A revision of Afrotropical Chyromyidae (excluding Gymnochiromyia Hendel) (Diptera: Schizophora), with the recognition of two subfamilies and the description of new genera
Author
Ebejer, Martin J.
text
African Invertebrates
2009
2009-12-31
50
2
321
321
http://www.bioone.org/doi/abs/10.5733/afin.050.0208
journal article
10.5733/afin.050.0208
2305-2562
7910603
Aphaniosoma ugabensis
sp. n.
Fig. 55
Etymology: The species name is derived from the
type
locality, Ugab River in
Namibia
. Diagnosis: Almost entirely yellow species with 2 pairs of long setulae on
fr
, only dark areas are small rectangular patch at anterior end of scutum just above occipital foramen and on metanotum. There are no external features to help in the identification of this species. Male postabdomen with long narrow pointed
psg
and short truncate
prg
;
surs
reduced to an inconspicuous lobe; pregential
st
with distinct midline ventral projection. Description:
Male
Head
: Entirely yellow, only ocelli ringed with black,
fr
broad, converging anteriorly so that at level of antennae it is about 0.7 as wide as at level of anterior
oc
, face small, depressed (carinal area not visible), eye narrow, oval, lying oblique, gena yellow, shrivelled, probably about half height of eye and having numerous yellow setulae, setae at vibrissal corner not seen, mouthparts yellow, 4 setulae on
fr
with 2 pairs of longer setulae, one above lunule and one in front of
oc
triangle, 2 short
orb
and in front of these 2 very short fine setulae,1
vti
and 1
vte
,
pvt
distinct and convergent,
oc
long, divergent, antennal segment 3 yellow, arista dark brown on apical 2/3 of segment 2 of arista.
Thorax
: Scutum and
scut
yellow with pale brown longitudinal stripes on posterior half of scutum and brown patch on extreme anterior scutum above neck,
mtn
dark brown, pleura yellow. Chaetotaxy: 1
pprn
, 1
posthu
, 1
ihu
, 2
ntpl
, 0+3
ia
, 2+3
acrs
, 3+4
dc
only the posterior one well-developed,
prpl
not seen, 1
pa
, 2 pairs of marginal
scut
, 1 katepisternal, 1 anepisternal, all setae pale, with shorter ones and setulae inconspicuous.
Wing: Hyaline and uniformly microtrichose, veins yellow, distance between R
2+3
to R
4+5
on costal margin about 0.5 that between R
4+5
and M
1+2
, distance between crossveins about equal to length of posterior crossvein and length of apical section of Cu about 3× length of posterior crossvein. Haltere yellow.
Fig. 55.
Aphaniosoma ugabensis
sp. n.
, ơ: (a) hypopygium, lateral; (b)
st
6, ventral. Scale bar = 0.15 mm.
Legs: Yellow and fine yellow setulose, tarsomere 5 of anterior leg brown.
Abdomen
: Yellow on all
tg
.
Postabdomen: Yellow with no distinctive external features.
Female
.
As male, but several specimens have the middle third of femora diffusely infuscated dorsally. (Postabdomen not dissected.)
Length
: ơ and ^body
1.2 mm
, wing
1.4 mm
.
Holotype
: ơ
NAMIBIA
:
Omaruru District
,
Ugab R.
,
2 km
W Brandberg Wes
,
20°58'05"S
:
14°06'36"E
,
23.x.1998
, sweeping,
E. Marais
(in glycerine,
NMNW
).
Paratypes
: 2ơ 8^same data as holotypes (in alcohol,
NMNW
)
.
Remarks. The
holotype
is not in good condition due to some shrivelling and broken setae.
Genus
Krifomyia
gen. n.
Type species:
Rhicnoessa minutissima
Bezzi, 1908: 200
, here designated.
Etymology: From Greek
krifos
(secret, secluded) and
myia
(fly), and refers to the genus being rare and unobtrusive.
Diagnosis: Well-developed, broad facial carina extending from lunule to just below antennae where it broadens laterally leaving antennae in deep pits; head short with rather inflated
fr
that has parallel margins and which, in profile, is visible all along eye margin from vertex to antenna, gena higher than height of eye which, in profile, is round to oval and small relative to head size, when compared to other genera;
pvt
present,
ihu
minute,
posthu
short,
sa
and katepisternal setae absent, veins R
4+5
and M
1+2
converging slightly towards apex, apicoventral seta on mid tibia present.
Description:
Head
: Rectangular in profile and almost twice higher than long;
fr
broad and parallel-sided, protruding above and in front of eye margin when seen in profile; finely setulose; gena deep, at middle equal to or greater than height of eye and with wide post genal dilation; fine pale setulose, postgenal seta absent; face long with very broad carina extending from lunule to just below antennae, where it widens; thus, antennae lie in deep fossae, with segments 1 and 2 very short, segment 3 rounded except for shallow dorsal excavation near insertion of arista; arista with 3 segments and shorter than usual for the family; 2 short reclinate
orb
, 1
vti
and 1
vte
, both shorter than usual for this family,
oc
setae divergent,
pvt
minute and parallel, sometimes absent, few postocular setulae in one row; mouthparts all yellow, well-developed with long proboscis, geniculate labella and narrow elongated palp.
Thorax
: A little shorter and broader than usual for the family. Chaetotaxy: 1 short
pprn
and 1 short
posthu
, a minute but distinctly incurved
ihu
, 2
ntpl
, 1
pa
, 1 short
post ia
, 1
dc
,
acrs
very short and in more than 2 irregular rows, 1 anepisternal closer to upper margin; absent
sa
and katepisternal setae;
scut
with 1 pair basals and 1 pair subapicals, all about as long as
dc
.
Wing: Hyaline, veins very pale yellow, only Cu along discal vein a little darkened;
RM
stem vein thickened; anal cell pointed apically along anal vein; costal setulae all fine and pale; R 2+3 and R 4+5 very slightly divergent. Haltere yellow with creamy white knob. Legs: Entirely dull yellow with short pale setulae, only claws darkened; apicoventral seta of mid tibia present and longer than diameter of tibia at apex; legs without dilated segments or special modifications.
Abdomen
: All
tg
normally sclerotized and with a few very fine setulae scattered thinly on all segments, but on
tg
6, which is as long as
tg
5, stronger and more numerous setulae present.
Postabdomen: Male hypopygium very small with reduced appendages, short
ph apd
and markedly simplified
ph
compared to the rest of the family. Female abdomen with 8 segments, sclerotized
st
8; 2 unpigmented
s
.
Remarks. This genus belongs to the
Aphaniosominae
because of the following combination of characters: absent incurved lower
orb
, concave
ocp
, long apicoventral seta on mid tibia, anepisternal seta above middle of posterior margin, incurved
ihu
setula, absent hemispherical
ep
. With
Paraphaniosoma
it shares the
post ia
seta and more than two rows of scutal setulae between
dc
lines. However, it differs in the much simplified hypopygial structures, absent
sa
and katepisternal setae, markedly different shaped head, well-developed proboscis and in the wing having the costal vein with spinescent setulae and a thickened
hu
crossvein.
Distribution: Atlantic coast of southern Africa (
Namibia
) (
Fig. 70
).
Ecology:
Krifomyia
, known from a single species so far, is rare and by all accounts a rather cryptic inhabitant of hot dry coastal regions.