Dolichopodidae) from Indian Ocean islands
Igor Ya. GRICHANOV
Grichanov, I.Ya. Eight new species of the genus
Mascaromyia Bickel (Diptera: Dolichopodidae) from
Indian Ocean islands
8 new and 2 known species of the genus Mascaromyia
are described from Mauritius and Chagos Archipelago.
Catalogue and a key to known species of Mascaromyia
are given.
I.Ya. Grichanov, All-Russian Institute of Plant Protection,
Podbelskogo 3, St.Petersburg-Pushkin, 189620, Russia.
Key words: Diptera, Dolichopodidae, Mascaromyia, Chagos
Archipelago, Mauritius.
Introduction
The genus Mascaromyia was established by Bickel (1994) for 15
species from the western Indian Ocean Seychelles and Mascarene
archipelagos, previously referred to Sciapus by Dyte & Smith (1980).
Psilopus parallela Macquart and Sciopus guerini Parent regarded by
Bickel (1994) as Mascaromyia should be referred to a new genus
(Grichanov, in press), for their having anterior preapical seta on
middle and hind femora (Parent, 1935), and some other remarkable
attributes. The other listed species as well as newly described
species are similar to generic diagnosis of Mascaromyia (Bickel, 1994)
except the following corrections. Proclinate vertical setae sometimes
absent in males; antennae yellow or black; 4-5 dc present; lateral
scutellar setae microscopic or absent; cerci extremely modified,
usually with two long ventral projections. Lamb (1922) noted that
females of many species included now in Mascaromyia are so extremely
close as to be almost inseparable. Most of the species described and
recorded below completely lacked diagnostic specific
characters, and identification of females is not possible as many
species have identical locality data.
Holotypes and paratypes are conserved in the Natural History Museum
(London).
List of known species of Mascaromyia
Mascaromyia, Bickel, 1994:100. Type species Psilopus pollicifer
Lamb, 1922:375, by designation of Bickel, 1994.
albitarsis Parent, 1935:83 (Sciopus) - Mauritius.
amplicaudata Lamb, 1922:378 (Psilopus) - Seychelles.
babichae sp.n. - Mauritius.
bickeli sp.n. - Mauritius.
desjardsini Macquart, 1842:175 (Psilopus); Parent, 1932a: 874 (re-
description) - Mauritius.
duplicata Parent, 1932b:230 (Sciopus) - Reunion.
dytei sp.n. - Mauritius.
frolovi sp.n. - Mauritius.
grandicaudata Lamb, 1922:378 (Psilopus) - Seychelles.
hutsoni sp.n. - Mauritius.
indistincta Lamb, 1922:376 (Psilopus) - Seychelles.
kalinkini sp.n. - Mauritius.
leptogaster Thomson, 1869:510 (Psilopus); Parent, 1935:86
(redescription) - Mauritius.
librativertex Lamb, 1922:374 (Psilopus) - Seychelles, Mauritius
(!), Chagos Archipelago (!).
makhotkini sp.n. - Mauritius.
magnicaudata Lamb, 1922:377 (Psilopus) - Seychelles.
mauritiensis Parent, 1939:270 (Sciopus) - Mauritius.
pollicifer Lamb, 1922:375 (Psilopus) - Seychelles.
rufiventris Macquart, 1842:174 (Psilopus); Parent, 1935: 89 (re-
description) - Mauritius.
shabuninae sp.n. - Mauritius.
vagabunda Lamb in Bezzi &
Lamb, 1925:546 (Psilopus) - Rodriguez.
Key to known species of Mascaromyia
Males
1. Fore femora with 2 - 5 thorns or spines beneath..................2
- Fore femora without long bristles................................5
2. Fore femora with 2 fine ventral thorns at the base, middle femora
bare.............................................................3
- Fore femora with a row of 5 conspicuous sloping black bristles
beneath on the basal two-thirds..................................4
3. Last tarsomere of fore legs dilated and twisted, and carries a
small side process like a thumb.................M. pollicifer Lamb
- Last tarsomere absolutely simple and undifferentiated............
M. indistincta Lamb
4. Scape and pedicel dark; femora with regular bristles below;
hypopygium less pedicillate...................M. magnicaudata Lamb
- Scape and pedicel orange; fore femora with very irregular rows of
variously sized bristly hairs; middle femora is devoid of the row of
bristles; hypopygium more pedicillate........M. grandicaudata Lamb
5. Thorax including mesonotum and abdomen mostly yellow.............6
- At most pleurae partly orange...................................10
6. Middle femora with 5 strong anterior bristles..M. amplicaudata Lamb
- Middle femora bare...............................................7
7. Vein M2 and apical part of M3+4 absent without fold or indication
on membrane.......................................M. bickeli sp.n.
- Wing venation undistorted........................................8
8. Fore basitarsomere shorter than fore tibia.......M. babichae sp.n.
- Fore basitarsomere 1 and 1/3 times as long as fore tibia.........9
9. Legs yellow; fore basitarsomere as long as second and third
tarsomeres together..............................M. vagabunda Lamb
- Hind legs mostly brown, hind tibiae white in basal third; fore
basitarsomere thrice as long as the rest.......M. makhotkini sp.n.
10. Legs yellow, simple, middle coxae black.......M. duplicata Parent
- All the coxae yellow; if middle and hind coxae brownish, then
femora or tibiae partly brown or some tarsomeres modified
(enlarged, shortened, thin and long, or white).................11
11. Fore basitarsomere long and thin, more than twice as long as rest
tarsomeres.....................................................12
- Fore basitarsomere nearly as long as rest tarsomeres; posterior
border of wing in apical half often foggy...M. librativertex Lamb
12. Face nearly as wide as first flagellomere......................13
- Eyes touching in the middle of face............................14
13. Last tarsomere of fore tarsi strongly enlarged, black............
M. shabuninae sp.n
- Last tarsomere simple, short......................M. hutsoni sp.n.
