A Contribution to the Taxonomy of Tanytarsini (Diptera: Chironomidae) of Sub-Saharan Africa, with a Description of a new Genus (Afrozavrelia) and five New Species from other Genera

14 Pages·2002·9.3 MB·English

by  A D Harrison

)
A CONTRIBUTION TO THE TAXONOMY OF TANYTARSINI (DIPTERA:
CHIRONOMIDAE) OF SUB-SAHARAN AFRICA, WITH A DESCRIPTION OF A NEW
GENUS (AFROZAVRELIA) AND FIVE NEW SPECIES FROM OTHER GENERA
A D Harrison
I'rcshwcUcrResearch Unil. DeparliiieiuofZoology,
UniversitytfCapeTown. SindhAjririi
E-inail:[email protected]
ABSTRACT
A briefoverview is given of existing knowledge of the systematics of Tanytarsini in sub-Saharan Africa. A new
genus, Afrozcivrelia, is established for Zavrelia kribiensis Kieffer and five new species (Rheotanytarsiis shebelensis,
Tanytarsiis awashensis, Tcmytarsiis fhimiiieiis, Taiiytarsiis zimbabwensis and Virgatanytarsns aboensis) are also de-
scribed. An additional note, on the diagnostic features ofthe larvae and pupae oftwo other species (Rheotanytarsiisfiisciis
Freemanand RheotanytarsiisiiioiitaniisLehmann) and the pupa ofRheotanytarsiisguineensis Kieffer, is also provided.
Key words; Chironomidae,Tanytarsini,Ethiopia,Zimbabwe, South Africa, newgenus, newspecies,Diptera, systematics.
INTRODUCTION
Cladotanytarsiis: 10 species. One species (C. cre-
There are a number of reliable publications on bus) described by Lehmann (1981); six species de-
the systematics of the tribe Tanytarsini (Diptera, scribed by Ereeman & Cranston (1980); three spe-
Chironomidae) in Africa south ofthe Sahara: Free- cies-C. irsaciis, "Tanytarsiis’biikcmts and "Tanytarsiis’
man 1958) described new species and revised the congolensis - described by Lehmann (1979). {Note:
(
work of earlier taxonomists, Kieffer and Goetghe- Ekrem (1999) transferred T. bukaviis and T. congo-
buer. Kyerematen & Stether (2000) reviewed the lensis to Cladotanytarsiis.
Afrotropical Rheotanytarsiis, and Ekrem (2001) Nidmirbia: one species, N. capicola, described by
reviewed the Afrotropical Tanytarsiis. All these au- Siiwedal (1982). This was originally placed in
thors included useful keys in their publications. Micropsectra by Ereeman (1958).
This does not exclude the likelihood that there Stenipellina. Two species; S. chanibiensis Goetghe-
are not more Tanytarsini to be described from the buer in Ereeman (1958); S. reissi described by Leh-
region, especially those of the mountain chain that mann (1981).
extends from South Africa to Ethiopia in the north Stenipellinella: one species. Although Freeman (1958)
(see Ekrem 2001). This paper describes five new described "S. triincata’ as a species of Stenipellina,
species from this mountain chain or its foothills this species fits more closely into the genus Steni-
and also sets up a new genus, Afrozavrelia, for pellinella Brundin as it has a number of features
Zavrelia kribiensis Kieffer, a species that does not fit more characteristic of the latter genus: in the adult
into the genus Zavrelia Kieffer in any life stage. male the anal point has longitudinal crests extend-
The descriptions of taxa in this paper are based ing onto the anal tergite with basal spinules be-
on studies of museum collections, from specimens tween; the pupa has a shagreen pattern similar to
collected from Ethiopia, Zimbabwe, and South Af- that of Stenipellinella brevis (Edwards) (Finder &
rica (see ‘Methods’ for further details). Reiss 1986) and segment VIII has a single, robust
sclerotized postlateral spine; the larval antenna is,
THETANYTARSINIINSUB-SAHARANAFRICA however, of the Constenipellina-type with both
The 64 sub-Saharan Tanytarsini previously de- Lauterborn organs being distal on segment 3 and a
scribed by various authors can divided into two pedestal with a prominent apical spur. (This de-
categories: 62 species in recognized or newly- scription based on pupa, a pharate male and larval
described genera, and two species that cannot be head capsule from the same sand grain case, Cat.
placed in known genera. These are discussed be- ABLER 9J, in AM).
low, together with references to source publications Friederia villosa Stether & Andersen (Stether &
and short notes on the diagnostic features ofsome spe- Andersen 1998).
cies. Virgatanytarsns - three species; V. arduennensis
Species in recogniz.edornewly-describedgenera (Goetghebeur) (= subreflexens Ereeman), V. nigri-
Tanytarsiis: 26 species (Ekrem 2001). cornis (Goetghebeur) (see Freeman 1958) and
V. aboensis, described in this paper.
Rheotanytarsiis: 19 species (Kyerematen & Stether Zavrelia kribiensis Kieffer {=Afrozavrelia sp.): one
2000
).
AnnalsoftheEastern CapeMusewnsVol. 3(February2004): 1-15
.
