New chironomid flies in Early Cretaceous Lebanese amber (Diptera: Chironomidae)
Author
Veltz, Isabelle
Author
Azar, Dany
Author
Nel, André
text
African Invertebrates
2007
2007-04-30
48
1
169
191
journal article
10.5281/zenodo.7667523
2305-2562
7667523
Lebanorthocladius furcatus
sp. n.
Figs 9–12
Etymology: After the forked gonostylus, characteristic of the male.
Description: Head
0.12 mm
long. Ocelli absent. Antenna
0.56 mm
long, almost 5 times length of head, distinctly hairy, with 13 flagellomeres covered with long setae (shortest
0.04 mm
, longest
0.2 mm
), scape broad and short, rounded, pedicel very short,
Fig. 9.
Lebanorthocladius furcatus
gen. et sp. n.
, holotype 5B, general habitus, scale bar = 0.5 mm.
flagellomere 13 very long (
0.07 mm
). Eye bare, with a small dorso-medial extension, with 3 rows of ommatidia at minimum width. Clypeus with few dorsal setae. Mouthparts lacking functional mandible; 4 palpomeres with numerous setae, all of approximately the same length. Postocular, frontal, inner vertical and outer vertical setae not visible, possibly absent.
Thorax
0.46 mm
long,
0.38 mm
high; postnotum without visible setae, and no visible longitudinal median groove; surface of scutellum without visible setae; acrostichals and dorsocentrals not visible, probably absent; scutal tubercle present; scutum without median longitudinal groove; epimeron II, posterior mesanepisternum II and dorsal antepronotum bare; no lanceolate setae on scutum; antepronotal lobes not widely separated; anapleural suture distinct.
Wing macropterous,
0.84 mm
long,
0.26 mm
wide, hyaline, membrane bare.
Costa
ending just beyond insertion of last branch of radius, distinctly shorter than cross-vein RM. Radius with only 3 branches R
1
, R
2+3
, and R
4+5
; R
2+3
well separated from R
1
and R
4+5
, R
2+3
not forked into R
2
and R
3
, ending in costa; R
1
and R
4+5
elongate, separated from costa until apex; area between costa and R
4+5
broad. Only M
1+2
and M
3+4
present; cross-vein MCu absent; Cu
1
nearly straight. Anal vein An
2
absent; squama without setae. Halter
0.12 mm
long.
Figs 10–12.
Lebanorthocladius furcatus
gen. et sp. n.
, holotype 5B: (10) wing, scale bar = 0.5 mm; (11, 12) dorsal and ventral aspects of male genitalia, scale bar = 0.1 mm.
Fore femur length
0.34 mm
, tibia
0.36 mm
, tarsus
0.62 mm
; mid femur
0.34 mm
, tibia
0.44 mm
, tarsus
0.5 mm
; hind femur
0.38 mm
, tibia
0.48 mm
, tarsus
0.6 mm
. All tarsomeres of fore, middle and hind legs cylindrical, not cordiform; first tarsomere of fore leg distinctly shorter than fore tibia. Hind tibia with one spur and a comb comprised of basally separated spines. Fore coxa not enlarged.
Abdomen
1 mm
long,
0.16 mm
wide. Gonostylus hinged to gonocoxite and folded inward; short and bifurcate. Gonocoxite with numerous long setae, elongate. Superior (?) volsella large, digitiform; no median volsella and no apparent inferior volsella.Anal point sharp and long,
0.4 mm
wide at base,
0.07 mm
high.
Holotype
: Specimen 5 B, male.
LEBANON
:
Mont Lebanon district
[
Mouhafazit Jabal Loubnan
]: Hammana / Mdeyrij, Caza Baabda; Early Cretaceous (
D. Azar
coll.).
Other material studied: Specimen 574 I, male, with genital organs missing, from the same locality and possibly also belonging to this species.
Discussion: This species belongs to the subfamily
Orthocladiinae
because of the following characters: wing present; cross-vein MCu absent; first tarsomere of fore leg distinctly shorter than fore tibia; hind tibia with one spur and a comb comprised of basally separated spines; gonostylus hinged to gonocoxite and folded inward; antepronotal lobes not widely separated; fore coxa not enlarged; anapleural suture distinct (
Oliver 1981
;
Oliver & Dillon 1989
). Except for the key to Holarctic genera of
Cranston
et al.
(1989)
, and the key to Palaearctic genera in
Saether
et al.
(2000)
, there is no recent world revision of the orthocladiine genera.
Few recent genera have a double, forked, or broad triangular gonostylus, as in
Lebanorthocladius
gen. n.
, viz.
Aagaardia
Saether, 2000
,
Brillia
Kieffer, 1913
,
Diplosmittia
Saether, 1981
,
Plhudsonia
Saether, 1982
,
Propsilocerus
Kieffer, 1923
(=
Tokunagayusurika
Sasa, 1978
),
Zalutschia
Lipina, 1939
, some
Chaetocladius
Kieffer, 1911
, some
Parachaetocladius
Wülker, 1959
, and one
Orthocladius
van der Wulp, 1847
.
Brillia
,
Diplosmittia
,
Plhudsonia
and
Propsilocerus
have a double gonostylus.
Lebanorthocladius
differs from all of the other genera by the following combination of characters: straight Cu
1
, very short costal extension, and R
4+5
ending opposite to apex of M
3+4
. All genera except
Aagaardia
also have setae on squama and all lack a scutal tubercle. The volsellae are of the
type
found in the
Brillia
group of genera, present, for instance, in
Eurycnemus
van der Wulp, 1874
(Fittkau 1974;
Saether 1982
, 2000
b
;
Chaudhuri & Bhattacharyay 1989
;
Cranston
et al.
1989
;
Kawai 1991
;
Kobayashi & Sasa 1991
;
Niitsuma 1991
;
Saether & Wang 1992
, 1996;
Andersen & Saether 1993
a
,
b
;
Saether &Andersen 1993
, 1995;
Saether & Ferrington 1993
;
Kobayashi 1994
; Boothroyd 1994, 1999;
Boothroyd & Cranston 1994
;
Epler & de la Rosa 1995
;
Ferrington & Saether 1995
;
Oliveira
et al.
1995
;
Saether & Kristoffersen 1996
;
Harrison 1997
, 2000;
Wiedenbrug & Fittkau 1997
; Wang & Saether 1998, 2002;
Cranston & Edward 1999
;
Saether & Ekrem 1999
;
Yamamoto 1999
;
Cranston 2000
;
Maheshwari & Maheshwari 2001
;
Mendes
et al.
2004
a
,
b
).