14. Hind tarsi white..............................M. albitarsis Parent
- Hind tarsi dark-brown...........................................15
15. Antennae yellow, legs yellow, tarsi brownish........M. dytei sp.n.
- Antennae black, hind femora progressively brown towards apex, hind
tibiae brown....................................................16
16. Fore tarsi white, first tarsomere thrice as long as the rest......
M. kalinkini sp.n.
- Fore tarsi dark, first tarsomere twice as long as rest tarsomeres.
M. frolovi sp.n.
Females
1. At least middle coxae black-brown..........M. desjardsini Macquart,
M. mauritiensis Parent, M. duplicata Parent, (?) M. frolovi sp.n.
- All the coxae yellow..............................................2
2. Thorax including mesonotum and abdomen mostly yellow...............
M. amplicaudata Lamb, M. vagabunda Lamb, M. babichae sp.n., M.
bickeli sp.n., M. makhotkini sp.n.
- At most pleurae orange............................................3
3. Fore femora bare or only with 1 - 3 fine ventral setae.............
M. albitarsis Parent, M. rufiventris Macquart, (?) M. kalinkini sp.n.
- Fore femora with 4 - 5 strong ventral spines.....M. librativertex
Lamb, M. pollicifer Lamb, M. indistincta Lamb, M. magnicaudata
Lamb, M. grandicaudata Lamb.
Descriptions and new records
Mascaromyia bickeli sp.n. (Fig. 1)
Holotype. Male, Mauritius: Macchabee Forest, 2.VI.1971 (A.M.
Hutson), B.M.1971-346. Paratype. Male, the same label.
Description. Frons metallic blue-green. Small front vertical bristle
bends forward, postvertical one is just at the angle of eye. Eyes
joined in middle fifth of face. Face bronze-green, grey pollinose.
Epistome as a small triangle with height/base ratioÿ1 ÿ01:2; clypeus as a
small triangle with height/base ratioÿ1 ÿ03:7. Proboscis very short,
orange-brown, covered with small hairs, palpi brown, with long black
bristle and short hairs. Antennae yellow, slightly longer than height
of head. Pedicel swollen, with a group of short bristles. First
flagellomere somewhat darker, longer than its height at base,
pubescent, subtriangle, with thin sharp apex. Arista basodorsal,
scarcely haired. Length ratio of scape to pedicel to first
flagellomere to arista - 4:5:6:45.
Mesonotum and pleura yellow-orange, hind part of mesonotum and
scutellum brilliantly shining blue. Four dorsocentral bristles with a
few hairs in front of them; acrostichals absent. Scutellum with two
strong bristles.
Legs yellow. Fore coxae from the front with yellow hairs, three
yellow apical bristles of various length and ending in a long thin
yellow thorn. Middle coxae from the front with a few yellow apical
hairs and with two fine dark bristles. Hind coxae with one long dark
external bristle. Legs simple, without strong or long bristles. Middle
tibia with a posterodorsal bristle. Middle and hind tibiae with a few
very short apical bristles. Fore basitarsomere thin and long, with a
regular ventral pectination on apical half. Second to fourth articles
of fore tarsi shortened. Length ratio of fore coxa to femora to tibia
to tarsus (segments from first to fifth) - 2.2 : 2.7 : 3.1 : 4.3 : 0.6
: 0.6 : 0.3 : 0.3. Length ratio of middle coxa to femora to tibia to
tarsus (segments from first to fifth) - 1.3 : 3.4 : 5.7 : 3.4 : 1.0 :
0.9 : 0.5 : 0.3. Length ratio of hind coxa to femora to tibia to
tarsus (segments from first to fifth) - 0.9 : 4.9 : 6.8 : 2.0 : 1.6 :
0.9 : 0.5 : 0.3.
Wings hyaline, veins brown. R4+5 and M1 gently curved to each other
in apical fifth. Ratio of parts of costa between R2+3 and R4+5 to
those between R4+5 and M1 - 1.7 : 0.4. M1 without any strong
curvature; M2 presents as a fine fold on membrane; crossvein m-cu
straight. Apical part of M3+4 reduced without indication on membrane,
so forming united vein with m-cu. Anal vein and lobe reduced. Anal
angle absent. Squamae yellow, with brown edging and golden bristles.
Halteres yellow.
Abdomen yellow-brown: first segment yellow, second and third -
mostly yellow, fourth - mostly brown, fifth and sixth - brown with
metallic green reflection; unmodified segments together thrice as long
as mesonotum. 1st-6th abdominal tergits and sternits well developed.
7th segment brownish, 1.5 times as long as 6th segment and as
epandrium. Hypopygium brownish, with short hairs. Cercus yellow,
dorsally densely setose, look like boomerang with crescent-shaped
baso-ventral projection and long apico-ventral appendix, ending in
three spatulate bristles. Surstylus tooth-shaped, with a long bristle
in the middle of distal edge.
Female unknown.
Length: body 3.2 mm; body with antennae 3.9 mm; wing-length 2.4 -
2.6 mm; wing-width 0.7 - 0.8 mm.
Distribution: Mauritius.
Etymology. The species named in honour of the Australian
dipterologist Dr. Daniel J. Bickel.