.
species. In this paper this species is placed in a Abbreviations
new genus, Afrozavrelia. AR
antennal ratio. Ratio of length of apical flag-
Species thatcannotbeplaced in known genera ellomeretocombined length of basal flagel-
lomeres.
‘‘Tanytarsus’ abnormis' (Lehrmann, 1981) LR
leg ratio. Ratio oflength of tarsomere 1 tolen-
Characteristic features: hairy eyes with no dorsal
gth oftibia.
extension, superior volsella with digitus but no SV ‘Schenkel-Schiene Verhaltnis’: Ratio of femur
median volsella.
plus tibia to tarsomere
1
‘Tanytarsus’ saetosus (Lehrmann, 198!) BV ‘Beinverhaltnisse’. Combined length of femur,
Characteristic features: hairy eyes with no dorsal tibia and tarsomere 1 divided by length oftar-
extension; costa ending well proximal to M3+4; someres 2 to 5.
ADH A D
anal point bare with a small knob-shaped ‘point’, Harrison (Collector).
but superior volsella and median volsella of Tany-
TAXONOMIC DESCRIPTIONS
tarsiis-type.
METHODS Afrozavrelia gen. nov.
Ethiopian specimens were collected by the au- Generic diagnosis
thor while working in the cooperative progiamme ADULT MALE
described in the Acknowledgements. The Zimbab- Size: small, wing length about 1 mm.
wean material was collected by the author working Head: antenna with 10 flagellomeres; no frontal tu-
in the Zoology Department, University of Zim- bercles; eyes hairy with long dorso-medial exten-
babwe (then Rhodesia) financed by the Rockefeller sions; palps normal, segment 3 with no subapical
Foundation of New York. Specimens from the
sensilla.
Western Cape Province were collected by the author Thorax: with antepronotal lobes widely separated
or by members ofthe Freshwater Research Unit, Zo- overreaching pronotum, no tubercle; acrostichals
ology Department, University ofCape Town; the rest
22, biserial, dorsocentrals 18, partly biserial, prealars
oC.f tdheeMSooourthanAdfrhiicsantemaamteartiathlewAalsbacnoyllMecutsedeubmy,DGrraF-. c2,lotshuepdraw-iatlhars1e,tase,cutceolsltaarsnoutnipsreroidaulc.edW,inRg4s+5 deenndsienlgy
hamstown. Eastern Cape. before tip of M3+4, Anal lobe not developed,
Pinned specimens were treated as follows: the squama bare.
wings were removed from the dried specimen and
Legs: fore tibia with short, straight spur, other tibia
mounted directly in Canada balsam, then the rest with small combs well separated each with a thin
of the specimen was macerated in 5% potassium spur. Pulvilli absent.
hydroxide at room temperature for 24 hours; the Hypopygium: anal tergite bands weak not meeting
KOH was removed by placing it in 70% alcohol centrally, about 12 anal tergite setae, anal point
for about 10 minutes, and then into 96% alcohol. It long, bare with rounded tip, superior volsella long
was then dissected and mounted in Canada bal- with broad digitus, median volsella with few lamel-
sam-dissolved in cellosolve-on the same slide as liform setae and no simple setae, inferior volsella
the wings. Specimens preserved in alcohol were long extending up to, or beyond tip of gonostylus
dissected and mounted in the same type of balsam. which is narrow with two long setae at tip.
Drawings were made by means of a drawing tube
on a compound microscope. Measurements were ADULT FEMALE
made with an eyepiece micrometer in the com- (based on one pharate specimen)
pound microscope. Morphological terminology is Size: similarto male.
according to Saether (1980) and the description of Head: general structure similar to male; antenna
the males follows the style of Ciunston, Dillon, with five flagellomeres.
Pinder& Reiss(1989),usingtheirgeneric definitions. Thorax: similar to male. Wings and legs appear to
The descriptions of females follows the style of be similar to male.
Saether (1977). Genitalia: sternite VIII not forming a distinct floor
The holotypes and paratypes of all the species under the anterior part of the vagina; gonocoxapo-
described here and other material used in the de- demes narrow and joined, gonopophysis of VIII
scriptions have been deposited in the Zoologische simple, gonocoxite IX small with two setae, coxos-
Staatssammlung, Munich, Germany (ZSM) or in ternapodemes very small andcurved; segment X with-
the Albany Museum, Grahamstown, 6140, Eastern out setae, postgenital plate pointed, cerci small; semi-
Cape Province, South Africa (AM). The catalogue nal capsules oval with short necks, ducts convoluted
numbers ofthe specimens are given in the text. joiningto acentral bulb with common opening.
