Three endemic Aphaenogaster from the Siculo-Maltese archipelago and the Italian Peninsula: part of a hitherto unrecognized species group from the Maghreb? (Hymenoptera: Formicidae: Myrmicinae)
Author
Alicata, Antonio
Via Passo Gravina 245 / 12, I- 95125, Catania, Italy
antonioalicata@gmail.com
Author
Schifani, Enrico
0000-0003-0684-6229
Section Animal Biology, Department STEBICEF, University of Palermo - Via Archirafi 18, I- 90123, Palermo, Italy
enrsc8@gmail.com
text
Acta Entomologica Musei Nationalis Pragae
2019
Acta. Ent. Mus. Natl. Pragae
2019-01-28
59
1
1
16
http://zoobank.org/0ea032e4-230f-45df-bdeb-6acea88af418
journal article
5794
10.2478/aemnp-2019-0001
904598c4-3a08-4bac-9ef9-ef69dc4fa9d2
1804-6487
4504968
0EA032E4-230F-45DF-BDEB-6ACEA88AF418
Aphaenogaster sicula
Emery, 1908
Published records (excluding bibliographic checklists).
As
Aphaenogaster subterranea
var.
subterraneo-splendida
in
EMERY & FOREL (1879)
(
type
material – examined, see
EMERY 1908
) and as
A. crocea sicula
in
EMERY (1908)
(
type
material –
examined) and
KUTTER (1927)
(material examined).
Material under the name
A. crocea sicula
in
BARONI URBANI (1964)
belongs to
A. subterranea ichnusa
(material examined), those in
BARONI URBANI (1968)
(
material examined) and as
A. sicula
in
SCHEMBRI & COLLINGWOOD (1981)
(material examined) belong to
A. fiorii
stat. nov.
, those in
SCUPOLA (2009)
(material examined) and
LI VIGNI (2014)
(pictures examined) belong to
A. trinacriae
sp. nov.
Material published in
PETROV (2000)
could not be examined, but was most likely misidentified (
KARAMAN 2011
).
Type material examined.
LECTOTYPE
(here designated):
1 ☿
(top specimen of three☿☿ on one pin),
8.XII.1877
/
Mt.Pellegrino
/☿ //
A. crocea
/
sicula
Emery
(handwritten) // Coll. C. Emery / Museo Genova // ANTWEB/
CASENT0904177
// LECTOTYPUS * / des. Alicata &
Schifani 2018
//
Aphaenogaster sicula
det. Alicata &
Schifani 2018
[M. Pellegrino (PA),
Sicily
,
MSNG
].
PARALECTOTYPES
: 2 ☿☿, same as
lectotype
on the same pin as the
lectotype
, plus //
PARALECTOTYPUS
//.
1 ♀
,
A. crocea
/
sicula
Emery
//
8.XII.1877
/ Mt. Pellegrino /
♀
// Coll. C. Emery / Museo Genova //
PARALECTOTYPUS
/ des. Alicata &
Schifani 2018
//
Aphaenogaster sicula
det. Alicata &
Schifani 2018
[M. Pellegrino (PA),
Sicily
,
MSNG
].
3 ☿☿
,
A. crocea sicula Emery
//
8.XII.1877
/
Mt. Pellegrino
/
☿
// Coll. A. Forel // PARALECTOTYPUS / des. Alicata &
Schifani 2018
//
Aphaenogaster sicula
det. Alicata &
Schifani 2018
[M. Pellegrino (PA),
Sicily
,
MHNG
].
Additional material examined.
ITALY
:
SICILY
:
Segesta
(AG), Sicily, Italy, 1927, leg.