Diagnosis. Males of M. bickeli can be easily separated from other
species by simple legs (only fore basitarsomere thin and long, with a
regular ventral pectination on apical half), mostly yellow body and
modified wing venation, unusual in Chrysosomatinae. M2 presents as a
fine fold on membrane; apical part of M3+4 reduced without indication
on membrane, so forming united
vein with m-cu.
Mascaromyia makhotkini sp.n. (Fig. 2)
Holotype. Male, Mauritius: Macchabee Forest, 2.VI.1971 (A.M.
Hutson), B.M.1971-346.
Description. Frons metallic blue-green, with violet reflection in
the middle, slightly grey pollinose. Strong front vertical bristle
bends forward, postvertical one is just at the angle of eye. Eyes
joined in middle half of face. Face bronze-black, grey pollinose.
Epistome as a small triangle with height/base ratioÿ1 ÿ02:1; clypeus
almost invisible. Palpi and proboscis short, orange, covered with
small hairs, palpi narrow, with long brown apical bristle. Antennae
orange, slightly longer than height of head. Pedicel somewhat swollen.
First flagellomere brown, longer than its height at base, densely
pubescent, subtriangle, with thin sharp apex. Arista basodorsal,
scarcely haired, arising from small mound. Length ratio of scape to
pedicel to first flagellomere to arista - 5:5:8:50.
Mesonotum and pleura yellow-orange. Area between dorsocentrals, hind
part of mesonotum and scutellum brilliantly shining blue-green. Four
dorsocentral bristles with a few hairs in front of them; microscopic
acrostichals in two rows. Scutellum with two strong bristles.
Legs mostly whitish-yellow. Hind femora except base and hind tibia
except apex and basal third brown. Fore coxae from the front with
yellow hairs, three dark apical bristles of various length and ending
in a long thin yellow thorn. Middle coxae from the front with a few
yellow apical hairs and with two fine dark bristles. Hind coxae with
one dark external bristle. Fore, middle and hind femora with 1-2
preapical ventral hairs. Middle tibia with a posterodorsal bristle.
Middle and hind tibiae with a few very short apical setae. Fore
basitarsomere thin and long, without ventral pectination. Second to
fourth articles of fore tarsi shortened, dark-yellow. Length ratio of
fore coxa to femora to tibia to tarsus (segments from first to fifth)
- 1.5 : 2.9 : 3.2 : 3.8 : 0.9 : 0.5 : 0.3 : 0.3. Length ratio of
middle coxa to femora to tibia to tarsus (segments first and second) -
1.5 : 3.7 : 5.3 : 4.5 : 1.3. Length ratio of hind coxa to femora to
tibia to basitarsomere - 1.3 : 5.2 : 7.5 : 2.3.
Wings hyaline, veins brown. R4+5 and M1 slightly converged, almost
parallel at apex. Ratio of parts of costa between R2+3 and R4+5 to
those between R4+5 and M1 - 2.4 : 0.5. M1 slightly recurved basad,
with rounded right angle bend; M2 straight; crossvein m-cu nearly
straight. Ratio of crossvein m-cu to apical part of M1+2 (fork-handle)
to apical part of M3+4 - 1.6 : 3.9 : 1.8. Anal vein and lobe reduced.
Anal angle absent. Squamae yellow, with brown edging and yellow
bristles. Halteres dark-yellow.
Abdomen yellow-brown: first segment yellow, second, third and fourth
- mostly yellow, fifth and sixth - black-brown with metallic green
reflection; unmodified segments together 2.3 times as long as
mesonotum. 1st-6th abdominal tergits and sternits well developed. 7th
segment and hypopygium yellow-brown, with short hairs. Cercus dorsally
densely setose, with long thin baso-ventral projection and long thin
ventral appendix in the middle, ending in three spatulate bristles.
Surstylus bidentate, with short setae.
Female unknown.
Length: body 3.2 mm; body with antennae 4.0 mm; wing-length 2.9
mm; wing-width 0.9 mm.
Distribution: Mauritius.
Etymology. The species named after the Russian entomologist Dr. A.G.
Makhotkin.
Diagnosis. Male of M. makhotkini can be separated from other
species with bare femora by the following combination of attributes:
thorax including mesonotum and abdomen mostly yellow, wing venation
undistorted, fore basitarsomere 1 and 1/3 times as long as fore tibia
and thrice as long as the rest, hind legs mostly brown, hind tibiae
white in basal third.
Mascaromyia babichae sp.n. (Fig. 3)
Holotype. Male, Mauritius: Trou aux Cerfs, 15.VI.1971 (A.M.
Hutson), B.M.1971-346.
Description. Frons metallic blue-green, with violet reflection in
the middle. Front vertical bristle bends forward, postvertical one is
positioned as a linear continuation of the postocular setae row. Eyes
joined in middle half of face. Face black, grey pollinose. Epistome
and clypeus as small triangles. Palpi and proboscis very short,
orange, covered with small hairs, palpi also with black bristle.
Antennae orange, longer than height of head. Pedicel somewhat swollen.
First flagellomere yellow-brown, as long as heigh at base,
subtriangle, with thin sharp apex, pubescent. Arista dorsal, scarcely
haired, arising from small mound. Length ratio of scape to pedicel to
first flagellomere to arista - 4:5:5:50.
Mesonotum and pleura orange. Area between dorsocentrals, hind part
of mesonotum and scutellum brilliantly shining blue. Four dorsocentral
bristles with a few microscopic hairs in front of them; acrostichals
absent. Scutellum with two strong bristles and two very short hairs
from the outside.
