Three new species of the genus Chydaeus (Coleoptera: Carabidae) from Vietnam

2013·0.21 MB·

by  B. M. Kataev

ZOOSYSTEMATICA ROSSICA, 22(1): 69–79 25 JUNE 2013
Three new species of the genus Chydaeus (Coleoptera: Carabidae)
from Vietnam
Три новых вида рода Chydaeus (Coleoptera: Carabidae)
из Вьетнама
B.M. KATAEV* & D.N. FEDORENKO
Б.М. КАТАЕВ, Д.Н. ФЕДОРЕНКО
B.M. Kataev, Zoological Institute, Russian Academy of Sciences, 1 Universitetskaya Emb., St Petersburg 199034,
Russia. E-mail: [email protected]. *Corresponding author.
D.N. Fedorenko, A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, 33 Leninsky
prospect, Moscow 119071, Russia. E-mail: [email protected]
Three new species of the genus Chydaeus Chaudoir, 1854 are described from Vietnam: C.
abramovi sp. nov. (Lao Cai Province), C. majusculus sp. nov. (Lam Dong and Khanh Hoa
provinces) and C. dalatensis sp. nov. (Lam Dong Province). A key for identification of six spe-
cies and subspecies of Chydaeus known from Vietnam is provided.
Описаны три новых вида рода Chydaeus Chaudoir, 1854 из Вьетнама: C. abramovi sp. nov.
(провинция Лаокай), C. majusculus sp. nov. (провинции Ламдонг и Кханьхоа) и C. dala-
tensis sp. nov. (провинция Ламдонг). Составлена таблица для определения шести видов
и подвидов Chydaeus, известных из Вьетнама.
Key words: ground beetles, taxonomy, Vietnam, Coleoptera, Carabidae, Harpalini, Chydaeus,
new species
Ключевые слова: жужелицы, таксономия, Вьетнам, Coleoptera, Carabidae, Harpalini,
Chydaeus, новые виды
INTRODUCTION this paper, three new species are described,
one from North Vietnam and two from
The predominantly Oriental genus
South Vietnam, based on material collected
Chydaeus Chaudoir, 1854 comprises more
by several expeditions of the Russia–Viet-
than 45 species, with almost half of them
nam Tropical Center to Vietnam in 2002–
described during the last decade (Ito, 2002,
2009. In Vietnam the members of Chydaeus
2003, 2006; Kataev et Schmidt, 2002, 2006;
are confined to mountain regions where
Baehr, 2004, 2007; Kataev et al., 2012);
they occur at altitudes of 1400–2100 m.
however, many species remain undescribed.
The Chydaeus fauna of Vietnam is still poor-
MATERIAL AND METHODS
ly investigated. Three species, C. salvazae
Schauberger, 1934, C. andrewesi Schau- The following abbreviations are used for
berger, 1932, and C. bedeli (Tschitschérine, the depositories of the specimens examined:
1897), have been recorded from North Viet- collection of J. Schmidt, Marburg, Germa-
nam, the latter two being represented there ny (CS); collection of D.W. Wrase, Berlin,
by separate subspecies: C. andrewesi kumei Germany (CWR); Moscow Pedagogical
Ito, 1992 and C. bedeli vietnamensis Kataev University, Moscow, Russia (MPU); ref-
et Schmidt, 2002; but no Chydaeus species erence collection of D.N. Fedorenko at
have been recorded from South Vietnam. In A.N. Severtsov Institute of Ecology and
© 2013 Zoological Institute, Russian Academy of Scienсes
70 B.M. KATAEV & D.N. FEDORENKO. NEW SPECIES OF CHYDAEUS FROM VIETNAM
Evolution, Russian Academy of Sciences, Microsculpture. Present in both sexes
Moscow, Russia (SIEE); Zoological Insti- on head, pronotum and elytra, consisting
tute, Russian Academy of Sciences, St Pe- largely of fine, more or less isodiametric
tersburg, Russia (ZIN). meshes; meshes in central portion of prono-
Measurements were taken as follows: tum and on inner intervals of elytra slightly
body length, measured from the anterior transverse.
