Revision of the genus Thyreocephalus and description of Afrus gen. nov. of Africa south of the Sahara (Coleoptera: Staphylinidae: Staphylininae)
Author
Janák, Jiří
Author
Bordoni, Arnaldo
text
Zootaxa
2015
4038
1
1
94
journal article
10.11646/zootaxa.4038.1.1
066e84f1-206b-40cb-a615-2126696b813d
1175-5326
289876
1B62B78C-AA59-4417-A4FC-1CC9CED745E0
Thyreocephalus
Guérin-Méneville, 1844
Thyreocephalus
Guérin-Méneville, 1844
: 10
;
Sharp, 1885
: 498
;
Cameron
, 1921
: 354
;
Steel, 1938
: 55
;
Blackwelder, 1943
: 490
; 1952: 390;
Coiffait, 1968
: 128
and 152;
Smetana, 1977
: 348
; 1982: 66;
Moore & Legner, 1979
: 76
,
Bordoni, 2002
: 210
; 2005a: 478; 2005b: 354; 2010: 318;
Navarette-Heredia et al. 2002
: 319
; Newton et al. 2001: 328 et 392, 2005: 48;
Janák, 2010
: 130
;
Asenjo et al. 2013
: 359
.
Linidius
Sharp, 1876
: 196
;
Steel, 1938
: 56
.
Saurohypnus
Sharp, 1885
: 501
;
Casey, 1906
: 373
;
Arnett, 1960
: 247
;
Moore, 1963
: 94
;
Moore & Legner, 1974
: 557
.
Indoscitalinus
Heller, 1900
: 5
;
Cameron
, 1932: 33;
Steel, 1938
: 55
;
Shibata, 1973
: 126
.
Type
species
:
Thyreocephalus jekelii
Guérin-Méneville, 1844
, established by
Lucas, 1920
by subsequent designation.
The following redescription is based on redescriptions by
Smetana (1982)
and
Janák (2010)
and is completed and extended for hitherto revised species from various regions.
Redescription.
Form elongate, stout, of large to very large size (
9–25 mm
).
Head variably punctate (
Figs. 24
,
127, 129
), punctures not forming semi-impressed rows of coalescent grooves, frontal grooves short or moderately long, ocular grooves less deep, inconspicuous or absent. Anterior margin of frons between antennal insertions extended into short and very wide, apically truncate process, limited at each side by rounded emargination, and slightly impressed dorsally. Eyes small, temples longer than length of eyes seen from above, evenly rounded, hind angles rounded or acute. Antennae geniculate, moderately short, antennal insertions separated from each other by distance about equal to distance separating each insertion from anteromedian margin of eye, first segment long, thickened towards apex, equal in length to at least the four following segments combined, second segment shorter than third, distal segments more or less transverse. Labrum completely chitinised, short, transverse, more or less lobate (
e.g
.,
Figs. 31
,
76
,
159
) or rounded (
Fig. 131
) apically, with long and strong apical setae. Mandible stout, lateral furrow reduced to vague impression at base. Maxillary palpi moderately long, segment 3 shorter than segment 2, segment 4 longer and somewhat narrower than segment 3, subacute apically. Labial palpi moderately long, last segment distinctly longer than segment 2. Mentum short, transverse, pentagonal. Ligula divided. Gula very short, gular sutures contiguous or narrowly separated posteriorly.
Pronotum without dorsal rows of punctures, with one big puncture (without seta) close to anterior angles (
e.g.,
Figs. 23
,
25
); antesternal plate with a suture (
Fig. 26
); both superior and inferior line of pronotal hypomera strongly developed, superior line turning downwards well before middle, joining or almost joining inferior line next to front margin of procoxae and continuing onto front margin of pronotum (
Fig. 26
). Prosternum (
Fig. 26
) elevated medioposteriorly, without or with posteromedian carina, intercoxal process protruding, triangular (
Fig. 26
); epimera present. Mesosternum very short, transverse, widely separating middle coxae. Metasternum very long.
Elytra overlapping at suture (
Figs. 22, 23
). Legs moderately long; protarsi simple (not dilated) in either sex, first four segments gradually becoming shorter, last segment about as long as three preceding segments combined; protibiae with numerous strong spines on outer margin; mesotibiae strongly spinose, with apical ctenidium which extends onto inner margin backwards to about middle and with another similar ctenidium above it; first segment of mesotarsus and metatarsus about equally long as second, last segment about as long as preceding segments combined; metatibiae spinose on outer margin, with apical ctenidium which extends onto inner margin backwards to about middle, and with another similar ctenidium above it extending along outer margin to about middle (
Figs. 27, 28
).
FIGURES 22–23.