Legs yellow. Fore coxae from the front with yellow and dark hairs,
1-3 dark apical bristles of various length and ending in a long thin
yellow seta. Middle coxae from the front with a few yellow apical
hairs and with two fine dark bristles. Hind coxae with one long dark
external bristle. Fore and middle femora with a long fine basoventral
hair. Fore legs simple. Length ratio of fore coxa to femora to tibia
to tarsus (segments from first to fifth) - 1.9 : 2.6 : 2.6 : 2.1 : 0.7
: 0.5 : 0.3 : 0.3. Middle tibia with one anterodorsal, one
posterodorsal, three or four apical bristles. Length ratio of middle
coxa to femora to tibia to tarsus (segments from first to fifth), 1.7
: 4.3 : 3.4 : 1.7 : 0.7 : 0.5 : Length ratio of middle coxa to femora
to tibia to tarsus (segments first and fifth) - 1.3 : 3.2 : 4.1 : 2.3
: 0.9 : 0.7 : 0.4 : 0.4. Hind tibiae with a row of a few short dorsal
bristles and with a crown of a few short apical bristles. Length ratio
of hind coxa to femora to tibia to tarsus (segments from first to
fifth) - 0.9 : 4.1 : 5.3 : 1.3 : 1.2 : 0.7 : 0.5 : 0.3.
Wings hyaline, veins brown. R4+5 and M1 slightly converged. Ratio of
parts of costa between R2+3 and R4+5 to those between R4+5 and M1 -
2.4 : 0.4. M1 with rounded right angle bend; M2 straight; crossvein
m-cu nearly straight. Ratio of crossvein m-cu to apical part of M1+2
(fork-handle) to apical part of M3+4 - 1.3 : 3.2 : 1.6. Anal vein and
lobe reduced. Anal angle absent. Squamae yellow, with brown edging and
golden bristles. Halteres dark-yellow.
Abdomen yellow-brown: first and second segments yellow, third and
fourth - mostly yellow, fifth and sixth - mostly brown with metallic
green reflection; unmodified segments together twice as long as
mesonotum. 7th segment and hypopygium yellow-brown, with short hairs.
Cercus with long thin baso-ventral projection and long thin
apico-ventral appendix, ending in three spatulate bristles. Surstylus
bidentate and mitten-like, with 1 long and few short setae.
Female unknown.
Length: body 2.9 mm; body with antennae 3.7 mm; wing-length 2.4
mm; wing-width 0.8 mm.
Distribution: Mauritius.
Etymology. The species named after the Russian zoologist Mrs. N.V.
Babich.
Diagnosis. Male of M. babichae is placed within the group of species
with thorax including mesonotum and abdomen mostly yellow, and can be
distinguished from other species by simple legs (fore basitarsomere
shorter than fore tibia) and
wing venation.
Mascaromyia librativertex (Lamb) (Fig. 4)
Material examined: 3 males, Mauritius: La Pouce, 10.VI.1971 (A.M.
Hutson), B.M.1971-346; 7 males, Mauritius: Curepipe, 3.VI.1971 (A.M.
Hutson), B.M.1971-346; female, Chagos Archipelago: Diego Garcia, East
Point, 6.V.1971 / A.M. Hutson, B.M. 1971-346; 2 males & 7 females,
Chagos Archipelago: Diego Garcia, Eclipse Point, 26.III, 1 &
19.IV.1971 / A.M. Hutson, B.M. 1971-346; 3 males & 3 females, Chagos
Archipelago: Diego Garcia, Eclipse Point, 29.III.1971 / A.M. Hutson,
B.M. 1971-346 / dried inland marsh; 1 female, Chagos Archipelago:
Diego Garcia, Simpson's Point, 30.III.1971 / A.M. Hutson, B.M.
1971-346; 1 female, Chagos Archipelago: Diego Garcia, Pointe Marianne,
17.IV.1971 / A.M. Hutson, B.M. 1971-346; 1 female, Chagos Archipelago:
Diego Garcia, Minni Minni, 14.IV.1971 / A.M. Hutson, B.M. 1971-346 /
At light; 1 male & 2 females, Chagos Archipelago: Diego Garcia, Camp
Marcel, 6 & 10.VI.1971 / A.M. Hutson, B.M. 1971-346 / open cocconut
grove / at light.
Diagnosis. M. librativertex is placed within the group of species
with bare femora and dark body and can be separated by simple legs
except fifth tarsomere, which is slightly enlarged on fore legs; fore
basitarsomere nearly as long as rest tarsomeres; posterior border of
wing in apical half usually foggy. Cercus with long thin baso-ventral
projection, bearing pedunculate short seta in the middle and long seta
on the apex. Apico-ventral appendix of cercus short, bidactyl, with
simple bristles. Surstylus tooth-shaped, with two strong setae.
Females are indistinctive from Lamb's descriptions of other species. I
list them here because M. librativertex is the only species
representative of Mascaromyia on Chagos Archipelago.
Distribution: Seychelles, Mauritius (!), Chagos Archipelago (!).
Mascaromyia shabuninae sp.n. (Fig. 5)
Holotype. Male, Mauritius: Le mares, 8.VI.1971 (A.M. Hutson),
B.M.1971-346. Paratype. Male, Mauritius: Periere Reserve, 14.VI.1871
(A.M. Hutson), B.M.1971-346.
Description. Frons metallic blue-green, slightly grey pollinose.