Harrison: TanytarsiniofSub-SaharanAfrica
PUPA consisting of three separate, slender distally pointed
Size: small, in straight cases composed mainly of scales; premandible with two teeth and well-
diatom frustiiles and detritus. formed brush; mandible with dorsal tooth with
Cephalothorcvc cephalic tubercles low and rounded, three inner teeth, seta sub-dentalis long and
frontal setae flat, almost taeniate, no antepronotals or curved, seta interna small and plumose, pecten
dorsocentrals, thoracic horn long, pointed and mandibularis consisting of about 10 long lamellae.
down-turned, no spinules, minutely rugulose, three Mentum with median tooth rounded, six lateral
precorneal setae small, short and flattened. teeth, the second being shorter then the first and
Abdomen: tergites I and II bare, II with a short hook third; ventromental plates fan-shaped, widely sepa-
m
row, to VI with paired, elongate patches ofpoints, rated.
simple S setae on segments II to IV, taeniate S setae Body: anterior and posterior parapods with simple
on V to VIII; segment VIII with a few small spines at hooks, procercus with long anal and lateral setae.
posterolateral comer; anal lobes with moderately de- NOTES
velopedfringe oftaeniate setae; no pedes spurii.
Afrozavrelia can be distinguished from Neo-
LARVA zavrelia and Zavrelia in all life stages (Table 1). In
Size: small, in straight, portable cases consisting some particulars - such as the anal point struc-
mainly ofdiatom frustules and detritus. ture, the presence of a digitus, and the terminal
Head: with five-segmented antennae, of about Lauterborn organs - the former genus resembles
86% ofhead capsule length, on prominent pedestal, Neozavrelia. In other particulars - such as the
AR about 0.6, long basal segment with ring organ hairy eyes, the antennal tergite bands not meeting,
near base and seta subterminally, blade shorter that and the more complete anal fringe of the pupa - it
segment 2, accessory blade present, Lauterborn or- resembles Zavrelia. Nevertheless, in many other
gans large, terminal on segment 2, sessile, style particulars-such as the strongdorsal extension ofthe
present. Labrum with SI palmate, bases fused, SII eye, the very naiTOw gonostylus, the lack of a floor
plumose on tall pedestal. Sill and IV seta-like, to the anterior vagina, the taeniate frontal setae of
labral lamella well-developed, pecten epipharyngis the pupa, the long antennae ofthe larva (especially
Table 1: Morphology ofAfrozavrelia contrasted with that ofNeozavrelia and Zavrelia
Afrozavrelia Neozavrelia Goetghebuer Zavrelia Kieffer
Eyes hairy with longdorso-medial exten- Eyes bareorwith shortpubescence, no Eyeshairy, nodorsomedial extension
sion dorsomedial extension
Fronttubercles absent Fronttubercles absent Small frontal tubercles
Anal tergite bands weak, not meeting Anal tergite bands fused, forming Anal tergite bands not meeting
w V-shape
-<J
Anal point bare dorsally Anal pointbaredorsally Anal point with crests and spinules
Digitus present Digitus present Nodigitus
Median volsellawith very few larnelliform Median volsellawith numerous setae, Median volsellawith numerous se-
setae some slender tae, some simple
Gonostylus very narrow Gonostylusbroad Gonostylus broad
No floorunderanteriorvagina Floorunderanteriorvagina(Cranston Floorunderanteriorvagina
1998)
FEMALE
Frontal setaetaeniate Frontal setae normal Frontal setae normal
Thoracichorn without spinesorapical Thoracichorn withoutspines, with or Thoracic horn with spines
< teeth withoutapical teeth
(DX
CL Posteriolateral comb weak, ofafew small Posterolateral comb strong,ofnumerous Posterolateral comb with singleor
light teeth dark teeth doubledark teeth
Anal lobe with fringeofabout22 taeniae Anal lobe fringe of5-14 taeniae, orre- Anal lobe with fringeof 17-20
duced taeniae
< Antennalong, 86% length ofheadcapsule, Antennashort, basal segment about as Antennashort, basal segment about
> basal segmentlongerthan flagellum long as flagellum as long as the flagellum
<
-J Lauterbornorgansterminalatidsessile Lauterbornorgans terminal and on pedi- One Lauterbornorgan sub-terminal,
cels both on pedicels
AnnalsofilieEasternCapeMuseumsVol. 3(February2004): 1-15 . 3
the basal segment), and the short antennal blade ADULT FEMALE
It resembles neither ofthe above two genera. (based on a pharate specimen, mounted).
& mm
Saether Andersen ( 1998) describe another Body: length 1.6
African member of the subtribe Zavreliina (that Head: general structures as male, antenna with five
was erected by Saether (1977)): Friederia villosa flagellomeres.
Saether & Anderson, from Ghana. The genus Thorax. Setation: acrostichals 22 biserial, dorsocen-
Friederia differs very markedly from Afrozavrelia, trals 14, posteriorprealars 2, supra-alar 1, scutellars 5
however, as it has bare eyes, an anal point with per side. Wings and legs appear to be similar to
setal tufts, superior volsella with no digitus, and those ofthe male.
median volsella reduced to a small tubercle with Genitalia (Eigs 5 & 6): sternite VIII not forming a
one, simple seta. The female and immatures are distinct floor under the anterior part of the vagina,
unknown. gonocoxapodemes narrow, light, joined; gonopophy-
sis simple but with ventrolateral enlargement; gono-
Type species
coxite IX small with two setae; coxosternapodemes
Zavrelia kribiensis Kieffer. very small, light, curved; segment X without setae;
postgenital plate pointed; cerci small, 27 pm; semi-
Afrozavrelia kribiensis (Kieffer)
nal capsules (Fig. 6 oval with short necks, 42 pm
(Figs 1-13) )
long, with neck; ducts convoluted joining to a cen-
Zavrelia kribiensis Kieffer, 1923 tral bulb and with acommon opening.
