Two new species of Thoracochaeta Duda from the Isle of Eivissa (Balearic Islands) (Diptera, Sphaeroceridae)

6 Pages·1994·0.29 MB·

by  Hjorth-Andersen, Miguel Carles-Tolra

Two new species of Thoracochaeta
Duda from the Isle of Ibiza
(Balearic Islands) (Diptera,
Sphaeroceridae)
Miguel CARLES-TOLRÁ
Carles-Tolrá, M., 1994. Two new species 01 Thoracochaeta Duda Irom Ihe Isle 01
SHNB Ibiza (Balearic Island) (Diplera, Sphaeroceridae). BolI. Soco Hist. Nat. Ba/ears, 37:
91-96 ISSN 012-260X. Palma de Mallorca.
@
Two sphaerocerid species new lo science, namely Thoracochaeta erectiseta sp.n.
and Thoracochaeta pa/pebris sp.n., are described Irom Ihe Balearic Islands.
Keywords: Sphaeroceridae, Thoracochaeta, two new species, Ba/earic /s/ands.
DUES NOVES ESPECIES DE THORACOCHAETA DUDA DE L'ILLA D'EIVISSA
Se descriuen dues especies noves per la ciencia d'esferocerids de les Piliüses;
Thoracochaeta erectiseta sp. n. i Thoracochaeta pa/pebris sp. n.
SOCI ETAT O'HISTORIA Para u/es e/au: Sphaeroceridae, Thoracochaeta, dues noves especies, illes
NATURAL DE LES BALEARS Pitiüses.
Miguel CARLES-TOLRÁ: Avda. Príncep d'Astúries 30 atic la. E-08012 Barcelona,
Spain
Recepció del manuscrit, 28-set-93. Revisió acceptada, 12-set-94
Introduction In June 1988 and 1989 the
author had the opportunity of making a
The genus Thoracochaeta Duda travel to the Isle of Ibiza (Balearic
(1918) comprises 9 species in the Islands). During the short stay (only one
palaearctic region (Papp, 1984; Munari, week each year) they were collected as
1989). Species, known as seaweed many diptera as possible (mostly
flies, are associated with decaying acalypterate) Carles-Tolrá. During the
seaweed cast up in the supralittoral study of the specimens of Sphaero
zone (Marshall, 1982; Marshall & ceridae, 2 new species to science were
Norrbom, 1985). found, as well as new and interesting
92 Bol/. Soco Hist. Nat. Ba/ears, 37 (1994)
records to the Isle of Ibiza. The new longer than separation between posterior
species belong to Thoracochaeta Duda ocelli. 3 interfrontal bristles and 1 pair
and are described below. of small anterior bristles in front of
The family Sphaeroceridae and them. Antennae widely separated by the
genus Thoracochaeta are recorded for convex facial knob, and directed late
the first time from the Isle of Ibiza and rally. Arista long, with long pubescence.
from the Balearic lslands respec-tively Eye height!genal height: males=:: 1.8-2.5;
(Carles-Tolrá, 1990a,b,c). temales;:; 1.5-2.0. Chaetotaxy: 20rs, vte,
vti and occi strong, occe short. oc in
serted outside the ocellar triangle and
Thoracochaeta erectiseta sp.n. directed laterally. ors and vte arranged
in a more or less straight line. Postoce
ro General colour brownish to brown. llar minute hairs present. Vibrissae,
Head: interfrontal plate wider than subvibrissal and genal bristle present.
long (wide/length: males", 1.4-1.5; Thorax: 1+ 2dc (two foremost dc
females=:: 1.3-1.6). Interfrontal plate inclinate), ac in 6 rows anteriorly and 4
2
3 4
Fígs. 1-4. Thoracochaeta erectiseta sp.n.: 1) male sternite 5, mid part, 2) right
gonostylus in latera! view, 3) tergite 7 of female in dorsal view, 4)' stemite 7 of female
in ventral view. Scales '" 0.1 mm·.
Figs. 1-4. Thoracochaeta erettiseta sp.n.: 1) estemi! 5 del masele, zona mítja; 2) visió
lateral del gonostil dret; 3) tergit 7 de la femella en visió dorsal; 4) estemi! 7 de la
=
femella en visi6 ventral. Escala 0.1 mm.
M. Car/es-To/rá, Two newspecies of Thoracochaeta .f wm·/biza 93
posteriorly. Prescute-lIar acrostichal posterior spines, posteromedian protube
bristles slíghtly longer than other rance also lacking.
acrostichals, but shorter than dorso Male genitalia: gonostylus (Fig. 2)
central bristles. Prescutellar acrostichal with two long pointed prolongations (1
setulae lacking. Chaetotaxy: 2hu (poste ventral and 1 anterior) forming a right
rior longer), 2np (posterior erect), 1 angle, mid part with some long hairs.
erect prst just aboye anterior notopleu Paramere slightly curved forwards, poin
ral, 1s a, 1p a, 2st (anterior minute). ted.