Front vertical bristle bends forward, postvertical one is positioned
as a linear continuation of the postocular setae row. Face
silvery-white, pollinose, very narrow, 7 times as high as wide in the
middle and nearly as wide as first flagellomere. Palpi and proboscis
short, black-brown, densely haired, palpi also with a small black
bristle. Antennae black, shorter than height of head. First
flagellomere nearly as long as heigh at base, triangle, with rounded
apex, pubescent. Arista dorsal, microscopically haired. Length ratio
of scape to pedicel to first flagellomere to arista - 4:4:6:27.
Mesonotum metallic green, with blue reflection, pleura bronze-green,
grey pollinose. Five dorsocentral bristles with 3d and 4th bristles
somewhat smaller, and with a few hairs in front of them; acrostichals
absent. Scutellum with two strong bristles.
Legs yellow, middle and hind coxae and apical segments of tarsi
partly brown. Fore coxae from the front with yellow hairs, two black
apical bristles and ending in a long thin yellow thorn sharply hooked
at the end. Middle coxae from the front with two long yellow hairs and
with a regular dense tuft of yellow hairs at the tip, that have the
appearence of a sea anemone. Hind coxae with one long black external
bristle. Legs thin, without strong or long setae. Fore basitarsomere
thin and long, with a regular distant ventral pectination on apical
half and shallow preapical excavation; fifth tarsomere strongly
enlarged and flattened, not dilated, twice as long as wide, black with
silvery reflection. Length ratio of fore coxa to femora to tibia to
tarsus (segments from first to fifth) - 2.0 : 2.9 : 3.1 : 4.5 : 0.8 :
1.0 : 0.3 : 0.7. Middle tibia with one anterodorsal; fifth tarsomere
slightly flattened. Length ratio of middle coxa to femora to tibia to
tarsus (segments first and fifth) - 1.3 : 3.6 : 6.7 : 5.3 : 1.3 : 1.0
: 0.5 : 0.4. Hind tibiae with two very short dorsal setae. Length
ratio of hind coxa to femora to tibia to tarsus (segments from first
to fifth) - 0.9 : 5.5 : 8.1 : 3.1 : 1.6 : 1.2 : 0.6 : 0.5.
Wings hyaline, veins brown. Ratio of parts of costa between R2+3 and
R4+5 to those between R4+5 and M1 - 2.3 : 0.6. M1 with rounded right
angle bend; M2 straight; crossvein m-cu straight. Ratio of crossvein
m-cu to apical part of M1+2 (fork-handle) to apical part of M3+4 - 1.5
: 3.6 : 1.5. Anal vein and lobe reduced. Anal angle absent. Squamae
dark-yellow, with black edging and brown bristles. Halteres brownish.
Abdomen thin and dark, metallic blue-green, with brownish colour on
tergal overlaps; unmodified segments together thrice as long as
mesonotum. 7th abdominal segment and hypopygium dark-brown, with short
hairs. Cercus bean-shaped, apico-dorsally setose, apicoventrally with
a comb of 5 pedunculate bristles, also with long modified baso-ventral
projection and with two ventral appendices, each ending in two long
spatulate bristles. Surstylus broad, with shallow distal excavation
and with short bristles.
Female unknown.
Length: body 3.4 mm; body with antennae 3.9 mm; wing-length 2.8
mm; wing-width 0.7 mm.
Distribution: Mauritius.
Etymology. The species named after the Russian zoologist Dr. Tanya
Shabunina.
Diagnosis. Males of M. shabuninae can be separated from other
species with metallic green body, bare femora and yellow legs by
undilated last tarsomere of fore tarsi, which is strongly enlarged and
black. Fore basitarsomere long and thin, more than twice as long as
rest tarsomeres. Face nearly
as wide as first flagellomere.
Mascaromyia hutsoni sp.n. (Fig. 6)
Holotype. Male, Mauritius: Curepipe, 3.VI.1971 (A.M. Hutson),
B.M.1971-346. Paratypes. Male, the same label; 3 males, Mauritius:
Periere Reserve, 14.VI.1971 (A.M. Hutson), B.M.1971-346; male,
Mauritius: Black River, 1.VI.1971 (A.M. Hutson), B.M.1971-346 / Top of
George.
Description. Frons metallic blue-green, with violet reflection in
the middle, slightly grey pollinose. Front vertical bristle bends
forward, postvertical one is positioned as a linear continuation of
the postocular setae row. Face silvery-white, grey pollinose, very
narrow, 10 times as high as wide in the middle and somewhat narrower
than first flagellomere. Palpi and proboscis short, black-brown,
densely haired, palpi also with a small black bristle. Antennae black,
as long as height of head. First flagellomere as long as heigh at
base, subtriangle, pubescent. Arista dorsal, microscopically haired.
Length ratio of scape to pedicel to first flagellomere to arista -
5:4:7:37.
Mesonotum metallic blue green, often with violet reflection, pleura
and scutellum bronze-green, grey pollinose. Five dorsocentral bristles
with 3d bristle somewhat smaller, and with a few hairs in front of
them; acrostichals absent. Scutellum with two strong bristles.
Legs yellow, middle and hind coxae and apical segments of tarsi
partly darkened. Fore coxae from the front with yellow and dark hairs,
and ending in a long thin yellow thorn sharply hooked at the end.
Middle coxae from the front with two yellow hairs and with a regular
dense tuft of pale hairs at the tip, from the outside almost bare.
Hind coxae with one long black external bristle. Middle and hind
femora with 1-2 preapical postero-ventral hairs. Fore basitarsomere
thin and long, with a regular distant ventral pectination on apical
half. Length ratio of fore coxa to femora to tibia to tarsus (segments
from first to fifth) - 2.6 : 3.4 : 3.8 : 6.5 : 0.7 : 0.6 : 0.4 : 0.5.
