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

Bezzi M., Lamb C.G. 1925. Diptera (excluding Nematocera) from the

island of Rodriguez. - Transactions of the Entomological Society of

London 1925, p. 537-573.

Bickel D.J. 1994. The Australian Sciapodinae (Diptera:

Dolichoodidae), with a review of the Oriental and Australasian faunas,

and a world conspectus of the subfamily. - Rec. Austral. Mus., 1994,

Suppl. 21: 1-394.

Dyte C.E. & Smith K.G.V. Family Dolichopodidae. In R.W. Crosskey

(ed.). Catalogue of the Diptera of the Afrotropical Region. Brit. Mus.

(Nat. Hist.), London, p. 443-463.

Lamb C.G. 1922. The Percy Sladen Trust expedition to the Indian

Ocean in 1905, under the leadership of Mr.J.Stanley Gardiner, M.A.

Vol. 7. N VIII. Diptera: Asilidae, Scenopinidae, Dolichopodidae,

Pipunculidae, and Syrphidae. - Transactions of the Linnean Society of

London (2, Zoology), 18, p. 361 - 416.

Parent O. 1932a. Etude sur quelques types de Macquart (Dipteres

Dolichopodides) conserves au Museum National d'Histoire Naturelle de

Paris. - Bull. Mus. Nat. Hist. Paris, 2, 4, p. 872-881.

Parent O. 1932. Sur quelques Dipteres Dolichopodides, la plupart

appartenant a la Collection Oldenberg. Notes et descriptions (Dipt.).

- Stettin. Entomol. Zeit., 93, p. 220-241.

Parent O. 1935. Dipteres Dolichopodides nouveaux. - Encycl.

Entomol. (B) Diptera, 8: 59-96.

Parent O. 1939. Dipteres Dolichopodides de la region ethiopienne.

- Rev. Zool. Bot. Afr., 1939, 32, p. 256-282.

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.