 37, 45 cluded them in the analysis. Baker et al. (2001) and and 54). Meier & Baker (2002) did not include Diopsina in their molecular and morphological studies. Kotrba Phylogenetic position of Diopsina (2004) placed Diopsina in a clade with the genera Various peculiar character states found in Diopsina Diopsis and Eurydiopsis Frey, albeit, as Kotrba et al. were indicated by Feijen (1989). These included (2010) commented “with very weak support”. Her basiliform prosternum, scutellum deeper than long, strict consensus tree showed Diopsina and Eurydiop- colour pattern of scutellar spines, presence (in some sis as embedded in Diopsis. species) of supra-alar, intra-alar, dorsocentral, acros- Kotrba et al. (2010) presented the ﬁrst molecular tichal and discal scutellar setae, strongly clavate ab- data for Diopsina, based on one nuclear and two mi- domen, small and equal-sized terga 1 & 2, large & tochondrial gene regions of a single fresh specimen broad terga 3 & 4, distinct seams in syntergum and of D. draconigena. Kotrba et al. stated that: “Both fused, slender, rod-like processus longi. Diopsina was maximum likelihood and Bayesian analyses recov- considered a genus that stands apart from the other ered a grouping of Diopsina/Diopsis/Eurydiopsis with genera through various autapomorphous conditions strong support (82% maximum likelihood boot- and (apparently) plesiomorphous characters states. strap percentage (mlBP) and 0.91 bayesian inference

Downloaded from Brill.com09/23/2021 11:40:06PM via free access 186 Tijdschrift voor Entomologie, volume 156, 2013 posterior probability (biPP)). The Diopsina/Diopsis/ which the latter two genera are sistergroups. Even Eurydiopsis grouping was also recovered in the maxi- if we assume this to be true, alternative hypothe- mum likelihood analyses for both individual genes, ses are feasible for some character states considered albeit with weak to moderate support (data not “reacquisitions”. For instance, the apical seta on the shown). Within this monophyletic clade, an alliance scutellar spines is clearly lost in Diopsis and most Eu- between Diopsina and Diopsis is shown to have mod- rydiopsis (recently the ﬁrst Eurydiopsis with an apical erate support (60% mlBP, 0.71 biPP)”. The group- bristle was discovered in Vietnam), but is present in ing by Kotrba et al. of Diopsina, Diopsis and Eu- Diopsina (and all other diopsid genera). This is then rydiopsis in one clade with especially the proposed for Diopsina apparently considered a reacquisition by sistergroup relation between Diopsina and Diopsis Kotrba et al. (2010). However, it appears more likely would have clear morphological and biogeographical that loss of the apical seta represents parallel devel- implications. opments in Eurydiopsis and Diopsis. The number of As far as the autapomorphic character states in character states that should be considered as reacquis- Diopsina are concerned, the following major states tions (basiliform prosternum, seams in syntergum-, stand: cephalic setae, thoracic setae, glossy sterna 1–3) can 1. scutellum deeper than long. also be considered remarkably high. 2. small and equal-sized terga 1 & 2, compared to So far, biogeographical implications of the var- large & broad terga 3 & 4. ious phylogenies presented have not been consid- 3. colour pattern of scutellar spines: pale base and ered. In the case of the two papers by Baker et al. tip, dark central section. (2001) and Meier & Baker (2002), the biogeograph- 4. fused, slender, rod-like processus longi. ical aspects do not present a major issue for the prin- 5. rectangular sclerotised ‘ring’ of the ventral vagina cipal clades. The Centrioncus genus-group (genera wall with well-sclerotised, slender