Discovery of Systenus in the Afrotropical Region with a description of a new species (Diptera: Dolichopodidae)

2009·0.22 MB·

by  I. Ya. Grichanov

Zoosystematica Rossica, 18(2): 285–290 25 DecembeR 2009
Discovery of Systenus in the Afrotropical Region with a description
of a new species (Diptera: Dolichopodidae)
I.Ya. GrIchanov & M.B. MostovskI
I.Ya. Grichanov, All-Russian Institute of Plant Protection, Podbelskogo Str. 3, Pushkin, St. Petersburg 196608,
Russia. E-mail: [email protected]
M.B. Mostovski, Natal Museum, P. Bag 9070, Pietermaritzburg, 3200 South Africa; School of Biological &
Conservation Sciences, University of KwaZulu-Natal, P. Bag X01, Scottsville, 3209 South Africa; Paleontological
Institute, Russian Academy of Sciences, Profsoyuznaya Str. 123, Moscow 117997, Russia.
E-mail: [email protected]
The genus Systenus Loew, 1857 is recorded from Afrotropical Region for the first time. A de-
scription of a new species, Systenus africanus Grichanov sp. nov., and notes on females of
another probably new Afrotropical species are provided. The genus is considered now as cos-
mopolitan. A key to species and species groups of the Systenus worldwide is compiled.
Key words: South Africa, Diptera, Dolichopodidae, Systenus, new species
INTRODUCTION on females of other probably new Afrotropi-
cal species.
Until recently, the genus Systenus Loew,
1857 has been only known from the Hol-
MATERIAL AND METHODS
arctic Realm. Several new Palearctic (Ne-
grobov & Shamshev, 1985; Macgowan, The left lateral view of the hypopygium,
1997; Olejníček & Kozánek, 1997; Gricha- or male genital capsule, is illustrated for the
nov, 2002; Negrobov, 2005), Australian new species. In describing the hypopygium,
(Bickel, 1986), Neotropical (Naglis, 2000) ‘dorsal’ and ‘ventral’ refer to morphologi-
and Oriental (Yang & Gaimari, 2004) spe- cal position prior to rotation and flexion.
cies have been described during the last Thus, in figures showing a lateral view of
decades. The genus is also present in the the hypopygium, the top of the page is mor-
Nearctic region, but has been yet unknown phologically ventral, while the bottom is
from the Afrotropics. Following Robin- dorsal. Morphological terminology follows
son (1970), Negrobov (1991) regarded the Robinson and Vockeroth (1981), Stucken-
genus in Systeninae. Bickel (1986) and berg (1999), and Grichanov (2007). The
Evenhuis (1994) placed the genus in the relative lengths of the podomeres should be
subfamily Medeterinae. A key to all the regarded as representative ratios and not
species then known was provided by Stey- measurements.
skal (1970). The last key to Palearctic spe- The holotype of the new species and
cies of Systenus was published by Negrobov other material examined are housed in the
(2005). Keys to Australian and Neotropical collection of the Natal Museum, Pietermar-
species were provided by Bickel (1986) and itzburg, South Africa (NMSA).
Naglis (2000). After the description of the
first Afrotropical species in this paper, Sys- Systenus africanus Grichanov, sp. nov.
tenus africanus Grichanov sp. nov., the ge- (Figs 1–4)
nus is considered now as cosmopolitan with
Holotype (in glycerol). Male ; South Africa:
30 extant species. Here we compile a key to KwaZulu-Natal Prov., Kosi Bay (2632DD), 30
species and species groups of the Systenus Nov. – 12 Dec. [1982?] (NMSA).
world fauna for the first time and give notes Description. Male.
© 2009 Zoological Institute, Russian Academy of Scienсes
286 I.Ya. GrIchanov & M.B. MostovskI. DIscoverY of sYstenus In afrotropIcal reGIon
Head. Vertex, frons, face dark metallic Abdomen metallic, mainly brown; 1st
blue-green; face under antenna half as wide tergum yellow; 2nd tergum yellow except
as postpedicel height; palpi yellow with distal margin; 3rd tergum yellow ventrally;
strong apical seta; proboscis brownish, pro- posterior margin of first tergum with row of
jecting anteriorly, keel-like; single row of long brown setae; 2nd to 6th sterna membra-
strong pale postoculars; antennal scape and nous or only weakly sclerotised, somewhat
pedicel yellow, postpedicel mostly brown, recessed. Segment 7 elongate-pedunculate,
broadly yellow at base and ventrally; pedi- brownish; segment 8 brown, with setae. Hy-
cel short, with ring of apical setae; postpedi- popygium brownish; hypandrium fused with
cel large, tapering, 3 times as long as basal epandrium, asymmetrical; two peduncu-
width, densely pubescent; stylus short, bare. late epandrial setae; cercus yellow, long and
Length ratio of scape to pedicel to postpedi- slender, about as long as epandrium, bearing
cel to stylus, 40:10:165:80. subapical tooth and yellow setae; sursty-
Thorax. Dorsum metallic dark-brown; lus moderately long and broad, flat, yellow,
pleura brown with black spot on pteropleu- shorter than cercus, with a dorsal and an
ron; metepimeron yellow; posterior third of apical projections bearing long setae.
