Description of Phloeosinus laricionis sp. n. (Coleoptera: Curculionidae, Scolytinae), a new bark beetle species from southern Europe
Author
Faccoli, Massimo
Author
Sidoti, Agatino
text
Zootaxa
2013
3722
1
92
100
journal article
10.11646/zootaxa.3722.1.8
56ce8197-76ab-42c5-b280-7a2a0a46d856
1175-5326
223200
9619141C-87E0-4572-BE67-2A31F6144EAE
Phloeosinus laricionis
Faccoli & Sidoti
,
new species
Description.
Male. Total length averaging 2.26 ± 0.11 mm (mean ± sd) and ranging 2.08–2.53 mm. Color of mature adults dark brown or black, shining; pronotum slightly darker than elytra (
Figs 1
,
2
). Frons with a moderately impressed, impunctate, smooth and shining concavity from the epistoma to the level of the eyes (
Fig. 3
); area around concavity dull and finely punctate, spaces among punctures with feeble but visible reticulation. Upper margin of the concavity with a small tubercle emerging from the middle of frons (
Fig. 3
). Frons with scattered, few, long yellow setae, directed centrally. Setae shorter in the upper part of frons (
Fig. 3
). Antenna composed by scape, pedicel and 4 segments (
Fig. 4
); club and funicle of the same color, uniformly dark-brown (
Fig. 2
); club appearing 4-segmented, ovate, shining; club tip and sutures with abundant vestiture of uniformly short pale setae; first segment with straight sutures, second segment slightly arcuate, third segment strongly arcuate (
Fig. 5
).
Pronotum short, stout, 1.44 ± 0.05 (1.36–1.56) times wider than long, widest at the base and strongly constricted in the anterior third, where the sides are strongly arcuate (
Fig. 1
). Surface shining, densely, deeply and homogeneously punctured. Vestiture of moderately abundant yellow setae of two kinds, one of sparse, long and semierect setae directed posteriorly, and denser along lateral areas of pronotum; the other of very fine, fluffy pale setae adjoining to the surface and usually paired (
Figs 1
,
6
). Anterior margin of pronotum with a row of dense, short yellow setae (
Figs 1
,
2
,
6
).
Elytra dark brown in mature specimens, paler than pronotum and body (
Figs 1
,
2
). Elytra 1.6 ± 0.03 (1.55– 1.69) times longer than wide, 2.6 ± 0.1 (2.43–2.81) times longer than pronotum. Anterior margin of elytra raised, granulated and wrinkled, especially on striae 2, slightly rounded and not interrupted in the scutellar area (
Figs 1
,
2
).
Sides subparallel, converging posteriorly in the posterior third (
Fig. 1
). Disc shining. Vestiture like on pronotum: long, semierect yellow setae scattered on disc but denser on declivity and along the lateral margins of elytra, intermixed with denser short, fine, fluffy bifurcated setae adjoining to the surface (
Figs 1
,
2
). Interstriae apparently more hairy than striae. Elytral interstriae elevated, 1.5–2.0 times as wide as the striae; elytral striae with uniseriate rows of small, deep and closely spaced fine punctures; striae 4 and 6 not reaching the apex of elytra. Declivity broadly rounded, beginning at distal third of elytra; declivity with fine and acutely pointed, setiferous tubercles distributed along the odd interstriae 1–7; striae 2 on the declivity wide, strongly impressed but broadly convex to flat, shining, with few scattered short setae (
Figs 1
,
2
). Legs almost dark-brown, same color as elytrae (
Fig. 2
).
FIGURE 1
.
Phloeosinus laricionis
, dorsal view.
FIGURE 2
.
Phloeosinus laricionis
, lateral view.
Female. Similar to male, but frons flat, without concavity, only with a flat median punctated area (
Fig. 7
); rest of frons hairy, punctated, finely sculptured but not granulated. Central tubercle of frons smaller and less easily visible. Striae 2 on the declivity slightly less impressed (
Fig. 7
). Males and females similar in size.
Type
material.
