Corrections to the classification of the Neotropical ant-like stone beetles misplaced in Euconnus Thomson (Coleoptera, Staphylinidae, Scydmaeninae). Part 1.
Author
Jałoszyński, Paweł
text
Zootaxa
2020
2020-03-24
4755
2
251
270
journal article
10.11646/zootaxa.4755.2.3
60cf9eb6-409b-40db-a6e6-a0bfadeb06fa
1175-5334
3731581
urn:lsid:zoobank.org:pub:8D3A61EC-17A4-4824-9D67-CAF1DECEDB36
Venezolanoconnus asserculatus
(L.W. Schaufuss)
,
comb. n.
Scydmaenus asserculatus
L.W.
Schaufuss, 1866: 68
.
Euconnus
(s. str.)
asserculatus
(L.W. Schaufuss)
;
Csiki (1919)
: 45
.
Euconnus
(
incertae sedis
)
asserculatus
(L.W. Schaufuss)
;
Franz 1967: 697
, 715.
(
Figs 40–43
)
Type material.
Syntype
:
COLOMBIA
:
♂
, five historical labels (
Fig. 41
): “asserculatus /
Schf
/ N
Granada
” [originally white, now darkened], “asserculatus /
Schauf. / Nov. Granada
” [originally white, now darkened], “
C. Schaufuss
1930” [white, printed], “
Syntypus
” [red, printed], “
♀
” [white, handwritten]; during the present study a new label was added: “
VENEZOLANOCONNUS
/
asserculatus
(
L.W.
Schaufuss
, 1866)
/ det.
P. Jałoszyński
, 2020” [white, printed] (
SDEI
).
Diagnosis.
Apical region of median lobe in lateral view projecting distad and curved ventrad; median lobe with long and sparse setae, distributed along its laterodistal margins.
Redescription.
Body of male (
Fig. 40
) stout and strongly convex, brown, setae slightly lighter than cuticle; BL
1.58 mm
.
Head (
Fig. 40
) broadest at large, strongly convex eyes, HL
0.25 mm
, HW
0.30 mm
; frons and vertex confluent, weakly convex, together about as long as broad; supraantennal tubercles weakly elevated; tempora distinctly shorter than eye in dorsal view, strongly convergent posteromesad, rounded. Vertex and frons with fine, inconspicuous punctures; setae short, sparse, suberect. Antennae (
Fig. 40
) slender, AnL
0.68 mm
; antennomeres I and II each elongate (II weakly so), III–V each about as long as broad; VI–X each distinctly transverse; XI indistinctly shorter than IX and X combined, about 1.3 × as long as broad.
FIGURES 40–43.
Venezolanoconnus asserculatus
(L.W. Schaufuss)
comb. n.
, syntype male. Dorsal habitus (40); original set of labels (41); aedeagus in ventral (42) and lateral (43) views.
Pronotum (
Fig. 40
) broadest near posterior 1/4; PL
0.40 mm
, PW
0.43 mm
. All margins rounded; inner antebasal pits present but indistinct, small, shallow and diffuse, connected by shallow but distinct transverse groove. Punctures on pronotal disc fine, inconspicuous; setae on dorsal region short, sparse, suberect, on sides replaced by long erect bristles (most broken off in the studied
syntype
).
Elytra (
Fig. 40
) together oval, broadest distinctly behind middle; EL
0.93 mm
, EW
0.78 mm
, EI 1.19; basal impressions short and shallow, humeral calli distinct, elongate, elytral apices separately rounded. Punctures and setae similar to those on median region of pronotal disc.
Hind wings not studied.
Legs moderately long and slender; unmodified.
Aedeagus (
Figs 42–43
) stout; AeL
0.20 mm
. Median lobe in ventral view broadest in subapical region, in lateral view with dorsal and ventral walls sinuate; endophallus with long C-shaped flagellum; each paramere with several long apical setae.
Female. Unknown.
Distribution.
Western
Colombia
(“ad flumen Rio Madalena”); “
Brazil
” in
Asenjo et al. (2013)
was in error.
Remarks.
Although
Franz (1988)
described
Venezolanoconnus
, he apparently did not recognize the previously (
Franz 1967
) redescribed
Scydmaenus asserculatus
as a member of this genus. Moreover,
Franz (1967)
misidentified the
syntype
housed at SDEI as a female, whereas it is a male. Species of
Venezolanoconnus
have small, sacklike and lightly sclerotized aedeagi, and it is easy to overlook and even lose the male copulatory organ during a careless dissection; this can explain Franz’s error.
The species originally described as
Scydmaenus asserculatus
can be easily recognized as a member of
Vene- zolanoconnus
by its general body form. The unique structure of the aedeagus confirms this placement. Strongly modified parameres, almost surrounding the median lobe and at least in their basal half as broad as the median lobe, co-occurring with an asymmetrical, broad and curved flagellum are found only in this Neotropical genus.
Venezolanoconnus asserculatus
is most similar to
V. andinus
Franz, 1988
of western
Venezuela
(redescribed by
Jałoszyński 2012
); especially their aedeagi have a similar shape and structure. However, these species clearly dif- fer in pronotal structures: in
V. andinus
the pronotum lacks antebasal pits and groove, whereas in
V. asserculatus
a shallow but well visible transverse groove is present, connecting a pair of indistinct pits. Moreover, in the aedeagus of
V. andinus
, there are numerous (~ 15) short setae distributed from middle to distal margin of the median lobe, not visible or poorly visible in the ventral view. In
V. asserculatus
, the aedeagus bears only a few conspicuously long setae distributed along the distal margin of the median lobe, and most of them are well-visible in the ventral view. The apical region of the median lobe in the lateral view has also a clearly different shape in these species.