arms. Centrioncus and Te log lab r u s )andtheDiasemopsis As far as apparently plesiomorphic character states in genus-group (encompassing the genera Diasemopsis, Diopsina are concerned, the following states should Chaetodiopsis, Trichodiopsis and Cobiopsis)areclades be considered: only occurring in the Ethiopian region. The Te le op - 1. basiliform prosternum. sis genus-group (genera Te le op s is , Cyrtodiopsis, Megal- 2. distinct seams in syntergum. abops,(?)Eosiopsis and the T. quinqueguttata species- 3. various thoracic setae, including scutellar apical group) is a clade purely Oriental in distribution. The seta and notal setae. basal Sphyracephalinae (genera Sphyracephala and 4. cephalic setae in addition to IVS and OVS. Cladodiopsis) form a clade with a much wider dis- 5. irrorated wings. tribution: Sphyracephala has a Holarctic, Ethiopian, 6. sexual homomorphy with regards to eye stalks. Oriental and Australasian distribution, while Clado- 7. investiture of abdominal sterna: glossy sterna 1, 2 diopsis is purely Madagascan in distribution. Only in and 3. the genus Sphyracephala a biogeographic complica- 8. smooth and rounded spermathecae. tion occurred as Baker et al (2001) indicated that the From their phylogenetic placement of Diopsina Ethiopian S. munroi and the Nearctic S. brevicornis “nested deeply within the Diopsini”, Kotrba et al. form together the sistergroup of the Ethiopian S. bec- (2010) concluded that this “sheds new light on the carii and the Oriental (from Malaysia) S. nr bipunc- evolution of various morphological characters within tipennis. Kotrba et al. (2010) included the Palaearctic the Diopsidae”. According to them, “the suture be- S. europaea in the munroi-brevicornis clade as sister tween the abdominal tergum 1 and 2 in Diopsina, species of S. munroi. once considered a possible plesiomorphy (Feijen This leaves the more complicated Diopsis/Eury- 1984, 1989), turns out to be a reacquisition as sug- diopsis/Diopsina clade (sensu Kotrba et al. 2010). If gested by Meier & Hilger (2000)”. The same they the phylogeny of this clade is superimposed on the considered true for the presence of “extra” bristles on actual geographic distribution of its three compo- the head and thorax and the presence of a basiliform nent genera, the biogeographic implications of the prosternum. In addition, Kotrba et al. stated that scenario are complicated. Diopsis forms a very large “the similarities of Diopsina with Te le op s is and Eu- genus of which eight of the nine subgroups, provi- rydiopsis, e.g., regarding the wing pattern, are more sionally distinguished by Feijen & Feijen (2009), oc- parsimoniously explained as synapomorphies subse- cur in the Ethiopian Region while only the Diopsis quently lost in Diopsis,thanasaresultofconver- indica-group occurs in the Oriental Region and a sin- gence. The statements by Kotrba et al. concerning gle species in Madagascar. Eurydiopsis is an Oriental apparent plesiomorphies which turn out to be reac- genus not even occurring in the western parts of the quisitions are based on their assumption that Eury- Oriental Region, but probably extending somewhat diopsis, Diopsina and Diopsis form a single clade in into the Australasian Region. Diopsina is a purely