& Also described in Freeman (1958) and Freeman PUPA (N = 5 mounted)
Cranston (1980).
Remain in larval cases, made mainly of diatom
The description ofthe male, given above (in the
frustules and detritus.
generic diagnosis) and below, is more detailed than
Exuviae: almost colourless, transparent.
that of Freeman (1958) and the female, pupa and
Cephalothorax: cephalic tubercle low and rounded,
larva are also described. The female and imma-
frontal setae flat, almost taeniate; dorsum minutely
tures were associated from pupal cases with
pebbled; no antepronotals or dorsocentral setae;
pharate males and females.
thoracic horn (Fig. 7) long, pointed and down-
ADULT MALE (N == 4 mounted) turned, no spinules, minutely njgulose; precorneal
Body: length 1.1 mm. setae small, short and flattened; wing sheath with
Wing: length 0.9 mm; body colour very light nose.
brown, halteres dark tipped. Abdomen (Fig. 8): tergites I and II bare, II with
Head (Fig. 1); No frontal tubercles; antenna AR short hook row of small rounded “hooks”; tergites
0 6 10 flagellomeres, eyes hairy with long dor- III-VI with paired elongate patches ofpoints; S setae
. ,
somedial extensions. Head setation: six inner verti- (simple)- I none, II one. III and IV three; S setae
cals, two outer verticals, 30 clypeals. Length of palp (taeniate)-V, VI, VII four, VIII five; segment VIII
segments, 15, 21, 24, 60, 111 pm; no subapical sensil- with a few small spines at posterolateral corner
laeon segment 3. (Fig. 8); no pedes spurii. Anal lobes moderately
Thorax. Setation: lateral antepronotals nil, acros- well developed with a complete fringe of about 22
tichals 22 biserial, dorsocentrals 18 biserial anteriorly, taeniate setae per side.
posteriorprealars 2, supra-alar 1, scutellars4 perside. LARVA
Wings (Fig. 2): broad, anal lobe not developed; (N = complete specimen, mounted; also based
densely clothed in setae; squama bare; R4+5ending on five la1rval exuviae in pupal cases.)
before tip ofM3+4, costa not extended. The larva lives in a straight, portable case made
Legs: fore tibia with short, straight spur, other tibia mainly ofdiatom fnjstules and detritus.
with small combs, well separated each with a thin Colour: yellowish.
spur; LR fore 1.5, mid 0.6, hind 0.7; SV fore 1.7, BV Head: capsule 168 pm long, dorsal surface smooth.
fore2.5. Antenna (Fig. 9) 144 pm long, with five segments
Hypopyginm (Figs 3 & 4): anal tergite bands weak on pedestal 84 pm high with a prominent apical
and not meeting, about 12 anal tergite setae, anal spur. AR 0.6. Long basal segment with ring organ
point long, bare with rounded tip, superior volsella near base and seta subtenninally, blade shorter than
long with broad digitus, median volsella (Fig. 4) segment 2 accessory blade half the length of blade,
with one, or possibly two, lamelliform setae, no both Laute, rbom organs terminal, sessile almost as
simple setae, inferior volsella longer than the com- long as segment 3, stylepresent, segment fivefineand
bined length of the gonocoxite and gonostylus;
pointed.
gonostylus narrow with two long setae at the tip. Labrum (Fig. 10): SI palmate, bases fused, SII
4 Harrison:TanylarsiniofSub-SaharanAfrica
plumose situated on tall pedestal, Sill and SIV tooth rounded, six lateral teeth, second tooth
seta-like; labral lamella well-developed; pecten epi- shorter than the first tooth, then regularly decreas-
pharyngis consisting of three separate, slender, dis- ing in size; ventromental plates fan-shaped with
tally-pointed scales. Premandible (Fig. 1 1) with two anterior margin smooth and widely separated.
teeth and we11-formed brush. Body, anterior and posterior parapods with simple
Mandible (Fig. 12): dorsal tooth light yellow, api- hooks; procercus broader than long with long anal
cal tooth and two inner teeth light brown; seta sub- and lateral setae.
dentalis long and curved, not extending beyond the
SPECIMENS EXAMINED
apex; seta interna small and plumose; pecten man-
All from Western Cape Province, South Africa,
dibularis consisting ofabout 10 long lamellae.
Mentum (Fig. 13); all teeth light brown, median 6', Molenaars River, 33'’43'S 19“l0'E, 27 iv 96
Figs 1-13. Afrozavrelia kribiemis. 1-4, adult male; !, head; 2, wing; 3, hypopygium; 4, median volsclla. 5-6, adult Icmale: .3, geni-
talia; 6, seminal capsules and ducts. 7-8, pupa: 7, thoracic horn and frontal setae; 8, abdominal tergites II-IV. 9-13, larva:
9, antenna: 10. labium; 1 1, premandible; 12, mandible; 13, mentum.