mesonotum distinctly flattened; thoracic Measurements (mm): body length 3.3,
setae brown; biseriate acrostichals of equal antenna length 0.9, wing 3.0, wing width
length; posterior two pairs offset laterad; 6 0.5, hypopygium length 0.6.
strong dorsocentrals, decreasing in size an- Etymology. African in Latin.
teriorly; 2 pairs scutellars, laterals hairlike, Diagnosis. The new species resembles
about 1/4 length of medians; 1 pale proepis- a Palearctic species S. tener Loew, 1859
ternal just above fore coxa. (Grichanov, 2002; Negrobov, 2005) that
Legs including coxae yellow, 5th tarsom- has a narrow rather than broad surstylus,
eres darkened; fore and mid coxae with a pointed rather than widened at apex cer-
pale anterior setae; hind coxa with 1 strong cus, and an entirely black antennal post-
pale lateral bristle; major leg setae black or pedicel. The hypopygium morphology has
brown; mid tibia with strong anterodorsal some similarity with a number of Neotropi-
and posterodorsal at 1/5, weaker anterodor- cal species, and S. flaviatus Naglis, 2000 is
sal and posterodorsal at 2/3, an apical ring a species closest to S. africanus. However,
of 4 bristles; hind tibia with row of 4 very the two species differs in morphology of the
short dorsal setae, with short anterodorsal wing, antenna, hypopygial cercus and sur-
at base; length ratio of fore tarsus (segments stylus (see the key below).
from first to fifth), 61:38:25:11:10; same ra-
tio for mid leg, 103:55:38:23:20; same ratio Systenus species unidentified
for hind leg, 45:90:45:28:20.
Material examined (in alcohol). Three females;
Wing simple: R and R diverging to
2+3 4+5 South Africa: KwaZulu-Natal Prov., Kosi Bay
wing apex; R slightly bowed outwards;
4+5 (2632DD), 30 Nov. – 12 Dec. [1982?] (NMSA);
M with weak curvature behind middle of
1+2 two females, South Africa: KwaZulu-Natal
distal part; both veins distinctly convergent
Prov., Louwsburg, Sanyati Farm, 27°34´00´´S
in third quarter of wing. M joining costa 31°17´57´´E, alt. 1090 m, 30 Oct. – 18 Dec. 2005,
1+2
at wing apex. Ratio of part of costa between Malaise trap, coll. M. Mostovski (NMSA).
R and R to this between R and M Remarks. All specimens collected at Kosi
2+3 4+5 4+5 1+2
to m-cu to distal part of CuA , 40:12:23:65. Bay are rather lightened due to long-term
1
Crossvein m-cu straight, forming right an- storage in alcohol; pollen on their heads and
gle with CuA and with M longitudinal the thorax is indistinguishable. Females
1 1+2
veins. Anal vein fold-like; anal lobe present; taken from the same trap as Systenus afri-
alula absent. Lower calypter yellow, with canus male holotype belong apparently to
pale setae. Halter yellow. two species, which may be different from
© 2009 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 18(2): 285–290
I.Ya. GrIchanov & M.B. MostovskI. DIscoverY of sYstenus In afrotropIcal reGIon 287
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© 2009 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 18(2): 285–290
288 I.Ya. GrIchanov & M.B. MostovskI. DIscoverY of sYstenus In afrotropIcal reGIon
Figs 2–4. Systenus africanus Grichanov sp. nov., holotype : antenna (2), wing (3), hypopygium (4).
Scale bars: 0.2 mm (2), 0.2 mm (3), 0.5 mm (4).
© 2009 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 18(2): 285–290
I.Ya. GrIchanov & M.B. MostovskI. DIscoverY of sYstenus In afrotropIcal reGIon 289
the male. They differ between each other in scholtzi (Loew, 1850), Nearctic minutus (Van
m-cu to distal part of CuA ratio, postpedi- Duzee, 1913) and Neotropical raptor Becker
1
cel length, mid coxa coloration (yellow or – M and R veins gently convergent or par-
1+2 4+5
allel, their tips separated by more than half
brown) etc. Females taken from Louwsburg
length of m-cu . . . . . . . . . . . . . . . . . . . . . . . . . . 6
(Sanyati Farm) differ in darker body, dis-
6. Wing apex white, preceded by blackish trans-
tinctly fumose wing and brownish hind fe-
verse bar (Nearctic) . . . apicalis Wirth, 1952
mur. These characters could be related to a
– Wing hyaline or slightly, evenly infumate . . . 7
weaker fixing agent used in the last locality.