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Fig. 57. Summarised Diopsidae phylogeny, based on Kotrba et al. (2010) but with biogeographic ranges now added. sub-Saharan genus. Based on the present knowledge molecular, morphological and biogeographical rea- of the Diopsidae phylogeny, we can assume that the sons, more evidence is required to confirm this plac- Diopsidae originated in Africa, certainly so if the ing. Work on molecular analyses of extensive series of Centrioncinae are included in the family. A biogeo- Diopsidae, including Diopsina species is, at present, graphical explanation of the phylogenetic tree (sum- in progress (F.A.A. Feijen, pers. comm.), but will still marised in Fig. 57, based on Kotrba et al. (2010) but take time to finalise. Early results of molecular analy- with the biogeographic ranges now added) could be ses of Diopsina africana and Diopsina nitida in com- as follows: bination with the Diopsina draconigena data from 1. Origin of Diopsidae in the Ethiopian region. Kotrba et al. (2010) confirm their placing in one 2. Branching-off Centrioncinae and stalk-eyed clade. Diopsidae in the Ethiopian Region. 3. Branching-off Sphyracephalinae and Diopsinae A few notes on the ecology of Diopsina in the Ethiopian Region. In Table 4, the available information on habitat 4. First migration of Diopsidae (Sphyracephalinae) and altitude where specimens were collected, is to Oriental, Palaearctic, Nearctic and Australasian summarised for the seven species. Most Diopsina Regions. If the initial Sphyracephala phylogeny species usually appear at altitudes of around or above based on five species is true, this migration would 1000 m. A clear exception is formed by D. fluegeli for entail at least two separate moves. However, spec- which the only known specimen was collected at sea ulation in this regard should await molecular level. The collecting places were usually near streams analyses of the remaining five described Sphyra- or swampy areas often near places with some shade. cephala and about 10 undescribed species. Diopsina species are not found in rain forests. For 5. Branching-off of the Diasemopsis clade from the D. kwaipai it was already known that they occur in other Diopsinae in the Ethiopian Region. clumps of bulrushes (Cyperaceae). By poking with a 6. Second migration of Diopsidae (Diopsinae, an- stick in these clumps, the flies start crawling upwards. cestors of Te le op s is genus-group) to the Oriental The habitat descriptions by M. von Tschirnhaus – region. see material studied for D. africana – now seem to 7. Third migration of Diopsinae (Diopsinae, ances- indicate that this closely related species also occurs in tors of Eurydiopsis clade) to the Oriental region. a habitat with Cyperaceae vegetation. The question 8. Branching-off Diopsina and Diopsis in Africa. is how close the relation between the species of the D. 9. Fourth migration of Diopsidae (Diopsinae, genus africana-group and Cyperaceae is. Most Diopsidae Diopsis,ancestorsofD. indica-group) to Oriental are saprophagous in the larval stage, but a number of Region. Recent molecular analysis of a Diopsis Diopsis species are primary or secondary stem-borers nr indica places it close to African Diopsis with in Poaceae. Whether the relation of the species of the apical wing spots (F.A.A. Feijen pers. comm.), so D. africana-group with Cyperaceae is phytophagous the option of a polyphyletic Diopsis as far as its or saprophagous, remains to be investigated. It ap- Asian and African species is concerned, can be pears anyway unlikely that the clumps of bulrushes discarded. just form a non-food hiding place. This scenario appears rather complicated, but might Shillito (1940) stated that in life his D. africana be possible. “has a strong resemblance to an ant, the eye-stalks At present, the Diopsina/Diopsis/Eurydiopsis giving the illusion of strong antennae and the wings grouping is the only theory available which con- held flat over the abdomen serve to exaggerate the siders the place of Diopsina within its family. For

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Table 4. Summarised data on habitat and altitude for the Diopsina species.