Middle tibia with one anterodorsal, one posterodorsal and two or three
apical bristles. Length ratio of middle coxa to femora to tibia to
tarsus (segments first and fifth) - 1.6 : 3.9 : 7.6 : 6.2 : 1.5 : 1.4
: 0.6 : 0.4. Hind tibiae with two very short dorsal setae, with a few
short apical bristles. Length ratio of hind coxa to femora to tibia to
tarsus (segments from first to fifth) - 1.0 : 6.0 : 9.4 : 3.7 : 2.0 :
1.3 : 0.8 : 0.4.
Wings slightly darkened, veins brown. R4+5 and M1 nearly parallel at
apex. Ratio of parts of costa between R2+3 and R4+5 to those between
R4+5 and M1 - 2.5 : 0.7. M1 with gentle arc to apex, with rounded
right angle bend; M2 straight; crossvein m-cu straight. Ratio of
crossvein m-cu to apical part of M1+2 (fork-handle) to apical part of
M3+4 - 1.5 : 4.6 : 1.7. Anal vein and lobe reduced. Anal angle absent.
Squamae yellow, with black edging and golden-brown bristles. Halteres
dark-yellow.
Abdomen bronze-green, sometimes first and second segments
dark-brown; unmodified segments together more than two times longer
than mesonotum. 7th abdominal segment and hypopygium dark-brown, with
short hairs. Cercus apico-dorsally setose, with long baso-ventral
projection and with broad ventral projection, ending in apico-ventral
comb of bristles and basoventral tridactyl appendix. Surstylus cut at
the apex, carrying a long bristle. Epandrial lobe bidactyl.
Female unknown.
Length: body 3.0 - 3.2 mm; body with antennae 3.7 - 3.9 mm;
wing-length 2.9 - 3.2 mm; wing-width 0.7 - 0.8 mm.
Distribution: Mauritius.
Etymology. The species named after the collector, Dr. A.M. Hutson.
Diagnosis. Male habitus of M. hutsoni is close to M. shabuninae
and the first species can be distinguished by simple tarsi and other
subtle characters.
Mascaromyia albitarsis (Parent) (Fig. 7)
Material examined: male, Mauritius: Black River, 17.VI.1971 (A.M.
Hutson), B.M.1971-346 / Upper mts; male, Mauritius: La Pouce,
10.VI.1971 (A.M. Hutson), B.M.1971-346.
Diagnosis. M. albitarsis is distinctive in having white hind
tarsi. Cercus dorsally setose, with baso-ventral projection and with
S-shaped apico-ventral appendix, bearing a basal comb of 4 setae and 3
apical spatulate bristles. Surstylus rounded, leaf-shaped, with a few
short bristles.
Distribution: Mauritius.
Mascaromyia dytei sp.n. (Fig. 8)
Holotype. Male, Mauritius: Macchabee Forest, 1.VI.1971 (A.M.
Hutson), B.M.1971-346.
Description. Frons metallic bronze-green. No front vertical
bristle, postvertical one is positioned as a linear continuation of
the postocular setae row. Eyes joined in middle third of face. Face
silvery-white, pollinose. Epistome as a narrow triangle with
height/base ratio 14:6. Clypeus as triangle with height/base ratio
13:4. Palpi and proboscis short, orange-brown, densely haired, palpi
also with a strong black bristle. Antennae yellow-orange, slightly
shorter than height of head. First flagellomere as long as heigh at
base, subtriangle, with obtuse apex, slightly pubescent. Arista
dorsal, dark, microscopically haired. Length ratio of scape to pedicel
to first flagellomere to arista - 4:5:6:50.
Mesonotum metallic green, with golden reflection in the middle,
pleura and scutellum bronze-green, metaepimeres brown, grey pollinose.
Five dorsocentral bristles with 3d bristle somewhat smaller, and with
a few hairs in front of them; acrostichals absent. Scutellum with two
strong bristles and two hairs from the outside.
Legs yellow, apical segments of tarsi darkened. Fore coxae from
the front with yellow hairs of various length, and ending in a long
thin dark-yellow thorn. Middle coxae from the front with a few short
yellow hairs, with two fine long bristles and with a regular dense
tuft of pale hairs at the tip, from the outside almost bare. Hind
coxae with one fine external seta. Fore basitarsomere thin and long,
with a regular distant ventral pectination on apical third. Second to
fourth articles of fore tarsi very short. Length ratio of fore coxa to
femora to tibia to tarsus (segments from first to fifth) - 2.3 : 3.2 :
3.6 : 7.0 : 0.15 : 0.15 : 0.15 : 0.2. Length ratio of middle coxa to
femora to tibia to tarsus (segments first and fifth) - 1.5 : 3.9 : 6.7
: 5.7 : 1.4 : 1.0 : 0.5 : 0.4. Length ratio of hind coxa to femora to
tibia to tarsus (segments from first to fifth) - 1.3 : 6.4 : 8.7 : 3.7
: 1.9 : 1.1 : 0.8 : 0.4.
Wings hyaline, veins brown. R4+5 and M1 slightly converged. Ratio
of parts of costa between R2+3 and R4+5 to those between R4+5 and M1 -
2.8 : 0.6. M1 with rounded right angle bend; M2 straight; crossvein
m-cu nearly straight. Ratio of crossvein m-cu to apical part of M1+2
(fork-handle) to apical part of M3+4 - 2.2 : 4.5 : 1.6. Anal vein and
lobe reduced. Anal angle absent. Squamae yellow, with brown edging and
white setae. Halteres yellow.