Scutellum with 2 long scutellar bristles, Female genitalia: tergite 7 (Fig. 3)
basal ones distinctly erect, almost pentagonal, longer than tergite 6, poste
perpendicular to the scutellum, slightly rior margin rounded, with lateral hairs.
inclínate. Tergite 8 divided into 3 parts, mid part
Wing: CS1, just at the confluence reduced, much shorter than wide. Cerci
of humeral and costal veins, with a short, rounded, with short hairs. Sternite
distinct erect long bristle perpendicular 7 (Fig. 4) with posterolateral short hairs,
to the wing plane, very slightly inwards other setae minute. Sternite 8 somewhat
curved. Other bristles of Cs1 distinctly longer than wide, posterior margin
shorter and not perpendicular. Base of rounded with minute hairs. 1+ 2 sperma
wing with a pair of long bristles (dorsal thecae.
one a few longer), but not perpendicular Total body length: males 1.4-1.8
to the wing plane. Cs2 and Cs3 varia mm; females 1.4-2.1 mm.
ble (Cs2 shorter than, equal as or
longer than Cs3). ta-tp/tp: males= 1.5- Type material: Holotype d': Ba
2.1; 1emales= 1.6-2.0. M1 +2 slightly learic Islands, Ibiza, Cala Es Canar,
sinuate. 25.6.1989, on heap 01 decaying Posi
Legs: mid femur with 2 stout donia in the shore, M. Carles-Tolrá leg.
anteropreapical bristles different in Paratypes: 46d'd'and 4299, same da
length and 1 short posteroapical bristle. ta as the holotype; Ibiza, Punta Arabí,
Mid tibia with 3 distinct pairs 01 dorsal 30.6.1988 4d'tj", 28.6.1989 3d'd' 499,
bristles (distal pair much longer and at light, M. Carles-Tolrá leg. Type mate
distinctly upcurved), ventrally with a row rial deposited in the author's collection.
01 short, stout bristles, midventral bristle
absent, ventroapical bristle present. Hind Discussion: the combination 01 3
femur with an anteroventral preapical pairs 01 dorsal bristles on mid tibia and
bristle. Hind tibia with 2 long weak dor lacking 01 posterior spines on sternite 5,
sal hairs and with a distinct short makes Thoracochaeta erectiseta sp.n.
ventroapical bristle. Hind basitarsus with different from all palaearctic congeners.
a short, stout anteroventral apical The other known species lacking poste
bristle. rior spines on sternite 5 is· Th. flaminuta
Abdomen: tergites 2-5 glabrous, Marshall (1982) which occurs in the
with only 2 lateral bristles (posterior nearctic region (U .SA: Florida), but it
longer). Tergite 5 1urthermore with 1-2 has 4 pairs 01 dorsal bristles on mid
pairs 01 very short posterior bristles. tibia. Furthermore, Th. erectiseta differs
Male sternite 5 (Fig. 1) haired, lacking 1rom the other species tor the peculiar
94 Bo/l. Soco Hist. Nat. Balears, 37 (1994)
erect bristles of the wing and scutellum. Wing: Cs1 with long bristles. Cs2
Biology: the specimens were slightly shorter than Cs3. ta-tp/tp: male=
mainly collected· on heap of decaying 1.5; females= 1.6. M1 +2 slightly sinuate.
Posidonia in the shore. A few Legs: mid femur with 2 stout
specimens were collected at light. anteropreapical bristles different in
Distribution: hitherto only known length and 1 short posteroapical bristle.
from the Isle of Ibiza. Mid tibia with 3 distinct pairs of dorsal
Etimology: the specific name bristles (distal pair much longer),
refers to the distinct erect bristles of the ventrally with a row of short, stout
wing and scutellum. bristles, midventral bristle absent,
ventroapical bristle present. Hind femur
with an anteroventral preapical bristle.
Thoracochaeta palpebris sp.n. Hind tibia with 2 long weak dorsal hairs
and with a distinct short ventroapical
General colour brownish to brown. bristle. Hind basitarsus with a short,
Head: interfrontal plate wider than stout anteroventral apical bristle.
long (wide/length: male= 1.6; females= Abdomen: tergites 2-3 glabrous,
1.6-1.7). Interfrontal height longer than with only 2 lateral bristles (posterior
separation between posterior ocelli. 3 longer). Tergites 4-5 furthermore with
interfrontal bristles and 1 pair of small some posterolateral short bristles (very
anterior bristles in front of them. short to minute in the females). Male
Antennae widely separated by the sternite 5 haired, with a peculiar
convex facial knob, and directed late posteromedian comb of 17 spines,
rally. Arista long, with long pubescence. eyelash-shaped (Fig. 5); posteromedian
Eye height/genal height: male= 2.2; protuberance very separed to each
females= 1.6~2.0. Chaetotaxy: 20rs, vte, other and only slightly overpassing the
vti and occi strong, occe short. oc comb of spines; hairs between both
aligned with anterior and posterior ocelli protuberances minute, almost invisible.
and directed laterally. ors and vte arran Male genitalia: gonostylus (Fig. 6)
ged in a more or less straight line. Pos pointed, curved forwards, with a minute
toce llar minute hairs present. Vibrissae, apical tooth, anterior side concave (it
subvibrissal and genal bristle present. seems a spoon), base dilated with an
Thorax: 1+ 2dc (two foremost dc anterior proyection, posterior side with
inclinate), ac in 6 rows anteriorly and 4 some long proximal and minute distal
rows posteriorly. Prescutellar acrostichal hairs.