AnnalsoftheEastern CapeMnseninsVol. 3(February2004): 1-15 5
.
(cat. SAC.45R) (collector ADH) also 3 SS, Eer- Legs: foretibia with short spur on scale; all combs
ste River, 33°56’S 19°10'E (Cat. E1Q2 24R, S2Q2 with spurs. Leg measurements and ratios are given
7M, S2Q2 lOR) (collector Denise Schael, 1998); in Table 2.
with 1 $ (Cat. RTDU.219), 2 pupae (Cat. RTDU. Hypopygium (Figs 14, 15, 16, 17): anal tergite bands
282 with pharate (S and 148H with pharate $, transverse or slightly V-shaped, not meeting; anal
cases contained larval remains, used for associa- point without spine patches and downturned; supe-
tion), 3 larvae (Cat. RTDU, 294, 282 and 148H) rior volsella club-shaped without microtrichia (Fig-
(collector Rebecca Tharme, 1993-95). All material 14); median volsella (Fig. 16) with distal filamen-
in AM. tous setae long extending beyond apex of inferior
volsella, almost reaching the tip of the gonostylus,
NOTES
without median bend; distal setae narrow with no
Habitat Preferences: The South African speci- plate-like structure; inferior volsella normal, gonosty-
mens were found in montane rivers with soft, un- lus tapering gradually. Figure 14 illustrates the Eth-
buffered water. The larvae live in straight portable iopian specimen (the holotype) and Figs 15 & 16 a
cases ofdiatoms and detritus and they appear to be South African specimen with a narrower anal point
detritivores or scrapers. and a somewhat smaller superior volsella. Some
Distribution: Cameroon, Kribi; South Africa, West- South African specimens have superior volsellae of
ern Cape Province. intermediate size. Fig 17 illustrates the apodemes
ofthe type.
Rheotanytarsus shebelensis sp. nov.
SPECIMENS EXAMINED
(Figs 14-17)
ADULT MALE (N = 3 mounted) Ethi1(o5p'iafnouHingdhladnrdosw,ne0d7,°01W’aNb3e9"0S3h'eEbel(eETC(r.i3v4erF)),
Close to the generic definition in Cranston et 1984.1.4, collector ADH (ZSM); 2 SS from light
al. (1989) except for the structure of the medium trap. Little Mooi River, KwaZulu-Natal, 29*^13'S
volsella that has no plate. 29^53E, (MOI 56CD & CH) and 2 SS from light
Body length: 1.92 mm.
trap, Kleinmooi River. KwaZulu-Natal. 29'^13'S
Wing length: 1.3 mm. 29^53E, 4.iv. 1995 (Cat. MOI. 65BT & CB), col-
Colour: Head and antennae brown; thorax and legs lectors F. C. de Moor and team (all in AM).
brown, vittae, preepisternum and postnotum dark Holotype ETC. 34F; paratype S MOI 65BT.
brown; abdomen brown with noobvious markings.
Head: AR 0.43-0.47; palp segments: 24-30, 27-30, NOTES
60-63, 78-81, 144-150 /tin; no subapical sensillae on This species falls into the Rheotanytarsiis pel-
palp segment 3. Head setation: temporals 7, clypeals liicidiis group of Kyerematen et al. (2000) but it
15. can be taken no further than couplet 3 of their key
Thorax: no scutal tubercle; setation: lateral ante- as it has filamentous not foliate setae on the median
pronotals nil, dorsocentrals 9, posterior prealars 1, volsella. Ifthis is neglected it would key out at cou-
scutellars 4 per side. plet 5. It can be distinguished from the two species
Wings: most of the surface covered with setae. keyed there as follows: from Rheotanytarsiispellu-
R2+3 absent. Setation of veins: R 22, R| 26-29, cidiis (Walker) by not having the anal tergite bands
R4+5 50, seta also on other veins. clearly V-shaped, with the median volsella without
Table 2. Rheotanytarsiis shebelensis leg measurements in pm and ratios
fe tl ta. ta2 ta3 tar ta. LR BV SV
Pi 528 288 588 324 240 168 98 2.0 1.7 1.4
P2 540 420 204 132 84 72 48 0.5 2.9 4.7
P3 600 504 300 204 168 120 72 0.6 2.5 3.7
Legend: fe = femur; ti= tibia; ta,. ta^, ta,, taj tas= tarsomeres 1-5; LR = legratio (length of tarsomere I: length oftibia); BV =
'Beinverhaltnisse’=combinedlengthoffemur,tibiaandtarsomere 1 dividedbylength oftarsomeres2to5;SV=‘Schenkel-SchieneVerhalt-
nis’=ratiooffemurplustibiatotarsomere 1
6 Harrison: TanytarsiniofSub-SaharanAfrica
Figs 14-17. Rheolanylarsiisshcbelcnsis, adult male: 14, hypopygium (Ethiopian); 15, liypopygium (South African); 16, median vol-
sclla; 17, apodemes.
a median bend and lacking microtrichia on the su- ing small points. One long precorneal seta extends
perior volsella. It can be distinguished from Rheo- as far as the bend ofthe cephalic horn as shown in
tanytarsus huculicaudus Kyerematen & Stether by Fig. 18 (one ofthe mounted specimens), the other
not having the anal tergite bands fused and with two being very short. Figure 19 shows details of
the gonostylus not abruptly but gradually narrowed the pupal anal spur on VIII. Otherwise these
(rather like that of R. pellucidus). In the key in specimens conform to the descriptions of Kyere-
Kyerematen and Saether (2000) it keys to R. hucii- maten & Saether (2000) and Scott ( 1967).
licaiuliis but differs from it as above.