H.Kutter
(
KUTTER 1927
) (
MZLS
);
Pendici di M.Altesina, Nicosia (EN), Sicily, Italy,
37°40
′
22.19
″
N
,
14°18
′
38.62
″
E
,
840 m
, meadow,
30.viii.1993
, leg. A. Alicata (
AACI
);
Colle Vampolieri, Acicatena (CT), Sicily, Italy,
37°34
′
21.1
″
N
,
15°09
′
19.4
″
E
,
140 m
,
11.xi.1993
, leg. A. Alicata (
AACI
,
MSNM
);
Lago Arancio, S. Margherita Belice (AG), Sicily, Italy,
37°38
′
43.8
″
N
13°03
′
49.9
″
E
,
185 m
, meadow near the shore,
11.xii.1993
, leg. A. Alicata (
AACI
);
Misilifurmi, Sciacca (AG), Sicily, Italy, meadow,
37°36
′
04.4
″
N
,
13°02
′
44.8
″
E
,
80 m
,
11.xii.1993
, leg. A. Alicata (
AACI
);
Ficuzza (PA), Sicily, Italy,
37°53
′
6.23
″
N
,
13°22
′
41.29
″
E
,
650 m
, meadow,
18.ii.1994
, leg.A.Alicata (
AACI
);
Baida, Scopello (TP), Sicily, Italy,
38°02
′
55.3
″
N
,
12°47
′
46.4
″
E
,
390 m
, meadow,
1.iii.1994
, leg. A.Alicata (
AACI
);
C.da Catuffo, M.Sparagio,Custonaci (TP), Sicily,Italy,
38°02
′
33.2
″
N
,
12°45
′
12.9
″
E
,
340 m
, meadow,
02.iii.1994
, leg.A.Alicata (
AACI
);
P.zo Giacolamaro, M. Sparagio, Custonaci (TP), Sicily, Italy,
38°3
′
18.70
″
N
,
12°44
′
25.08
″
E
,
660 m
, meadow,
02.iii.1994
, leg.A.Alicata (
AACI
);
SS118 Corleone-Marineo km 26 (PA),Sicily, Italy,
37°51
′
08.4
″
N
,
13°18
′
50.7
″
E
,
490 m
, meadow,
19.ii.1994
, leg.A.Alicata (
AACI
);
Gualtieri Sicaminò (ME), Sicily, Italy,
38°9
′
27.26
″
N
,
15°19
′
27.83
″
E
,
285 m
, meadow,
24.xi.1994
, leg. A. Alicata (
AACI
);
Lago di Piana, Piana degli Albanesi (PA), Sicily, Italy,
38°3
′
18.70
″
N
12°44
′
25.08
″
E
,
600 m
, meadow near the shores,
2.iii1994
, leg.A.Alicata (
AACI
);
Pendici di M. Scalpello, Catenanuova (EN), Sicily, Italy,
37°33
′
5.35
″
N
,
14°40
′
54.84
″
E
,
840 m
, meadow,
31.iii.1999
, leg. A. Alicata (
AACI
);
Monte Pellegrino (PA), Sicily, Italy,
38°10
′
22.4
″
N
,
13°21
′
03.5
″
E
,
395 m
,
Pinus
reforestation,
12.iv.2016
, leg. E. Schifani (
ESPI
);
Gole del Drago (PA), Sicily, Italy,
37°51
′
57.1
″
N
,
13°18
′
03.1
″
E
,
470 m
, meadow near a degraded low Mediterranean maquis,
24.iv.2016
, leg. E. Schifani (
ESPI
);
Erice (TP), Sicily, Italy,
38°02
′
24.8
″
N
,
12°35
′
09.2
″
E
,
700 m
, meadow surrounded by
Quercus ilex
forest and
Pinus
reforestation,
04.xi.2016
, leg. E. Schifani (
ESPI
);
Lago di Prizzi (PA), Sicily, Italy,
37°44
′
02.7
″
N
,
13°24
′
28.2
″
E
,
650 m
, meadow,
22.v.2016
, leg. E. Schifani (
ESPI
);
Grotta di S. Teodoro (ME), Sicily, Italy,
38°03
′
00.1
″
N
,
14°35
′
29.8
″
E
,
135 m
, olive crops,
xii.2017
, leg. E. Genduso (
ESPI
).
