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
Paraphaniosoma sexvittatum
(
Lamb, 1914
)
,
comb. n.
Figs 58
,
59
Aphaniosoma sexvittata
:
Lamb 1914: 356
.
The original description of
P
.
sexvittatum
, although accurate, lacks detail and would not satisfactorily differentiate this species from other undescribed species I have seen from the East Palaearctic and Oriental regions (
Papua New Guinea
,
Malaysia
, Taiwan). Therefore, a more detailed redescription is provided with figures of the male and female postabdomen.
The detailed description of the characters given by
Lamb (1914)
, and the characters given in the key to genera provided in this article, serve to identify this species with relative ease. Additional characters and illustrations are given below, based on more material of this species from Aldabra (
Seychelles
).
Redescription:
Male
.
Head
: Yellow,
oc
triangle yellow, but ocelli ringed with black;
ocp
brown except for broad postocular margin;
fr
narrow, at level of anterior
oc
about 0.4 width of head and at level of antennae about 0.6 width of that at level of anterior
oc
; eye elongate oval, lying oblique. Chaetotaxy: 2 reclinate
orb
with 3 short pale setulae in front, 1
vti
and 1
vte
, minute
pvt
(absent in some specimens); ocellars long and divergent with pair of short setulae behind these in between posterior ocelli; 14 setulae scattered on
fr
, but 6 of these in front of
oc
triangle about as long and strong as anterior
orb
; postoculars in one row; gena pale yellow and very pale yellow setulose with stronger setulae on oral margin, gena at middle about 0.5 highest diameter of eye; mouthparts yellow, palpus narrow; face mostly membranous with a very thin and shallow facial carina; antenna yellow, second segment paler with very thin short and pale dorsal seta; arista all brown, bare.
Thorax
: Yellow, paler on pleura, scutum with 6 longitudinal dark brown stripes all separated from each other and from a brown patch at anterior end of scutum; middle stripes run from just anterior to transverse suture to
scut
, lateral to these and from behind transverse suture, a stripe runs between
dc
and
ia
lines of setulae on each side and another between
sa
and
ia
rows; a brown tiangular spot lies medial to
pprn
and confluent or narrowly separated from anterior dark scutal patch; anepisternum with brown streak at its lower margin and anepimeron with brown streak at its anterior margin,
mtn
brown,
scut
mostly yellow except for broad pale brown patch on disc and dark brown spot on sides at base. Chaetotaxy: 2
pprn
, 2
ntpl
, 1
posthu
, 1 short
ihu
, 1
pra
, 0+2
dc
(anterior one short), 1 short
sa
, 1 long
pa
and 1 long
post ia
, scutal setulae in 4–6 irregular rows between
dc
lines, with stronger
prscut
pair,
scut
with basal and subapical pair, 1 anepisternal at upper hind margin and 1 katepisternal at upper hind corner.
Fig. 58.
Paraphaniosoma sexvittatum
(Lamb)
, ơ hypopygium, lateral (a) and ventral (b). Scale bar = 0.2 mm.
Fig. 59.
Paraphaniosoma sexvittatum
(Lamb)
: (a, b) ^postabdomen, lateral (a) and ventral (b), scale bar = 0.15 mm; (c–e) spermatheca, lateral (c), oblique (d), anterior (e), scale bar = 0.04 mm.
Wing: Hyaline with pale brown veins; R
2+3
somewhat undulating at middle, R
4+5
and M
1+2
parallel and on costal margin separated by a distance equal to half distance between R
4+5
and M
1+2
; crossveins and vein between discal and basal cell translucent pale yellow, distance between crossveins equal to 1.2× length of posterior crossvein. Haltere yellow with paler knob.
Legs: Yellow and pale brown setulose, hind trochanter normal, claws and pulvilli normal, mid tibia with strong ventral seta at apex. I cannot make out any row of short spines on the top of the front femora as described by
Lamb (1914)
.
Abdomen
:
tg
dark brown, dull with brown dusting,
tg
5 with dorsal elongated quadrate brown spots, otherwise yellow; setulae brown to black about half length of
tg
.
Postabdomen:
tg
6 narrow and brown,
cerc
very small, narrow and pale, pregenital
st
broad with deep excavation fringed with dense long pale setulae,
surs
visible in this space as 2 short black sinuous projections.
Female
.
As male, but
tg
6–8 each with 2 brown almost triangular spots narrowly separated at middle. Postabdomen:
tg
7 complete and
st
7 thinly sclerotized;
tg
8 in
two small lateral sclerites;
st
8 larger than
tg
8 and microtrichose;
hypr
distinct, trapezoidal and of similar size to small
cerc
, both structures with fine setulae.