LARVA
Etymology: shehelensis referring to the Wabe She-
(Numerous mounted and unmounted specimens).
bele (river) Ethiopian Highlands.
Habitat preferences', the larva has not yet been Body length: 2-4 mm, depending on trophic con-
identified but it is assumed that, like most other ditions.
members of the genus, it lives in the current in Colour: Scott notes; “In life the head is bright red-
cases constructed for filter feeding. The adults dish brown and the abdomen greenish. In alcohol
were all collected drowned in or near rivers. the head is brown and the abdomen yellowish
Distribution: Ethiopian Highlands and KwaZulu- white.”
Natal, South Africa. Antenna: as per Scott, Lauterborn organs reach
base ofsegment 5.
Rheotanytarsiisfiiscus Freeman Labruni: similar to R. curtistylus Goetghebuer.
&
(Eigs 8-20). Illustrated by Pinder Reiss (1983).
1
Tanytarsns (Rheotanytarsiis)fuseus Ereeman 1954 Mandible: as per Scott (1967), all teeth are dark.
Mentuni: all teeth are dark, width of ventromental
& Also described in Ereeman ( 1958) and Ereeman plate 0.95 x width ofmenturn.
Cranston 1980).
195T8)heanaddutlht(emaadluletimsadleescarnidbepdubpya FbyreKeymearnem(a19t5e4n && Mdaexviellolpaed(,Figt.her2e0);is tnhoe pleaccitneanl gcahlaeeatraise aanred wtehlelr-e
are two setae maxillaris.
Saether(2000) but the pupal specimen irsed by the lat-
Body: Scott (1967) illustrated the posterolateral
ter authors lacked the thoracic honi. Scott (1967) bifid setae on segments III to VI. One branch lies
described the distinctive characteristics ofthe pupa
anteriorly, the other posteriorly, both are plumose
and larva and also gave a detailed account of the
and are about as long as one third of the segment.
biology and behaviour of this species. Certain fea-
These are best .seen on unmounted specimens as
tures of the pupa and larva have not yet been de-
the mounting medium may make them transparent
scribed and are added here.
and difficult to see. The anal setae are long and
PUPA (N = 2 mounted) dark brown and the anal papillae are short with
rounded tips.
Scott (1967) illustrated the cephalothorax from
the lateral and dorsal view; showing no frontal se- SPECIMENS EXAMINED
tae and none could be detected on the specimens pupa; Cecilia Ravine, Table Mountain,
1
examined here. In lateral view the cephalic horn is 33°60'S I8“25'E, i.98 (cat. ABLCR.7T), collector
shown to be of the usual Rheotanytarsiis type with Deni.se Schael; larvae from small waterfall.
a broad base and a down-turned distal section bear-
AnnalsoftheEastern CapeMuseumsVol.3(February2004): l-LS .
Silvermine River, 34"05'S 18°25'E (cat. SAC. SPECIMENS EXAMINED
37K) 24 ix 95, collector ADH (all in AM). Two mounted pupae and one larva from the con-
NOTES fluence of the Mpisini and Manzamnyama Rivers
near Lake Mzingazi, 32“09'S 28°42'E(Cat. MpMan.
Habitatpreference: stony torrents.
8/96 (1)) viii 96, collectorPetra Vos, (all in AM).
Distribution: in permanent mountain streams in
southern Africa. NOTES
Habitat preference: running water; tolerates slower
Rheotanytarsus guineensis Kieffer flow than some other species ofthe genus.
(Figs 21-25) Distribution: tropical and sub-tropical Africa.
Rheotanytarsusguineensis Kieffer, 1918
Tanytarsus(Rheotanytarsus)guineensisFreeman, 1958 Rheotanytarsus montanus Lehmann
Also described in Freeman & Cranston (1980) and (Figs 26-33)
Kyerematen&Ssether (2000). Rheotanytarsus montanus Lehmann, 1979
The male hypopygium is described by Freeman Also described in Kyerematen & Saether(2000).