ITALIAN PENINSULA
:
Platì (RC), Italy,
38°13
′
05.7
″
N
,
16°02
′
54.5
″
E
,
280 m
, meadow,
16.xi.1993
, leg.A.Alicata (
AACI
,
MSNM
);
Africo Nuovo (RC), Italy,
38°2
′
52.42
″
N
,
16°8
′
13.52
″
E
,
20 m
,meadow,
17.xi.1993
, leg.A.Alicata (
AACI
);
F.mara S.Venere,Samo (RC), Italy,
38°4
′
12.57
″
N
,
16°4
′
42.10
″
E
,
80 m
, meadow,
14.iv.1997
, leg. A.Alicata (
AACI
);
P.te Torr.S.Venere,S. Luca (RC), Italy,
38°08
′
42.9
″
N
,
16°04
′
43.8
″
E
,
80 m
, meadow,
20.xi.1993
,
23.i.2003
,leg.A.Alicata (
AACI
,
MSNM
).
Bova (RC), Italy,
37°57
′
51.9
″
N
15°55
′
21.5
″
E
,
380 m
, meadow,
13.xi.2016
, leg. E. Schifani (
ESPI
).
Worker redescription
(
Figs 5, 6, 10
,
14, 15
). Measurements and indices (90 individuals, 14 localities): HL: 1.05 ± 0.04 (0.95–1.15); HW: 0.90 ± 0.05 (0.80–1.00); CI: 85.35 ± 2.30 (79.54–90.69); FW: 0.77 ± 0.04 (0.67–0.85); SL: 1.10 ± 0.04 (1.00–1.20); SI: 122.50 ± 3.43 (115.00–129.41); MW: 0.58 ± 0.03 (0.52–0.65); ML: 1.37 ± 0.06 (1.25 ± 1.50). Whole body ferruginous, yellowish in freshly emerged workers, except for gaster which is dark brown. Head darker, more brownish than mesosoma and legs. Head subrectangular, lateral margins under eyes slightly rounded, posterior margin of head slightly rounded. Anterior margin of clypeus gradually convex, mandibles rounded. Antennae with twelve segments, antennal club with four segments. Promesonotal suture only slightly marked, the two forming almost continuous dorsal profile in lateral view. In lateral view dorsal profile of metanotum is rounded, dorsal profile of propodeum mostly straight, spines variable, often slightly oriented upwards. Sculpture relatively weak and shiny aspect in general. Head finely reticulated with longitudinal striae mostly limited to lateral areas under eyes, sparsely present above eyes and variably on mandibles. Mesepisternum and propodeum reticulated with fine longitudinal striae, pronotum finely imbricate, gaster smooth, petiole and postpetiole finely imbricate to reticulate. Suberect and erect setae sparse all over head, decumbent setae on mandibles, adpressed setae on scapes and adpressed to subdecumbent setae on flagellomeres. Long setae extending down from clypeus. Erect setae all over dorsal surface of mesosoma, petiole and postpetiole, and all over gaster. Mostly adpressed, partly suberect setae on legs, with sparse erect setae on coxae and femora.
Male description
(
Figs 22, 23, 27
,
31, 32
). Measurements and indices (5 individuals, 1 locality): HL: 0.60 ± 0.00; HW: 0.63 ± 0.01; CI: 105.00 ± 1.83; FW: 0.39 ± 0.01; SL: 0.17 ± 0.00; SI: 27.78 ± 0.48; MW: 0.69 ± 0.01; ML: 1.38 ± 0.02. Whole body brown, head and thorax sometimes slightly darker than abdomen, appendages paler than rest of body. Head subtrapezoidal, occipital margin rounded, anterior margin of clypeus presenting small concavity, eyes large and oval. Antennae with thirteen segments, antennal club with five segments. Mesosoma elongated, with anterior gibbous part formed by prothorax, mesothorax and part of metathorax, and posterior part comparatively flat formed by part of metathorax and propodeum. Promesonotal suture well marked, pronotum and mesonotum convex in lateral view, rounded on side. Metathorax arched, consisting of subvertical and subhorizontal part. Subhorizontal part, in dorsal view, becomes very narrow in proximity of subvertical part. Propodeum not much thicker than horizontal part of metathorax in lateral view. Propodeal spines are absent and only represented by two tubercles. Petiole elongated, petiolar node and postpetiolar node rounded, both dorsally present shallow longitudinal suture in center. Petiole in dorsal view presents significantly enlarged area between node and articulation with propodeum. Scape very short, covered by rare decumbent setae, decumbent to subdecumbent setae also present on head, mesosoma and legs, few erect setae on mesosoma, coxae, petiole and postpetiole and suberect to erect setae on gaster. Head finely reticulated, rest of body smooth and shiny.