7. Antennal stylus approximately as long as
The specimens from Sanyati Nature Farm postpedicel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
were collected together with Meuffelsia er- – Stylus much shorter than postpedicel . . . . . 9
asmusorum Grichanov, 2008 in the primar- 8. Antennal scape and pedicel yellow, postpedi-
ily indigenous riverine bush; the habitat cel mostly black-brown, broadly yellow at
was described by the authors (Grichanov base (Palearctic) . . . . vasilii Grichanov, 2002
– Antenna wholly black, at most yellowish on
& Mostovski, 2008). It is worth mention-
mesal side of pedicel and at base of postpedi-
ing that all six new Neotropical species of
cel (Nearctic) . . . . . . . . . . . . . . . . . . . . . . . . . albi-
the genus were taken from a single Malaise
manus Wirth, 1952, eucercus Steyskal, 1970
trap (Naglis, 2000). They were described by
9. Antenna wholly black . . . . . . . . . . . . . . . . . . . .
males only. Nevertheless, Palearctic S. fla-
. . . . . . . . . . . . . . . . . . . . . . .Australian australis
vimaculatus Negrobov, 2005 and Neotropi- Bickel, 1986, curryi Bickel, 1986, Neotropical
cal S. raptor Becker, 1922 are known by fe- nigriatus Naglis, 2000, rafaeli Naglis, 2000
males, while some other species are known and Palearctic bipartitus (Loew, 1850), leu-
by males only. curus Loew, 1859, viklundi (Grichanov, 2004)
– At least scape partly yellow (including fe-
male of an undescribed Australian species) . .
Key to species and species groups
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
of Systenus
10. At least first two abdominal segments yellow
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1. M and R veins distinctly divergent from
1+2 4+5 – Abdomen entirely dark . . . . . . . . . . . . . . . . . 12
base to apex (Nearctic) . . . . . . . . . . . . . . . . . . . . .
11. Distal part of CuA nearly 3 times longer
. . . . . . . . . . . . . . . californicus Harmston, 1968 1
than crossvein m-cu; antennal stylus half as
– M and R veins convergent or parallel in
1+2 4+5 long as postpedicel (Afrotropical) . . . . . . . . . .
distal half . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
. . . . . . . . . . . . . . . africanus Grichanov, sp. nov.
2. Postpedicel very long, at least 5 times longer
– Distal part of CuA slightly longer than cross-
than high at base, with stylus about as long 1
vein m-cu; antennal stylus 1/5 as long as post-
as postpedicel; antennal stylus with apical
pedicel (Neotropical) . . . . . . . . . . . . . flaviatus
flag (males) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
12. Postpedicel broadly yellow at base and ven-
– Postpedicel relatively short, at most 3.5
trally (Neotropical) . . . . . . amazonicus Naglis,
times longer than high at base; antennal sty-
2000, beatae Naglis, 2000, rarus Naglis, 2000
lus without apical flag . . . . . . . . . . . . . . . . . . . 5
– Postpedicel entirely black . . . . . . . . . . . . . . 13
3. M and R veins strongly convergent,
1+2 4+5 13. Hind femur broadly black at apex (Palearc-
their tips separated by not more than 1/3
tic) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . tener
length of m-cu (Palearctic) . . . . . . . . . . . . . . . .
– Hind femur wholly yellowish (Nearctic) . . . .
. . . . . . . . slovaki Olejnichek & Kozanek, 1997
– M and R veins gently convergent, their . . . . . . . . . . . . . . . . . . . . . shannoni Wirth, 1952
1+2 4+5
tips separated by more than half length of
m-cu (Oriental) . . . . . . . . . . . . . . . . . . . . . . . . . . . ACKNOWLEDGMENTS
. . . . . . . . . . . . . . sinensis Yang & Gaimari, 2004
5. M and R veins strongly convergent, Our appreciation extends to Thea and Cobus
1+2 4+5
their tips separated by not more than 1/3 Erasmus (Sanyati Nature Farm), who allowed
length of m-cu . . . . . . . . . . . . . . . . . . . . . . collecting on their property, professionally
Palearctic flavimaculatus Negrobov, mallochi helped with servicing a Malaise trap, and pro-
Macgowan, 1997, pallipes (von Roser, 1840), vided additional information on the local floral
sachalinensis Negrobov & Shamshev, 1985, assemblage and weather conditions over the col-
© 2009 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 18(2): 285–290
290 I.Ya. GrIchanov & M.B. MostovskI. DIscoverY of sYstenus In afrotropIcal reGIon
lecting period at Sanyati. We also grateful to V. Negrobov, O.P. 2005. On species of the genus
Kolyada (Zoological Museum, Moscow) for his Systenus (Dolichopodidae, Diptera) from
invaluable help in sorting bulk samples when he Palearctic Region. Zoologicheskii zhurnal,
was visiting the Natal Museum. Senior author 84(11): 1421–1424. (In Russian with Eng-
has got financial support from NMSA for his lish summary).
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data on Dolichopodidae (Diptera) fauna of
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© 2009 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 18(2): 285–290