All from the island of Sicily, in
Italy
. The material was collected in
2010–2012
from the locality of Primo Monte (
37° 47' 08" N
,
15° 03' 37" E
,
1655 m
a.sl.), Monte Vetore (
37° 41' 27" N
,
14° 59' 00" E
,
1820 m
a.s.l.), and Cubania (
37° 45' 07" N
,
15° 04' 37" E
,
1330 m
a.s.l.). The investigated specimens include the
holotype
and 60
paratypes
, of which: 2 from Primo Monte,
iv.2010
; 6 from Monte Vetore,
x.2010
; 8 from Primo Monte,
iv.2011
; 31 from Monte Vetore,
x.2011
; 3 from Primo Monte
14.vi.2012
; 9 from Monte Vetore,
ii.2012
; 1 from Cubania
14.vi.2012
. All specimens were collected by A. Sidoti from
Phloeosinus
-killed
P. nigra
ssp.
laricio
.
FIGURE 3
. Frons of male. Note central tubercle, concavity and setae distribution.
FIGURE 4.
Whole antenna: note scape, pedicellus and the 4 following segments.
FIGURE 5.
Antennal club. The sutures of the club are straight on the first segment, slightly arcuate on the second, and strongly arcuate on the third.
Etymology.
The Latin epithet,
laricionis
, was chosen to reflect the only host tree known,
P. nigra
ssp.
laricio
.
Collections and depositories.
The
holotype
is deposited in the Natural History Museum, London (
England
).
Paratypes
are distributed in the collections of the University of Padua (
Italy
), Natural History Museum (London,
England
), Naturhistorisches Museum Wien (Vienna,
Austria
), and Miloš Knížek (Prague,
Czech Republic
).
Host plants and ecology.
The only host plant so far known is
P. nigra
ssp.
laricio
. In the monitored stands,
P. laricionis
was found in the middle to upper part of the stem of young pine trees about 30 years old.
P. laricionis
was always associated with small pine bark beetle species of the genus
Pityogenes
Bedel
and
Pityophthorus
Eichhoff
infesting thin barks of stressed trees. Gallery systems are longitudinal, with one or two egg tunnels per system.
Differential diagnosis and identification key.
Phloeosinus laricionis
is morphologically very closely related to the
Phloeosinus
species living on cedars,
P. ce d r i
,
P. acatayi
and
P. pfefferi
, known respectively from
Algeria
and
Morocco
on
Cedrus atlantica
(Endlicher)
,
Turkey
and
Syria
on
Cedrus libani
Richard
, and
Cyprus
on
Cedrus brevifolia
(Hook.)
. Along the declivity, all these species have the elytral interstriae 1–7 provided with small single tubercles.
Phloeosinus laricionis
can be distinguished from
P. c e d r i
and
P. acatayi
by the remarkably larger size, the tuberculate frons, the host plant and the distribution area. Although similar in size,
P. laricionis
may be separated from
P. pfefferi
by the smaller, deeper and closer fine punctures of the elytral striae making the elytral interstriae 1.5–2.0 times as wide as the striae; differently,
P. pfefferi
shows elytral striae with large, shallow and spaced points making the elytral interstriae as wide as the striae. Different hosts and distribution can also help in species separation.
FIGURE 6
. Male of
Phloeosinus laricionis
, lateral view of head and pronotum.
FIGURE 7
. Frons of female. Note the flat median punctate area, without concavity.
The following identification key is intended to facilitate separating
P. l a r i c i o n i s
from morphologically similar
Phloeosinus
species. The arrangement of the species in the key is not phylogenetic.
1 Large, blunt tubercles along the declivity of the odd interstriae 1–7. Elytral striae with large, shallow, widely spaced punctures; elytral interstriae as wide as the striae...................................................................... 2
- Fine, acutely pointed tubercles along the declivity of the odd interstriae 1–7. Elytral striae with small, deep and close punctures; elytral interstriae 1.5–2.0 times as wide as the striae..................................................... 3
2(1) Small species, <2.2 mm long. Elytra covered by fluffy setae and dull surface. In
Turkey
and
Syria
on
Cedrus libani
...............................................................................................
P. acatayi
Schedl
- Large species,> 2.2 mm long. Elytra with few fluffy setae and generally shining surface. In
Cyprus
on
Cedrus brevifolia
............................................................................................
P. pfefferi
Knížek
3(1) Small species, <
2 mm
long. Frons crenulate-granulate but without tubercle. Elytra brown. In
Algeria
and
Morocco
on
Cedrus atlantica
.................................................................................
P. cedri
Brissout
- Large species,>
2 mm
long. Frons punctate, with a small central tubercle (in males). Elytra black. In Sicily (
Italy
) on
Pinus nigra ssp. laricio
............................................................................
P. laricionis