bristles slightly longer than other Female genitalia: tergite 7 (Fig. 7)
acrostichals, but shorter" than dorso rectangular, concave anteriorly, with a
central bristles. Prescutellar acrostichal curved dark line in the middle, some
setulae lacking. Chaetotaxy: 2hu (poste long posterolateral bristles present.
rior longer), 2np (posterior erect), 1 Tergite 8 divided into 3 parts (1 median
erect prst just above anterior and 2 lateral), mid part oval,
notopleural, 1 sa, 2pa, 2st (anterior desclerotized. Sternite 7 normal-shaped,
minute). Scutellum with 2 long scutellar rectangular, with posterior short hairs.
bristles. Sternite 8 (Fig. 8) wider than long,
M. Carles-Tolrá, Two new species of Thoracochaeta from Ibiza 95
5
6
7 8
Figs. 5-8. Thoracochaeta palpebris sp.n.: 5) posteromedian row of teeth of sternite 5 of
male in ventral view, 6) left gonostylus in lateral view, 7) tergite 7 of female in dorsal
view, 8) sternite 8 of female in ventral view. Scales= 0.1 mm.
Figs. 5-8. Thoracochaeta palpebris sp.n.: 5) línia denticular posteromediana de I'esternit
5 del mascle en visió ventral; 6) gonostil esquerre en visió lateral; 7) tergit 7 de la
femella en visió dorsal; 8) esternit 8 de la femella en visió ventral. Escala = 0.1 mm.
Discussion: Thoracochaeta pa/
convex posteriorly, with 1 pair of long
pebris sp.n. is closely related to Th.
lateral hairs, some minute posterior
mediterranea M unari (1989), both
hairs also present. Cercus short, with 1
species clearly differ in the number of
apical long hair and 2 preapical shorter
acrostichal rows (3-4 in Th. mediterra
ones. 1 +2 spermathecae.
nea) , as well as in male sternite 5 (Th.
Total body length: male 1.9 mm;
medíterranea with a row of only 12
females 1.9-2.1 mm.
spines, posterior proyections closely
each to other ando distinctly overpassing
Type material: Holotype d' : Ba the row of spines, pair of hairs between
learic Islands, Ibiza, Cala Es Canar, posterior proyections very long and very
25.6.1989, on heap of decaying Posido well visible) and gonostylus (much less
nia in the shore, M. Carles-Tolrá leg. angulated in Th. mediterranea).
Paratypes: 2 <:;? <:;? , same data as the
holotype, M. Carles-Tolrá leg. Type ma Biology: the specimens were
terial deposited in the author's col lec collected on heap of decaying Posidonía
tion. in the shore.
.96 BolI. Soco Hist. Nat. Balears,. 37 (1994)
Distribution: hitherto only known · (Dipt) from Spain. Entomologist's
from the Isle of Ibiza. mono Mag., 126: 33-46.
Etimology: from the Latin Carles-Tolrá, M. 1995. Nuevas citas de
"palpebra" meaning "with eyelashes", it dípteros acalípteros para las Islas
refers to the eyelashes-shaped disposi Baleares, junto con una lista prelimi
tion of the spines of sternite 5. nar de 11 familias (Diptera,
Acalyptrata). Boln. Asoc. esp. Ent.,
Acknowledgements 19: (en prensa).
Marshall, SA 1982. A revision of the
I want to express my sincerest nearctic Leptocera (Thoraco-chaeta
thanks to Dr. Lorenzo Munari (Venezia) Duda) (Diptera: Sphaero-ceridae).
for his comments, as well as to Mrs. Can. Ent., 114: 63-78.
Joana Danés for her help on Latin. Marshall, SA & NORRBOM, A.L. 1985.
Thoracochaeta cubita (Diptera:
Sphaeroceridae), a new species of
References seaweed fly from California. Ent.
News, 96(1): 24-26.
Carles-Tolrá, M. 1990a. Catálogo de los Munari, L 1989. A new species of
Sphaeroceridae de España Peninsu Thoracochaeta Duda, 1918 from the
lar e Islas Baleares (Diptera: Isle of Pantelleria (Diptera, Sphaero
Acalyptratae). Ses. Entom. ICHN ceridae). Soco Ven. SC. Nat. Vene
SCL, 6(1989): 213-220. zia, 14(2): 69-71.
Carles-Tolrá, M. 1990b. Contribución al Papp, L. 1984. Family Sphaeroceridae.
estudio de los Diptera, Cyclorrhapha, In Soós, A.: Catalogue of Palaearctic
Acalyptratae (Insecta) de España Diptera. Volume 10. Clusiidae-Chlo
peninsular. Tesis Doctoral. Facultad ropidae: 68-107. Elsevier Sci. Publ.,
de Biología, Barcelona. 621 pp. Amsterdam & Akadémiai Kiadó,
Carles-Tolrá, M. 1990c. New species Budapest.
and records of Sphaeroceridae