Abdomen mostly black-brown, with metallic green reflection,
second segment mostly yellow, third and fourth - with yellow lateral
spots; unmodified segments together more than two times longer than
mesonotum. 7th abdominal segment and hypopygium black, with short
hairs. Cercus brownish-yellow, dorsally densely setose, with small
baso-ventral projection, with long pointed apex and with thick
complicated ventral projection. Surstylus oval, with long apical
bristle. Epandrial lobe reduced.
Female unknown.
Length: body 3.9 mm; body with antennae 4.7 mm; wing-length 3.2
mm; wing-width 1.0 mm.
Distribution: Mauritius.
Etymology. The species named in honour of the English
dipterologist Dr. C.E. Dyte.
Diagnosis. Male of M. dytei can be separated from other species
with bare femora by the following combination of attributes: eyes
touching in the middle of face, antennae yellow, legs including coxae
yellow, tarsi brownish, basitarsomere long and thin, ten times as long
as rest tarsomeres, abdomen partly
orange.
Mascaromyia kalinkini sp.n. (Fig. 9)
Holotype. Male, Mauritius: Macchabee Forest, 1.VI.1971 (A.M.
Hutson), B.M.1971-346. Paratypes. 21 males with the same label as
holotype but with catching dates 1, 2 & 8.VI.1971; 1 male, Mauritius:
La Pouce, 10.VI.1971 (A.M. Hutson), B.M.1971-346. 7 males, Mauritius:
Curepipe, 3.VI.1971 (A.M. Hutson), B.M.1971-346. 1 male, Mauritius:
Bel Ombre, 18.VI.1971 (A.M. Hutson), B.M.1971-346. 2 males, Mauritius:
Black River, 17.VI.1971 (A.M. Hutson), B.M.1971-346. 1 male,
Mauritius: Trou aux Cerfs, 15.VI.1971 (A.M. Hutson), B.M.1971-346.
Description. Frons metallic bronze-green. Small front vertical
bristle bends forward, short postvertical one is positioned as a
linear continuation of the postocular setae row. Eyes practically
joined in the middle of face. Face silvery-white, pollinose, presents
as two narrow triangles with very sharp apices. Palpi and proboscis
short, orange-brown, covered with small pale hairs, palpi also with a
black bristle. Antennae black, slightly shorter than height of head.
First flagellomere slightly longer than height at base, subtriangle,
with sharp apex, pubescent. Arista dorsal, minutely haired. Length
ratio of scape to pedicel to first flagellomere to arista - 5:4:7:45.
Mesonotum metallic green, pleura and scutellum bronze-green, grey
pollinose. All bristles except 1 notopleural and 1 supraalary, greatly
reduced. Five short dorsocentral bristles with a few microscopic hairs
in front of them; acrostichals absent. Scutellum with two strong
bristles and two microscopic hairs from the outside.
Legs mostly yellow, fore coxa, femora in basal half and tarsus
whitish, fore and middle tibia except apex, hind tibia, middle femora
at apex, hind femora except basal third and middle and hind tarsi
brown. Fore coxae from the front with a few yellow apical hairs of
various length, and ending in a long thin yellow thorn sharply hooked
at the end. Middle coxae from the front with two fine yellow hairs,
with a regular dense tuft of pale hairs at the tip, from the outside
bare. Hind coxae with one fine dark external seta. Legs without strong
or long bristles or hairs; middle and hind tibia with a few very short
setae. Fore basitarsomere thin and long, with a regular distant
ventral pectination on apical half. Second to fourth articles of fore
tarsi shortened, white. Length ratio of fore coxa to femora to tibia
to tarsus (segments from first to fifth) - 1.6 : 2.5 : 2.7 : 3.3 : 0.3
: 0.3 : 0.2 : 0.3. Length ratio of middle coxa to femora to tibia to
tarsus (segments first and fifth) - 1.1 : 2.9 : 5.2 : 4.3 : 1.1 : 1.8
: 0.3 : 0.25. Length ratio of hind coxa to femora to tibia to tarsus
(segments from first to fifth) - 0.8 : 4.7 : 6.3 : 2.6 : 1.5 : 1.0 :
0.6 : 0.4.
Wings slightly darkened, veins brown. R4+5 and M1 nearly parallel at
apex. Ratio of parts of costa between R2+3 and R4+5 to those between
R4+5 and M1 - 2.3 : 0.4. M1 with widely rounded right angle bend; M2
straight; crossvein m-cu straight. Ratio of crossvein m-cu to apical
part of M1+2 (fork-handle) to apical part of M3+4 - 1.1 : 3.2 : 1.8.
Anal vein and lobe reduced. Anal angle absent. Squamae yellow, with
brown edging and yellow bristles. Halteres yellow with darkened knob.
Abdomen and hypopygium black-brown, with metallic green
reflection; unmodified segments together nearly thrice as long as
mesonotum. Cercus yellow-brown, evenly setose, with long modified
baso-ventral projection, and with long apico-ventral appendix, bearing
a long basal cheta and two apical spatulate bristles. Surstylus broad,
with sharp dorsal angle.
Female unknown.
Length: body 3.0 - 3.5 mm; body with antennae 3.9 - 4.3 mm;
wing-length 2.6 - 3.0 mm; wing-width 0.5 - 0.7 mm.
Distribution: Mauritius.
Etymology. The species named after the Russian entomologist Dr.
Victor Kalinkin.