(1958) and the hypopygium, female genitalia and Lehmann (1979) described the adult male and
pupa are described by Kyerematen & Saether (2000). the pupa; Kyerematen & Stether (2000) described
More details of the pupa and a description of the the adult male. The adults are dark brown to almost
larva are given here. One larva was taken from a black flies, apparently more heavily chitinized and
pupal case with pupa containing pharate male. more compact than other African members of the
genus. The species is found in upper mountain re-
PUPA (N=:2, mounted) gions where streams are torrential. South African
Cephalothorax: surface finely mgose, two minute pupae and Ethiopian and South African larvae are
pairs of dorsocentral setae, thoracic horn and pre- described here.
corneal setae as in Fig. 21, horn downturned, very
transparent with minute small points on distal half, PUPA (N = 4 mounted)
discernable under high power magnification; pre- Colour: mostly colourless; abdominal spurs brown.
corneal setae also very transparent, one long and Cephalothorax: cephalic tubercles small with short
two short. frontal setae; thoracic horn (Fig. 26) long and slen-
Abdomen: paired spine patches on tergites II-IV, der, the distal, pointed third section more strongly
as per Keyermaten & Stether; anal spur (Fig. 22) chitinized than the rest and with a few small
simple. points; wing sheath with prominent nose; setae:
LARVA (N=6 mounted) 2t6w)o, osnmealmlucanhtelpornogneortaalnsd,datrhkreeer tphraenctohreneoatlhser(tFwiog;.
Colour greenish in life; length c. 4 mm. two pairsofsmall dorsocentral closetogether.
s,
Head capsule: light brown; length 312 pm. Abdomen (Fig. 27): no shagreen, tergites II-VI
Antenna (Fig. 23): length 120 pm, AR 0.4; Lauter- with anterior pair of point patches, very wide on II
born organs reach base ofsegment 5. and III but width decreasing progressively so that
Labruin: similar to that of R. curtistyliis Goetghe- those on V and VI are only as wide as long;
&
buer (Pinder Reiss 1983). patches of small spines just before and after hook
Mandible (Fig. 24): all teeth dark brown, similar to row on tergite II; L setae very small or absent in
&
the generic definition (Pinder Reiss 1983) in- some positions; three LS setae on V-VIII; fringe on
cluding the large seta interna consisting of four anal lobe well developed; hook row on II small and
plumose branches. undivided; pedes spurii A and B absent, but a few
Mentiim: all teeth dark brown, width ofventromental small transparent spines at the usual position of A
plate 0.91 X width of mentum, specimen somewhat on IV; posterolateral spur large with accessory
flattened on slide. points on ventral surface (Fig. 28).
Maxilla (Fig 25): similar to that of R. fiiscus but
differing in small details such as the shape of the LARVA (N= 16 mounted)
lacinal chaetae. Headcapsule: length 325 pm.
Body: claws ofparapods all simple; procercal setae Colour: in fresh specimens the head and antennae
long and dark; anal tubules short with rounded glossy black, body greenish, claws light, and anal
tips. Bifid posterolateral setae are present on at setae dark brown; in mounted specimens the head
least some of the middle segments. These are plu- and antennae dark brown. Some South African
mose but transparent and difficult to discern on specimens medium brown.
mounted specimens. Head: dorsal surface, frontal apotome and labral
8 Harrison:TanylarsiniofSub-SaharanAfrica
sclerites 1 and 2 all finely granular. (Fig. 33), in some cases the two main branches are
Antenna (Fig. 29): AR 2.6. Segment 2 very short, adpressed so that the structure is not obvious;
blade extends to tip of segment 3; Lauterborn or- claws simple; anal tubules short with rounded tips.
gans prominent.
SPECIMENS EXAMINED
Labriinr. similar to that of R. curtistylus Goetghe-
beur (Finder & Reiss 1983). Premandible with two Larvae from upper Kechene River, 09“ 04'N
teeth and dense brush (Fig. 30). 38°45'E (Ers. 6K), 13 ix 83; Danka River, 07°05'N
Mandible (Fig. 31): all teeth brown, pecten man- 39°46'E (Ers. 34F), 20 i 84, collector ADH (in ZSM);
dibularis well-developed. South African specimens: from the Eastern Cape
Menlum (Fig. 32): median tooth with lateral notches Province, one larva from KuKowa Stream, tribu-
except in worn specimens, all teeth dark, width of tary of Slang-Mbashe River, (ECR 52) 7. xii 90;
ventromental plate the same as width of menturn. numerous larvae and four pupae from the Wilde-
Maxilla: very similar to that of R. fusciis (Fig. 20). bees River near Gleneig, 31°13'S 28°04E (ECR
Body: apart from some simple setae, segments 1 12C 1 & 2) 26 iii 93; from KwaZulu-Natal, one
IV-VIII bear lateral setae with two main branches larva from Bushmans River above Tugela conflu-
each bearing about six curved smaller branches ence, 28“46'S 30"l0'E (Bus 57Z (2) 05 x 2000.
Collectors F.C. de Moor and team (in AM).
Figs 18-33. Rheotcmytarsus spp.: 18-20, R.fiisais. 18-19, pupa: 18, thoracic horn and frontal setae; 19, anal spuron Vlll. 20, larva,
maxilla. 21-25, R. guineensis. 21-22, pupa: 21, thoracic horn andfrontal setae; 22, anal spuron VIII. 23-25, larva: 23, antenna; 24^
mandible; 25, maxilla. 26-33, R. montanus. 26-28, pupa: 26, antenna and frontal setae; 27, tergites ll-V; 28, anal spur on VIII
29-33,larva:29,antenna;30,premandible;31,mandible;32,mentum;33,lateralbodyseta.
