A new species, Ceriana dirickxi (Syrphidae, Eristalinae, Cerioidini), is described and illustrated from Zimbabwe. A key to the Afrotropical species of Ceriana is given.
Author
F. Christian Thompson
text
Mitteilungen der Schweizerischen Entomologischen Gesellschaft
2013
86
145
150
journal article
10.5169/seals-403067
Ceriana
dirickxi Thompson
,
sp.
nov.
Description
. Female (
Figs
1-
2
). Head. Reddish brown; face dark brown with broad yellow sublateral vitta and narrow reddish medial vitta, tubercle reddish; frons light reddish except small yellow macula lateral to junction of frons and face, sparsely white pilose; frontal prominence reddish brown; vertex reddish brown, sparsely white pilose; occiput reddish brown, white pollinose and pilose ventrally, more sparsely pollinose dorsally; gena yellow except reddish brown on medial
1
/
3
, white pilose. Antenna dark reddish brown, black pilose; arista yellow; antennal ratio:
1.7
" 1.0:1.0:
1.3
:
0.2
; antennifer ratio:
3.3
.
Fig. 2.
Ceriana éliríckxi
Thompson
,
sp. nov.
, holotype female. Lateral habitus.
Thorax. Postpronotum reddish brown, pale pilose; scutum black on medial
2
/
3
, reddish brown laterally, sparsely gray pollinose, short appressed yellow pilose, with some black pile medially; pleuron reddish brown except pectus darker; scutellum reddish brown, pale pilose; calypter white; halter yellow. Legs light reddish brown except coxae darker, pale pilose. Wing: tricolored, brownish orange yellow along anterior margin on basal
2
/
3
extending posteriorly to vein CuA on basal
1
/
5
and to vein Rs elsewhere, brownish black except hyaline on basomedial
1
/
3
and along posterior margin; vein R
4
+
5
sinuate but without a spur; completely microtrichose.
Abdomen. Dark without pale yellow maculae, short black pilose; l
“
tergum black;
2
“
d tergum dark reddish brown except with black triangular area and based on posterior
2
/
3
with apex on anterior margin;
3111
tergum narrowly reddish brown on basolateral
1
/
4
, black elsewhere;
41
h tergum black except for small reddish brown triangular area on apical
1
1
//
/
1
4
;g
5111
tergum reddish brown, pale pilose; sterna black, black appressed short pilose medially, yellow pilose laterally; abdominal segmental ratio. l. l.l. 0: l.
3
: l.
7
:
0.3
; abdominal petiole ratio: l.0: 1.0:l. l
Length. Body,
13.6
mrn, wing, 12.0 mm.
Differential Diagnosis
.
Ceriana dirickxi
runs to
Ceriarıa ponti
Thompson in the last key to Afrotropical cerioidines (Thompson
2013
a:
73
), and is quite similar in stature to that species but is quite different in coloration.
C.
ponzi
has a dark abdomen with a bright continuous yellow sublateral margin, whereas
C
.
dirickxi
has an unicolorous, brownish red to black abdomen.
C cliríckxi
was collected at the same locality and by the same collector as the only two known specimens of
Ceriana dilatipes
Brunetti. Hence
, while one may think that these are only color variants of the same species, they are quite distinct:
C
.
dilarípes
has broad apical yellow fascia on
2
nd,
3
rd and
4
'“ terga, a yellow vitta on the laterotergum as well as a bare alula, whereas
C
.
dirickxi
lacks these yellow maculae and has a microtrichose alula.
Type
Material
.
Holotype
female
pinned with the following labels:
<<
SAW MILLS // S. Rhodesia
//
10.12.1926
//
R.H.R. Stevenson
» [with a narrow black bor- der on label]; <<
NMSA-DIP
/
44959
;» and <<
Holotype
//
Ceriana
//
dirickxi
// Thompson
2013
» [hand-written on orange card stock] deposited in
National Museum of South Africa
, Bloemfontein.
Type
locality
.
Zimbabwe
,
Saw Mills
,
19
°
35
’
S
,
028°
12
’E
Distribution
. Zimbabwe.
Etymology
. Traditionally cerioidine species are named after distinguished dipterists. So. I am delighted to name this distinctive species after my former colleague, Henri Dirickx (
1928
04.23 —
2013.02
.05), who recently passed on. I am only sorry that I did not do this sooner. Henri was born in Belgium, Anvers [the original home of another flower fly worker, Marc De Meyer] and was trained as a civil engineer. Later he worked for the United Nations Economic Commission in Geneva and retired in
1988
. In his retirement, he worked on Afrotropical flower flies. He published a detailed catalog of the species (Dirickx
1998
), summarizing the prior work on these flies as well as revisions of various genera:
Spheginobaccha
(Dirickx
1995
)
,
Melanostoma
(Dirickx
2001
)
&
Allobaccha
(Dirickx
2010
)
. Also, he published a review of fossil flower flies (Dirickx
2009
) and a couple of other papers, all of his papers on flower flies are listed in the reference section (Dirickx 1994, 2009; Dirickx
et al
.
1996
; Dirickx & Obrecht
2007
; Dirickx & Steffan
1992
; Maibach
et al
.
1995
). Finally, I and Martin Hauser are in the process of finishing a joint paper with him on Madagascar cerioidine flies. Unfortunately, he passed away too soon to do more.