Diagnosis. M. kalinkini together with M. frolovi is placed within
the group of species with bare femora and dark body and can be
separated from other species by the following combination of
attributes: face extremly narrow, antennae black, hind femora
progressively brown towards apex, hind tibiae brown, fore tarsi white,
first tarsomere thrice as long
as the rest, hind tarsi dark-brown.
Mascaromyia frolovi sp.n. (Fig. 10)
Holotype. Male, Mauritius: La Pouce, 10.VI.1971 (A.M. Hutson),
B.M.1971-346. Paratypes. 2 males with the same label as holotype; 1
male, Mauritius: Curepipe, 3.VI.1971 (A.M. Hutson), B.M.1971-346; 1
male, Mauritius: Maccharbee Forest, 1.VI.1971 (A.M. Hutson),
B.M.1971-346.
Description. Frons metallic blue-green. No front vertical
bristle, postvertical one is positioned as a linear continuation of
the postocular setae row. Face silvery-white, pollinose, very narrow,
slightly widened under antennae and distad, half as wide as first
flagellomere; Clypeus densely haired with short pale setulae. Palpi
and proboscis very short, orange-brown, covered with small hairs,
palpi also with a black bristle. Antennae black, slightly longer than
height of head. First flagellomere 1.5 times as long as heigh at base,
subtriangle, with rounded apex, pubescent. Arista basodorsal,
distinctly haired. Length ratio of scape to pedicel to first
flagellomere to arista - 7:5:9:55.
Mesonotum metallic green, with blue reflection; pleura and
scutellum bronze-green, grey pollinose. Five dorsocentral bristles
with 1-2 setulae in front of them; acrostichals absent. Scutellum with
two strong bristles and two hairs from the outside.
Legs mostly yellow, middle and hind coxae and apical segments of
tarsi mostly brown, hind femora progressively brownish towards apex
from above in apical two thirds, hind tibia and tarsus brown. Fore
coxae from the front with short yellow hairs and two black apical
bristles and ending in a long thin yellow thorn sharply hooked at the
end. Middle coxae from the front with a few yellow hairs of various
length, with a regular dense tuft of pale hairs at the tip. Hind coxae
with one black external bristle, with several yellow hairs. Fore
basitarsomere thin and long. Second to fourth articles of fore tarsi
shortened. Length ratio of fore coxa to femora to tibia to tarsus
(segments from first to fifth) - 2.5 : 3.7 : 4.1 : 4.7 : 0.5 : 0.4 :
0.3 : 0.3. Middle tibia with one strong anterodorsal and one
posterodorsal bristles in basal third, one dorsal in the middle and
several apical bristles. Length ratio of middle coxa to femora to
tibia to tarsus (segments first and fifth) - 1.9 : 3.3 : 7.0 : 5.0 :
1.6 : 1.2 : 0.7 : 0.6. Hind tibia with two short dorsal setae, with a
crown of a few apical bristles. Length ratio of hind coxa to femora to
tibia to tarsus (segments from first to fifth) - 1.3 : 5.5 : 8.5 : 3.0
: 2.0 : 1.1 : 1.0 : 0.5.
Wings slightly darkened, veins brown. R4+5 and M1 converged but
parallel at apex. Ratio of parts of costa between R2+3 and R4+5 to
those between R4+5 and M1 - 3.4 : 0.4. M1 slightly recurved basad,
with rounded right angle bend; M2 straight; crossvein m-cu straight.
Ratio of crossvein m-cu to apical part of M1+2 (fork-handle) to apical
part of M3+4 - 2.5 : 4.4 : 1.5. Anal vein and lobe reduced. Anal angle
absent. Squamae yellow, with brown edging and light bristles. Halteres
yellow.
Abdomen black-brown, with metallic green reflection; unmodified
segments together more than two times longer than mesonotum.
Hypopygium brown with short hairs. Cercus yellow-brown, dorsally
setose, with sharp apex, with long thin baso-ventral projection, and
with apico-ventral appendix, directed basad and bearing a long basal
cheta, two apical spatulate bristles and back peduncule with a seta.
Surstylus tooth-shaped, with several short bristles. Epandrial lobe
prominent, with three setae.
Female unknown.
Length: body 3.9 - 4.3 mm; body with antennae 4.7 - 5.1 mm;
wing-length 3.3 mm; wing-width 1.0 mm.
Distribution: Mauritius.
Etymology. The species named after the Russian entomologist Dr.
Andrew Frolov.
Diagnosis. M. frolovi together with M. kalinkini is placed within
the group of species with bare femora and dark body and is
distinguished from the last one by bigger size and by the following
attributes: fore tarsi dark, first tarsomere twice as long as the
rest, morphology of hypopygium, chetotaxy of legs and mesonotum.
Acknowledgements
I am sincerely grateful to Dr Brian Pitkin for his kindness in
giving me the opportunity to study the collection of the Natural
History Museum (London). I appreciate the help I have received from
Mrs Galina Grichanova in doing the illustrations.
References
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Parent O. 1932. Sur quelques Dipteres Dolichopodides, la plupart
appartenant a la Collection Oldenberg. Notes et descriptions (Dipt.).
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Parent O. 1935. Dipteres Dolichopodides nouveaux. - Encycl.
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Remark under figures
Figs 1-10. Hypopygium, lateral veiw. 1, M. bickeli sp.n.; 2, M.
makhotkini sp.n.; 3, M. babichae sp.n.; 4, M. librativertex (Lamb); 5,
M. shabuninae sp.n.; 6, M. hutsoni sp.n.; 7, M. albitarsis (Parent);
8, M. dytei sp.n.; 9, M. kalinkini sp.n.; 10, M. frolovi sp.n.