Length: ơ and ^body
1.5 mm
, wing
1.5 mm
.
Type material examined:
SEYCHELLES
: ơ (
holotype
) “Mahé 08-9, Seychelles Exp. /
Prof. J.S. Gardiner
1914-537 /
A. sexvittata
Lamb
[handwritten] / Type H.T.” [on a red bordered label] (
BMNH
); 3^(
paratypes
)
same data (1^BMNH,
2^CUMZ
). Note: The
holotype
is in a reasonable condition: the pin damages only a part of the right half of the thorax. It has “spec 120” written on the mount
.
Other material examined:
MAURITIUS
: 1ơ Wolmar,
1–2 km
S, coast roadside,
1.vi.2000
, J.W. Ismay (OXUM).
SEYCHELLES
: 1^Aldabra, West I., at light, nr settlement,
30–31.i.1968
, B. Cogan &A. Hutson (NHML); 3ơ 3^Aldabra, West I., at light, nr settlement,
21–31.iii.1968
, B. Cogan & A. Hutson (NHML); 1^Seychelles, North I.,
Calophyllum
(
Clusiaceae
) woodland,
30.vii.2000
, Malaise trap, J. Gerlach (NMWC). Distribution: Mauritius, Seychelles.
Genus
Tethysimyia
gen. n.
Type
species:
Aphaniosoma deemingi
Ebejer, 1996
, here designated.
Etymology: From the Greek name
Tethys
(the sea goddess in mythology) and
myia
(fly), denoting the affinity of this genus with seashore habitats.
Diagnosis: Very small pale flies with rather large round head or head higher than long, very broad gena, well-developed, but narrow facial carina not reaching buccal margin, thus lower part of face between anterior eye margins flat, more or less square and carina therefore less conspicuous than in
Krifomyia
; recessed antenna, but not in deep fossa; chaetotaxy generally reduced and fine, 2 very short
orb
set high on
fr
, 1
dc
, scutal setulae in 4–10 rows between
dc
lines, absent
pra
and
sa
setae, but
post ia
,
pa
and katepisternal present even though short; R 4+5 and M 1+2 slightly convergent; male postabdomen exceptionally small with dorsally narrow, complete epandrium; female with poorly sclerotized
s
, pigmented or unpigmented.
Description:
Head
: More or less round and rather large in proportion to thorax,
fr
broad and moderately convex and protruding in front of eye margin, eye round or only slightly oval, gena broad, at least half height of eye, finely setulose,
ocp
concave though not quite as much as in
Aphaniosoma
, face poorly sclerotized with distinct carina in upper half between antennae, antennae small with third segment rounded, arista 2-segmented, about twice as long as rest of antenna, thickened at base, but rapidly becoming thinner, mouthparts small, palp minute oval and finely setulose, labella not elongated, setulae along buccal margin, including those at vibrissal corner, short and fine. Chaetotaxy: 0–3 very short
orb
, 1
vti
and 1
vte
both short,
pvt
minute or absent.
Thorax
: Rather rounded, not elongated,
scut
of normal shape. Chaetotaxy: 1
pprn
, 1
posthu
,
ihu
present or absent, 2
ntpl
, 1
dc
, scutal setulae very fine and pale in 4–8 rows between
dc
lines,
pra
and
sa
absent, 1
post ia
, 1
pa
, 1 anepisternal, 1 katepisternal, anepisternal and katepisternal setulae scanty and extremely fine or minute,
scut
with usual 4 marginals.
Wing: Hyaline, relatively short and broad, veins very pale yellow,
hu
break present, subcosta merges with R
1
before latter joins costa, no erect spinose setulae on dorsal aspect of costa, R
4+5
and M
1+2
slightly convergent towards apex. Haltere short, pale with pale knob.
Legs: Slender, femora not dilated, segments of all legs pale and finely setulose, mid tibia with apicoventral seta longer than diameter of tibia at apex, hind metatarsus sometimes dilated, hind trochanter normal.
Abdomen
: More or less oval and slightly dorsoventrally compressed, 6 segments in male and
7 in
female,
tg
with fine setulae,
st
poorly sclerotized.
Postabdomen:Atypical for
Aphaniosominae
and closer to that of
Krifomyia
, with reduced modification of hypopygial structures, which are simple and partially within small
ep
;
ep
distinct from
tg
6 and
surs
fused to it, apparently formed of extension of inferior margin.
Distribution: Coasts and islands of the
Gulf
of
Mexico
,
Red Sea
(
Fig. 70
), Indian and Pacific oceans.
Ecology: Probably associated with saline marshes and mangroves in coastal localities, in hot, tropical and subtropical climates.