margin of the clypeus to the elytral apex; Head. Comparatively large (HWmax/
width of head, measured as the maximum PWmax = 0.73–0.74 and HWmin/
linear distance across the head includ- PWmax = 0.60–0.62), impunctate. Tempora
ing the compound eyes (HWmax), and rather short, nearly flat or slightly convex,
as the minimum linear distance across sloped to neck. Clypeus arcuately emargin-
the neck constriction just behind the eyes ate and vaguely bordered apically. Clypeo-
(HWmin); length of pronotum (PL), meas- frontal suture slightly impressed. Frontal
ured along its median line; length of elytra foveae small, moderately deep; clypeo-oc-
(EL), measured from the basal border at ular prolongations short, not reaching su-
scutellum to the apex of the sutural angle; praorbital suture, deepened at clypeus. Su-
maximum width of pronotum (PWmax) praorbital seta situated just before level of
and of elytra (EW), both measured at their hind margin of each eye. Eyes large, rather
broadest point; minimum width of prono- convex (HWmax/HWmin = 1.18–1.23).
tum (PWmin), measured at its narrowest Labrum distinctly emarginate apically. Left
point near the hind angles; length and width mandible subtruncate at apex. Ligular scler-
of metepisterna, measured along their inner ite slightly widened and truncate at apex.
and anterior margins, respectively. Antennae slender, surpassing pronotal basal
margin by approximately one apical anten-
TAXONOMY nomere; middle antennomeres (5–7) each
about 2.0–2.3 times as long as wide.
Order COLEOPTERA
Pronotum. Rather transverse (PWmax/
Family CARABIDAE PL = 1.49–1.54), narrowed basad (PWmax/
PWmin = 1.17–1.21) and widest at about
Tribe HARPALINI
a third from apex. Sides rounded in apical
Genus Chydaeus Chaudoir, 1854 two-thirds and broadly sinuate in basal
Chydaeus abramovi sp. nov. third, with one setigerous pore slightly
before middle. Apical margin shallowly
(Figs 1, 4–9)
emarginate, bordered only laterally. Bas-
Holotype. Male; Vietnam, “Lao Cai Prov., al margin more or less straight medially,
6 km W of Sa Pa, N slope of Phansipan Mt. Area, slightly oblique laterally, distinctly bor-
2000–2100 m, near Tram Don (base of Hoang
dered throughout, slightly longer than
Lien Nat. Park), 22°21´N, 103°46´E, V.2005,
apical margin and noticeably shorter than
A.V. Abramov leg. (‘Exp. of Russia-Vietnam
elytral base between humeral angles. Apical
Tropical Centre’)” (ZIN).
angles clearly protruded anteriad, narrow-
Paratypes. 1 male, 1 female; Vietnam, Lao
Cai Prov., environs of Sa Pa, ca 1600 m, May ly rounded at apices. Basal angles almost
2006, A.E. Anichkin leg. (SIEE). right, only slightly greater than 90°, rather
Description. Size. Body length 12.3– sharp, without denticle at apices. Pronotal
12.9 mm; body width 5.1–5.6 mm (in holo- disc convex, depressed laterobasally, mark-
type, 12.5 and 5.3 mm, respectively). edly sloped to apical angles. Lateral depres-
Color. Black, slightly shiny on dorsum. sions developed from apical angles to basal
Apical half of apical palpomeres, antenno- margin, narrow in apical third and evenly
meres 4–11 and tarsi (occasionally also fem- widened (more strongly in holotype than in
ora and tibiae) slightly paler, blackish brown. paratypes) behind lateral seta. Basal foveae
© 2013 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 22(1): 69–79
B.M. KATAEV & D.N. FEDORENKO. NEW SPECIES OF CHYDAEUS FROM VIETNAM 71
Figs 1–3. Chydaeus, habitus, holotype: 1, C. abramovi sp. nov.; 2, C. majusculus sp. nov.; 3, C. dalat-
ensis sp. nov.
narrow, reaching pronotal base, sharply de- slightly convex, evenly narrowed to apices,
limited within somewhat deep laterobasal impunctate. Umbilicate setal series without
depressions; areas between basal foveae and distinct gap at middle.
