Systematics of Robustagramma, a new genus of New World Sphaeroceridae (Diptera)
Author
Marshall, Stephen A.
Author
Cui, Yongsheng
text
Zootaxa
2005
2005-07-29
1026
1
1
122
https://biotaxa.org/Zootaxa/article/view/zootaxa.1026.1.1
journal article
10.11646/zootaxa.1026.1.1
11755334
5049813
3EDC6787-C73B-4969-BA06-022D0532364F
Robustagramma atratum
Cui and Marshall
,
new species
(
Figs. 2–8
,
363
)
Body length
1.7–2.2 mm
. General color brown to black, lightly pollinose, except shining abdomen and tibiae.
Head: Face, gena, antenna and lower frons reddish to dark brown. One pair of conspicuously strong interfrontal bristles and one pair of interfrontal setulae between interfrontal bristles and ptilinal suture. Two orbital bristles, anterior orbital bristle
ca
. 2/3–3/4 as long as posterior. Postocellar bristles over half as long as postvertical bristles, convergent or cruciate. Eye height
ca
.1.8–2.1 times genal height. Aristal hairs
ca
. 2 times as long as basal width of arista. Palpus with several thin ventral bristles and two stout preapical ventral bristles; preapical palpal bristles 2.0–2.3 times as long as greatest width of palpus.
Thorax: Dorsocentral bristles in 3 (two postsutural and one presutural) pairs, anterior pair similar in length to middle prescutellar acrostichal bristles. Acrostichal setulae in 8 rows between anterior postsutural dorsocentral bristles. Posterodorsal katepisternal bristle very long, over 4/5 as long as distance between bristle base and wing base; anterodorsal katepisternal bristle very small. Halter knob brown; stem yellow. Wing clear except for lightly pigmented anterior marginal area.
First costal sector thinner than second costal sector; basal 1/6–1/4 of second costal sector distinctly dark. Ratio of second to third costal sector
ca
.0.45.
Costa
ending at or near wing apex, extending past R
4+5
by 1–3 vein widths. Distal quarter of R
2+3
abruptly curved forward. Discal cell with an angulate posterior corner and a long stump of vein CuA
1
. Tarsi and fore tibiae reddish yellow except for brownish pretarsi. Mid tibia with a single posterodorsal proximal bristle, an anterodorsal bristle near middle, and an anterodorsal, dorsal and posterodorsal distally; dorsal bristle small; an additional smaller anterodorsal bristle anterior to dorsal bristle. Mid femur with a row of anterior bristles in distal half, a small posterodorsal apical bristle, and a row of strong anterodorsal setulae. Mid tibia of male with an apicoventral bristle and two rows of strong ventral setulae in distal half. Mid femur of male with a row of weak anteroventral and a row of 5–6 posteroventral bristles on basal third.
Male abdomen: Tergites uniformly dark to black and similar in length. Bristles of tergites 4, 5 and epandrium very long, lateral marginal bristles on tergite 5 longer than tergite 5. Epandrial length dorsomedially 0.25–0.33X length of sternite 8. Sternite 5
ca
. 1.5 times length of sternite 4, with two dense patches of stout bristles on central area. Cercus short, subtriangular in shape. Surstylus reddish yellow to brownish, characteristic in shape with two broad, setulose lobes (fig. 2, 3). Postgonite with a thick distal half; ejaculatory apodeme very small.
FIGURES 2–8.
Robustagramma atratum
sp. nov.
: 2, posterior view of male terminalia; 3, lateral view of male terminalia; 4, lateral view of male internal genitalia; 5, male sternite 5; 6, dorsal view of female terminalia; 7, ventral view of female terminalia; 8, spermathecae.
Female abdomen: Tergites 1–7 uniformly pigmented and entire. Sternite 8 entire. Spermathecae with distal portion larger than basal portion. Paired spermathecae with ducts
ca
. 1.5 times length of spermatheca.
Holotype
(
♀
,
INBC
) and
paratypes
(
2 ♂
,
1 ♀
,
DEBU
):
COSTA RICA
:
Puntarenas
. Monteverde Biol. Res.,
1500m
, cloud forest,
11–13.vi.2000
,
S. A. Marshall.
Other
paratypes
:
Same
data as holotype, but dated
13.vi.2000
(
1 ♂
,
INBC
)
;
12.vi.2000
, on dung (
1 ♀
,
INBC
)
.
COSTA RICA
:
San José
.
Zurquí
de Moravia
,
1600m
,
v.1991
,
P. Hanson
(
1 ♀
,
INBC
)
.
Etymology: The specific epithet, from the Latin for “dressed in black”, refers to the color of this species.