Queen redescription
(
Figs 37, 38, 42
). Measurements and indices (6 individuals, 5 localities): HL: 1.35 ± 0.40; HW: 1.30 ± 0.02; CI: 96.33 ± 1.55; FW: 1.11 ± 0.02; SL: 1.22 ± 0.02; SI: 93.60 ± 1.55; MW: 1.24 ± 0.02; ML: 2.30 ± 0.04. Whole body ferruginous, with darker areas on gaster. Head subrectangular, lateral surface below eyes rounded, posterior margin of head straight. Anterior margin of clypeus slightly convex, mandibles rounded. Antennae with twelve segments, antennal club with four segments. Pronotum rounded in dorsal view, propodeal spines horizontal and with wide base. Petiole with long peduncle and node convex on both sides, postpetiole with anterior concave side and posterior slightly convex side. Entire head, except clypeus and occipital margin, densely covered with longitudinal striae. Long and more marked striae are subparallel to each other. Between them, less marked striae can be found often crossing each other. Mesosoma mostly shiny, with horizontal striae appearing in proximity of sutures, across propodeum and posterior faces of petiole and postpetiole. Adpressed to decumbent setae on antennae, suberect to mostly erect setae on head, dorsal part of mesosoma, of petiole and postpetiole and all over gaster. Long setae extending down from clypeus. Adpressed to decumbent setae on legs.
Systematic position.
Aphaenogaster sicula
first appears as
Aphaenogaster subterranea
var.
subterraneo-splendida
in
EMERY & FOREL (1879)
, but this is a
nomen nudum
(
EMERY 1908
). Consequently, it was then described by
EMERY (1908)
who considered it a subspecies of
A. crocea
.
Aphaenogaster sicula
was finally elevated to species-rank by
SCHEMBRI & COLLINGWOOD (1981)
on the basis of its worker morphology. However,
SCHEMBRI & COLLINGWOOD (1981)
based their judgment exclusively on misidentified material of
A. fiorii
stat. nov.
from
Malta
. Despite this fact, due to the degree of morphological differences from any other congeneric species, relevant in all three castes (see also comparative diagnosis), we surely agree to consider it a
bona species
.
Figs 20–28. Males in dorsal, lateral (scale bar: 0.50 mm) and head view (scale bar: 0.25 mm). 20, 21, 26 –
Aphaenogaster fiorii
Emery, 1915
,
stat. nov.
, non-type male from Bosco di Aci S. Antonio, Sicily, Italy. 22, 23, 27 –
A. sicula
Emery, 1908
, non-type male from Ficuzza, Sicily, Italy. 24, 25, 28 –
A. trinacriae
sp. nov.
, paratype male AACI-ANTP003/1 from M. Sparagio, Sicily, Italy. Photos by Enrico Schifani.
Comparative diagnosis.
Worker
.
The color pattern is unique among the sympatric species, having the head darker than mesosoma, both ferruginous, and the gaster very dark (somewhat resembling the Maghrebian
A. strioloides
). In addition,
A. sicula
presents a very reduced promesonotal suture (especially different in comparison to
A. trinacriae
sp. nov.
) with a more convex mesonotum than
A. fiorii
stat. nov.
, while still lacking the metanotal groove marked like in
A. subterranea
s. l.
in lateral view (
Figs 12
‒
19
). Moreover,
A. sicula
is less sculptured than most similar species (except for example the very different
A. crocea lenis
Santschi, 1911
) and its head appears shiny if compared to that of
A. trinacriae
sp. nov.
It is also a relatively small species.
Male.
Only some of the
Aphaenogaster
males present a mesosoma with an anterior gibbous part and a comparatively flat posterior part like
A. sicula
. Among the sympatric species that do so,
A. splendida
can be easily distinguished by different shape of the metathorax, forming a decisively slenderer area in front of the propodeum in lateral view (see
EMERY 1908
,
1916
).