22,
Thyreocephalus brunneiventris
(Tottenham)
—
T. pilosus
group; 23,
T. alluaudi
(Fauvel)
—
T. ater
group. Scale 1 mm.
FIGURES 24–28.
24,
Thyreocephalus brunneiventris
(Tottenham)
; 25, 27,
T. alluaudi
(Fauvel)
; 26,
T. interocularis
(Eppelsheim)
; 28,
T. ferox
(Harold)
; 24, 25, head and anterior part of pronotum; 26, ventral side of pronotum (ap—antesternal plate, pr—prosternum, ip—intercoxal process, SL—superior line, IL—inferior line); 27, 28, metatibia (ac—apical ctenidium, sac—subapical ctenidium). Scale 0.5 mm.
FIGURE 29
. Distribution of species in
Thyreocephalus pilosus
group (● =
T. africanus
(Bernhauer)
, Δ =
T. brunneiventris
(Tottenham)
, ▲ =
T. pilosus
(Roth)
, ☆
T. pseudoafricanus
sp. nov
.
, ○
=
T. secretus
(Bernhauer)
, ★
=
T. tsingidianus
sp. nov
.
).
Abdomen (
Figs. 22, 23
) ‘Staphylininae-shaped’ with fourth or fifth segment broadest. Tergite 7 with complete membranous palisade fringe at its posterior margin (
Figs. 22, 23
).
Male
. Tergite and sternite 8 of male simple, not modified. Tergite 10 of male genital segment rather narrowly exposed between sclerites of tergite 9, strongly narrowed proximally (e. g.
Figs. 32
,
42
), sclerites of tergite 9 contiguous mediobasaly. Sternite 9 of male genital segment asymmetrical, located centrally (e. g.
Figs. 33
,
43
). Aedeagus with basal bulbus subovoid, median lobe of different length, symmetrical (e. g.
Figs. 34
,
79
) or assymetrical (
Figs. 69
,
91
) parameres and inner sac with shape of more or less long and wide ribbon with scales of different size.
Female. Genital segment with sternite proportionally short and two big supplementary sclerites that cover its proximal part (
Fig. 217
).
Differential diagnosis.
This genus differs from several other genera of
Xantholinini
in the absence of dorsal rows of punctures on the pronotum (together with
Achmonia
Bordoni, 2004
,
Afrus
gen. nov.
,
Agerodes
Motschulsky, 1858
,
Dibothroglyptus
Scheerpeltz, 1957
,
Domea
Bordoni, 2002
,
Eachamia
Bordoni, 2005
,
Eulissus
Mannerheim, 1830
,
Gauropterus
Thomson, 1860
,
Liotesba
Scheerpeltz, 1965
,
Oculolabrus
Steel, 1946
,
Ulisseus
Bordoni, 2002
), in the punctures on the head not forming semi-impressed rows of coalescent grooves (in contrast to
Gauropterus
), in the absence of longitudinal furrows on the dorsal side of the temples (in contrast to
Ulisseus
), in the anterior angles of pronotum not emarginated (in contrast to
Dibothroglyptus
), in the superior line turning downwards well before middle and joining or almost joining the inferior line next to the front margin of procoxae and continuing onto the front margin of pronotum (in contrast to
Achmonia
,
Agerodes
,
Domea
,
Eachamia
,
Eulissus
,
Liotesba
and
Oculolabrus
) and in presence of a subapical ctenidium on the metatibia (in contrast to
Afrus
gen. nov.
).
Geographical distribution.
This genus is characteristic of warm regions of the earth and is well represented in Africa,
Madagascar
, Central and South
America
, in the Oriental Region from
India
and
Nepal
to Sulawesi, the Sunda islands, and the
Moluccas
(
Bordoni 2002
).
Thyreocephalus
is particularly represented in the Australian Region (
Bordoni 2005a
,
2010
). The few species of
New Zealand
are introduced (
Bordoni, 2005b
). Two species are known from
America
North of
Mexico
(
Smetana 1982
).
Bionomics.
The species belonging to this genus were collected in rotting matter, in debris, under stones, sometimes in dung, in carrion of small animals, in rotting fruits on the ground; some of them are probably subcorticicolous.
The pre-imaginal stages of
T. albertisi
were described by
Marucci & Clancy (1952)
;
Paulian (1941)
described a larva attributed to
T. anachoreta
sensu auct. (=
T. amphidaseus
Bordoni, 2002
).
Dettner (1987)
studied the defensive glands of this genus.
In Africa the genus can be divided into 9 distinct species groups, characterised by different composition of setiferous punctures on head, general appearance including colour of the body and the shape of the labrum. These species groups do not always reflect natural relationship, but can help with the identification of species.