New genera of stiletto flies endemic to Madagascar (Therevidae: Therevinae)
Author
Irwin, Michael E.
A2657AD1-FE26-4065-BBA1-3F6E1FAD9831
Emeritus, University of Illinois, Urbana-Champaign, Illinois, USA. & University of Arizona, Tucson, USA.
meirwin@illinois.edu
Author
Winterton, Shaun L.
37F5AC48-EC3A-47ED-902B-2BD1467CCA72
California State Collection of Arthropods, California Department of Food & Agriculture, Sacramento, California, USA.
wintertonshaun@gmail.com
text
European Journal of Taxonomy
2024
2024-04-19
932
1
1
33
https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2507/11225
journal article
10.5852/ejt.2024.932.2507
2118-9773
11001504
EA652637-A88D-41A7-A586-8D57770B9C0E
Rinhatiana
gen nov.
urn:lsid:zoobank.org:act:
C41C01D5-81EE-46F3-B354-1161454B8A81
Type
species
Rinhatiana latifestuca
gen. et sp. nov.
Diagnosis
Male and female with single row of postocular macrosetae (rarely more); prosternal setae absent medially; two pairs of scutellar macrosetae; setae absent on metanepisternum and posterior surface of mid coxa; wing vein R 1 with setulae along dorsal surface; wing cell m 3 open.
Differential diagnosis
Rinhatiana
gen. nov.
belongs to the subfamily
Therevinae
(characterized by the presence of adpressed, scale-like setae on the femora), but has setulae along wing vein R
1
, a character shared with
Tianarinha
gen. nov.
and the New World therevine genus
Protothereva
Malloch, 1932
. It can be separated from
Tianarinha
by the absence of prosternal setae and two pairs of scutellar setae (in
Tianarinha
prosternal setae are present medially and there is only one pair of scutellar setae). In addition, it is separated from
Schoutedenomyia
by the presence of regular sized macrosetae on the foretibia (relatively small in
Schoutedenomyia
). It is distinguished from
Stenopomyia
and
Stenosathe
by the wavy R
4
vein in the wing (straight or gradually curved in
Stenopomyia
and
Stenosathe
).
Etymology
ʻ
Rinhatiana
ʼ is a combination of the nicknames of two key personnel in
Madagascar
who contributed significantly to the project on the
Diptera
of
Madagascar
. We have the honor of naming this genus after Rasolondalao Harin’Hala Hasinjaka (also known as Rin’ha) and Razafindratsita Vololontiana (also known as Tiana). Rin’ha managed and coordinated the Malaise trapping and sample sorting for the project throughout
Madagascar
, while Tiana managed the administrative aspects of the project within the
Madagascar
Institut pour la Conservation des Ecosystemes Tropicaux (MICET). Gender is female.
Description
Relatively small individuals with sparse vestiture.
HEAD. Higher than long; frons flat, pubescent silver-tan dorsally, silver ventrally, matte black band medially; frons width strongly sexually dimorphic, male frons width at narrowest point narrower than ocellar tubercle width, nearly contiguous in some species, inner margin of female compound eyes subparallel; parafacial without setae; face flat; postocular ridge of male and female with single row of macrosetae along postocular ridge, rarely two distinct rows; occiput pubescence dull silver to gray or brown; gena rounded; antenna subequal to head length, positioned on lower half of head, directed anteriorly; scape relatively short, cylindrical, less than 3× pedicel length; flagellum tapered cone-shaped, subequal to combined length of scape and pedicel, style apical, elongate; palpus slender, mouthparts short.
THORAX. Central depression of prosternum bare, without setae; cervical sclerite lacking macrosetae; scutum covered with filiform setae, often of variable length; pleuron overlain with silver-tan pubescence; metanepisternum with postspiracular setae absent; metakatepisternum with setae absent; femora relatively short, hind femur and tibia distinctly longer and thicker than fore and mid legs; posterior surfaces of mid- and hind coxae without setae, hind coxal knob present; femoral vestiture includes filiform seta admixed with adpressed, lanceolate and scale-like setae; forefemur and midfemur macrosetae absent, hind femur with 0–3 subapical anteroventral macrosetae, posteroventral macrosetae present as subapical series; tibial macrosetae regular sized; scutal chaetotaxy (pairs of macrosetae): notopleural, 3; supra alar, 1 (rarely 2); post alar, 1; dorsocentral, 0–1; scutellar, 2; wing smoky (light infuscate), vein R
1
with setulae present on dorsal surface, R 4 slightly wavy, cell m 3 open, veins M 3 and M 4 separate to margin, wing membrane uniformly covered with microtrichia.
ABDOMEN. Relatively slender, slightly narrowed along length.
TERMINALIA. Epandrium slightly arched, posterolateral corners thickened and pointed; gonocoxites separate medially with posteromedial margins proximal; inner gonocoxal process (igp) present, not articulated; outer gonocoxal processes well-developed; ventral lobe large, elongate and narrow apically; phallus with dorsal apodeme of parameral sheath triangular, separate from gonocoxites laterally; ventral apodeme single lobe, narrow, single sub-triangular lobe; distiphallus narrow, short; female tergite 8 elongate with anteromedial process; sternite 8 posterior margin emarginate posteromedially; female acanthophorite setae as two sets (A1 & A2), A1 setae usually enlarged; spermathecal sac as single lobe with spermathecal ducts originating on main spermathecal sac duct; two spermathecae.
Remarks
Rinhatiana
gen. nov.
is a distinctive genus of diminutive flies likely the sister genus to
Tianarinha
gen. nov.
The presence of setulae along the dorsal surface of wing vein R 1 is known in all
Phycusinae
(except for
Schlingeria
Irwin, 1977
) and in only one genus of
Xestomyzinae
(
Henicomyia
Coquillett, 1898
). They are absent in all known
Agapophytinae
, while in
Therevinae
setulate along R
1
is only found in the South American genus
Protothereva
and some species of the Australian genus
Anabarhynchus
Macquart, 1848
.
Protothereva
is placed in the predominantly New World
Cerocatus
genus group, likely close to
Brachylinga
Irwin & Lyneborg, 1981
, while
Rinhatiana
and
Tianarinha
are placed in the largely Old World
Thereva
genus group, closely related to
Stenopomyia
,
Stenosathe
,
Megapalla
Lyneborg, 2001
and
Schoutedenomyia
.
Webb & Metz (2003)
mentioned that some undescribed species of
Stenopomyia
had R 1 setulae. Those species are described here in the genera
Rinhatiana
and
Tianarinha
. In addition, one previously described species,
Stenopomyia distincta
Lyneborg, 1976
, also has R
1
setulae and is placed in
Rinhatiana
.