Aphaenogaster sardoa
male (
SANTSCHI 1911
) is larger, its metathorax does not form slenderer part in front of the propodeum, it possesses a visibly less gibbous anterior part and more abundant erect setae on the body.
Aphaenogaster fiorii
stat. nov.
and
A. trinacriae
sp. nov.
are the most similar, but do not possess the aforementioned slenderer part in front of the propodeum in the flatter part of the mesosoma. In addition,
A. fiorii
stat. nov.
is much lighter in color and presents more developed and differently shaped tubercles on the propodeum, while
A. trinacriae
sp. nov.
is distinguished by the well-developed enlarged flat areas on the sides of the propodeum (better observed in dorsal view). The shape of the mesosoma also distinctively separates
A. sicula
from the somewhat similar Maghrebian species:
A. crocea
(see
CAGNIANT 1966
),
A. faureli
(see
CAGNIANT 1969
),
A. mauritanica
(see
SANTSCHI 1932
,
CAGNIANT 1987
),
A. nadigi
(see
CAGNIANT 1987
),
A. strioloides
(see
SANTSCHI 1932
), and
A. theryi
(see
CAGNIANT 1986
,
1996
).
Queen
.
Among sympatric species the mesosoma shape in
A. sicula
is only similar to that of
A. fiorii
stat. nov.
,
A. trinacriae
sp. nov.
and
A. subterranea
s. l.
However,
A. fiorii
stat. nov.
is chromatically very different, and
A. subterranea
s. l.
is also often darker. Moreover,
A. sicula
is unique for its short and thick spines. The scarcity of available information does not allow a proper comparison with the Maghrebian forms.
Distribution and biogeographical remarks
(
Fig. 45
).
Aphaenogaster sicula
seems to inhabit the whole Sicilian territory where the required ecological conditions are met and is also present in a small area in the southern part of Calabria. Further investigation is probably needed to establish its northernmost range limit. Land connections between Calabria and Sicily occurred relatively frequently during the later stages of the Pleistocene (
BONFIGLIO et al. 2002
), and a Siculo-South Calabrian chorotype was established for the Italian fauna (STOCH & VIGNA TAGLIANTI 2006). Dispersion of
A. sicula
most likely occurred from Sicily to Calabria. Its alleged presence in the Maltese islands was based exclusively on misidentified specimens of
A. fiorii
stat. nov.
as already mentioned. Finally,
BARONI URBANI (1971)
interpreted BERNARD’ s (1958) record of
A. crocea
for Lampedusa as
A. crocea sicula
but MEI (1995) considered the original record by Bernard erroneous and based on a misidentification of
A. sardoa
. More recent collecting efforts only reinforce Mei’s hypothesis (ES, unpublished data; A. Scupola, unpublished data). A particularly aberrant record was published by
PETROV (2000)
for
Montenegro
(without any more precise locality), but it was most likely a result of misidentification (
KARAMAN 2011
).
Ecology.
Aphaenogaster sicula
inhabits clay soils, living in meadows most of the times, but also in garrigues or degraded Mediterranean maquis, and can also be found in
Pinus
afforestations at low altitudes. Nonetheless, it is generally associated with open habitats. It is collected between
35 m
and
840 m
.
Conservation.
Viable habitats for
A. sicula
seem to be abundant in its distribution range. Unless a massive change in land usage takes place, the species should not face particular threats. In addition, the data here presented (
Fig. 45
) may represent a significant underestimation of its distribution in
Sicily
.
Figs 29
‒
34. Males genitals, view of the inner face of lacinia and volsella (left) and of the subgenital plate (right). 29, 30 –
Aphaenogaster fiorii
Emery, 1915
,
stat. nov.
31, 32 –
A. sicula
Emery, 1908
. 33, 34 –
A. trinacriae
sp. nov.
Drawings by Antonio Alicata.
Biology.
Monogynous (no more than one queen per colony detected in the wild).
Phenology.
In captive colonies, sexuals began to leave the nest from the second week of July to the first week of August, but no attempt to form an actual nuptial flight was detected. In the wild it can be speculated that nuptial flights may start with the first relevant rains at the end of summer.