Diopsina Altitude (in metres) Habitat Holotype Range africana-group africana 1500 400–1630 Near streams, swampy areas with bulrushes intermedia 1400 800–1400 – kwaipai 875 – Clumps of bulrushes in flood plain near small river nitida-group draconigena 1800 1000–1800 Tufts of grass near streams in Drakensberg and surrounding areas fluegeli sp. n. 7 – Floodplain near river nitida 1500 560–1600 Shady riversides, swamps and humid savannah schulteni 380 380–2100 Near rivers petiolation”. Shillito certainly had a point in indi- nomenclatural issue with the subfamily name Dy- cating the resemblance to ants, but his supporting opsina/Diopsina (Lepidoptera). Kees van Achterberg remarks about eye-stalks looking like antennae and (RMNH) advised in the use of the motorised stere- wings emphasizing petiolation are not very strong. omicroscope and AnalySIS Extended Focal Imaging Feijen (1981) indicated that “in general all species of Software. The two anonymous referees provided very Diopsina are ‘crawlers’ rather than ‘fliers”’. He also re- useful comments. marked that the often brachypterous D. draconigena might have taken this way of life a step further. References Diopsidae are frequently parasitised by Laboul- Adams, C.F., 1903. Dipterological contributions. – Kansas beniales. However, Feijen (1984) remarked that in University Science Bulletin 2(2): 21–47. Diopsina Laboulbeniales are quite rare. He found Aurivillius, P.O.C.,1886. XIV. Lepidoptera. – In: P.Mayer only a single D. africana infected with a cluster & W. Giesbrecht (eds), Zoologischer Jahresbericht für of about 20 Stigmatomyces sp. mesally in between 1885. Herausgegeben von der Zoologischen Station terga 3 and 4. This fungus was subsequently de- zu Neapel II. Abtheilung: Arthropoda: 442–541. R. scribed as Stigmatomyces feijenii by Rossi (1990). In Friedlander & Sohn, Berlin. the Diopsina now studied, additional infestations by Baker, R.H., G.S. Wilkinson & R. DeSalle, 2001. Phyloge- Laboulbeniales were found. Of the two females and netic utility of different types of molecular data used to six males of D. africana collected by M. von Tschirn- infer evolutionary relationships among stalk-eyed flies haus in 2012 in Uganda one female and two males (Diopsidae). – Systematic Biology 50: 87–105. were infected by a species of Rhizomyces Thaxter. In Baker, R.H. & G.S. Wilkinson, 2001. Phylogenetic anal- total they contained 14 of these fungi on the ven- ysis of sexual dimorphism and eye stalk allometry in tral abdomen, of which 13 on the right-hand side. stalk-eyed flies (Diopsidae). – Evolution 55(7): 1373– 1385. Of the three females and five males of D. nitida col- Billberg, G.J., 1820. Enumeratio insectorum in Museo lected by M. von Tschirnhaus & F. Menzel in 2012 Gust. Joh. Billberg. – Gadelianis, Stockholm. 138 pp. in Uganda two males were infected by a Rhizomyces Bruggen, A.C. van, 1961. Chapter VIII. Diptera (Brachyc- sp.: one with 15 specimens on the ventral thorax, era): Diopsidae. A partial revision of the Diopsidae or mainly on the coxae, and the other with one spec- stalk-eyed flies of Southern Africa. – In: B.P.Hanstrom, imen between coxae 2 and 3. P. Brink & G. Rudebeck (eds), South African Ani- mal Life, Results of the Lund University Expedition in 1950–1951, Vol. 8: 415–439. Almqvist & Wiksells Acknowledgements boktryckeri AB, Uppsala. Hans-Joachim Flügel provided the type specimen Cogan, B.H. & J.F. Shillito, 1980. 47. Family Diopsidae. for D. fluegeli. Gerard Schulten donated additional – In: R.W. Crosskey (ed.), Catalogue of the Diptera specimens of D. schulteni.MarionKotrbaprovided of the Afrotropical Region: 583–587. British Museum loan of specimens and determined the sex of some (Natural History), London. ZSM Diopsina. Michael von Tschirnhaus and Frank Cumming, J.M. & D.M. Wood, 2009. Adult morphol- Menzel made their collections of D. africana and D. ogy and terminology. – In: B.V. Brown, A. Borkent, nitida from Uganda and Togo available for study. J.M. Cumming, D.M. Wood, N.E. Woodley & M.A. These latter flies were especially useful for molec- Zumbado (eds), Manual of Central American Diptera, ular analyses. Steve Marshall examined some Sy- Vol. 1: 9–50. NRC Research Press, Ottawa. Curran, C.H., 1928a. New Stratiomyidae and Diopsidae ringogastridae for the vestiture on abdominal sterna. from the Belgian Congo (Diptera). – American Mu- Rienk de Jong was helpful in sorting out the seum Novitates 324: 1–5.

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