AnnalsoftheEasternCapeMiiseinnsVol. 3(February2004): 1-15 9
+
NOTES NOTES
The South African pupa is very similar to that Habitat preference', must have bred in the Lake
described by Lehmann (1979) notably in the wide Busata as there was no other water nearby.
&
point patches on tergites II III. Distribution: Ethiopian Rift Valley.
Habitat preferences-, the larvae were found among Gejieral note on systematics: T. awashensis is dis-
stones in very rapid currents in upper mountain tinguished from all other known African species of
streams; they seemed to be better adapted to faster Tanytarsus (Freeman 1958; Ekrem 2001) and all
currents than other species ofRheotanytarsus. The the Palaearctic species described by Reiss & Fittkau
larval cases are similar to those of other species of (1971), by the combination of anal point with no
the genus but the arm-like extensions of the cases, spine patches; almost square superior volsella with
that support the silk strands, are comparatively a short beak and reduced digitus and short, brush-
much shorter. shaped median volsellae that meet centrally. Seg-
Distribution: Ethiopian Highlands, the Kivu dis- ment 5 of the labial palps is short. Following the
trict mountains of the Congo (ex-Zaire) and key in Ekrem (2001), Tawsahensis reaches couplet
KwaZulu-Natal and Eastern Cape Province (Drak- 7 but differs markedly from the two species keyed
ensberg Mountains), South Africa. there: from T. pallidulus Freeman in the shape of
the superior volsella (not roughly oval) and its me-
Tanytarsus awashensis sp. nov. dian volsella (not rounded) (Freeman 1958), and
(Figs 34-37) from T. atrocincus Goetghebuer, which has an L-
shaped superior volsella, a distinctly rounded me-
Material e.xaminecb. this description is based on
two drowned and damaged specimens. dian volsella and an almost club-shaped inferior
volsella (Freeman 1958).
ADULT MALE (N = 2 mounted) Etymology: from the Awash River, Ethiopia.
Close togeneric definition ofCranston etal. (1989).
Wij}g length'. 0.98-1.17 mm. Tanytarsus fliimineus sp. nov.
Colour, head with palps and antennae light brown; (Figs 38-43)
thorax and legs light brown, vittae, preepisternum ADULT MALE (N= 4 mounted)
and postnotLim brown, abdomen light brown with
Close to generic definition of Cranston et al.
no obvious markings.
AR (1989).
Head-. 0.71-0.76; frontal tubercles about five
Body length: 2.7 mm.
times as long as the width of the base; palps (Fig.
Wing length: 1.8 mm.
34): 195 jttm long; segments measuring 16, 31, 40,
Colour: whole body yellowish when preserved in
46, 62 jum (rather short); two subapical sensillae on
alcohol
segment 3. Head: AR 0.52-0.61; eyes with narrow dorsal ex-
Thora.v. no scutal tubercle; setation: lateral ante-
tension; no frontal tubercles; head setation with
pronotals nil, dorsocentrals 6, posterior prealars 1, seven verticals; palp segments measuring 30, 33,
scutellars 2 per side.
96, 105, 192 jttm, no subapical sensillaon segment 3.
Wings-, setae in the apical third of 14+5 and mi 3. Thorax: no scutal tubercle; setation: lateral ante-
Wings were in too poor a condition to determine
pronotals nil, dorsocentrals 9 uniserial, posterior
the setation ofveins.
prealars I, scutellars 4 per side.
Legs', scale of fore femur with long straight point;
Wings: no anal lobe; membrane setae dense around
combs of other legs all with spurs. Tarsi were miss-
ing in the specimens, so are&not described. twhiengresttipoffrtohme cwoisntga;ivnetionmsje+ta4:, sbpraarcsherioolvuemrIm,oRst22o,f
Hypopygiuin (Figs 35, 36 37): anal tergite bands
Ri 36, R4+5 50, numerous on other veins.
almost transverse and not meeting; anal point with
Legs: tarsi are not described as most were missing
setae but no spine patches, downturned; superior
from the material available; spur on foretibia short
volsella broad, almost square with short beak; digi- and curved. LR mid 0.7; sensilla chaetica on tar-
tus reduced; median volsellae short, brush-shaped
and meeting centrally (Fig. 36); inferior volsella somere I, midleg 6. &
parallel- sided; apodemes as in Fig. 37. Hypopygiuin (Figs 38, 39, 40, 41 42 ): anal tergite
bands not meeting; few small median anal setae;
SPECIMENS EXAMINED anal point downturned with large crests with long
2 d'(5' found drowned in Lake Busata, a fresh- spicules between (Fig. 39) with a few apical anal
water lake near Awash railway station, Ethiopia setae on either side; superior volsella short with at
8^^05'N 4(y’30'E, xi 84, both the holotype and para- least 20 dorsal setae and a patch of microtrichia at
type on the slide ETC.67A (the holotype being the lateral base; protruding digitus with no seta, but
specimen near the label); collector ADH (in ZSM). with a patch of microtrichia on its base (Fig. 40),
10 Harrison: TanytarsiniofSub-SaharanAfrica