between basal foveae and lateral depres- Hind wings fully developed.
sions slightly convex. Pronotal surface very Ventral surface of body. Prosternum
finely, densely and irregularly punctate only smooth and glabrous. Proepisterna (pro-
within lateral and laterobasal depressions. pleura) smooth, at most vaguely micropunc-
Elytra. Moderately wide (EL/EW = tate. Prosternal process slightly prominent,
1.45–1.50, EL/PL = 2.74–2.83, EW/ not produced posteriad. Metepisterna nar-
PWmax = 1.24–1.27), widest behind mid- row, about 1.7 times as long as wide, strong-
dle, slightly diverging at sides medially, not ly narrowed posteriad (Fig. 4). Sternite VII
fused along suture. Humeri subangulate, (last visible) in both sexes with two pairs of
rounded at apices, each with a tiny den- setae along apical margin, with apex slight-
ticle visible only from behind. Subapical ly concave in male and rounded in female.
sinuations shallow. Sutural angles mark- Tergite VII (last visible) of female angularly
edly less than 90°, in both sexes very nar- rounded at apex.
rowly rounded at apices. Basal borders Legs. Metacoxa without posteromedial
slightly sinuate, joined with lateral edge at setigerous pore or any additional setigerous
very obtuse, almost indistinct angle. Striae or nonsetigerous foveae medially. Metafe-
impunctate, impressed along entire length. mur with two setae along posterior mar-
Parascutellar striole long, approximately as gin. Protibia with one ventroapical spine,
long as total width of intervals 1–3 or 1–5 outer margin with two stouter spines and
basally, with basal setigerous pore. Intervals also two slenderer spines apically in male,
© 2013 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 22(1): 69–79
72 B.M. KATAEV & D.N. FEDORENKO. NEW SPECIES OF CHYDAEUS FROM VIETNAM
Figs 4–9. Chydaeus abramovi sp. nov.: 4, left metepisternum; 5, apex of median lobe (holotype); 6, 7,
median lobe (holotype); 8, laterotergite IX and stylus; 9, stylus. Dorsal view (5, 7), lateral view (6,
9), ventral view (4, 8). Scale bars: A = 1.0 mm (4, 6–9); B = 0.5 mm (5).
and with four uniform, stout spines in fe- Aedeagus (Figs 6, 7). Median lobe
male. Tarsi glabrous dorsally, tarsomere 5 slender, arcuate in lateral view and nearly
with four (occasionally three) pairs of lat- straight in dorsal view, convex on ventral
eroventral setae. Metatarsus approximately side in apical half before terminal lamella.
equal in length to HWmin in male, slightly Basal bulb relatively small. Terminal lamella
shorter in female; tarsomere 1 noticeably (Fig. 5) directed ventrad, somewhat flat, tri-
longer than tarsomere 2, but shorter than angular in dorsal view, slightly longer than
tarsomeres 2+3. In male, protarsus mark- wide, blunted at apex and with triangular
edly enlarged (tarsomeres 2–4 much wider depression on dorsal side basally; apical ca-
than long, slightly narrower than protibia pitulum very small, slightly prominent ven-
at apex; tarsomere 1 about as long as wide), trad and dorsad. Apical orifice in dorsal po-
and tarsomeres 1–4 with adhesive vestiture sition, prolonged to basal bulb. Internal sac
ventrally; mesotarsus moderately enlarged without any distinct sclerotized elements
(tarsomere 1 slightly longer than wide; tar- (only patch of tiny spines apically present).
somere 2 approximately as long as wide; Comparison. Based on the metacoxa
tarsomere 3 noticeably wider than long; without an additional posteromedial se-
and tarsomere 4 distinctly smaller than tar- tigerous pore and the aedeagus with a flat,
somere 2 and 3, deeply concave apically), triangular terminal lamella, this new species
and tarsomeres 2–4 with adhesive vestiture belongs to the semenowi group (sensu Ka-
ventrally). taev & Schmidt, 2006). Within this group,
Female genitalia (Figs 8, 9). Apical sty- adults of C. abramovi sp. nov. are recognized
lomere clearly arcuate in ventral view and by the following characters: large body size,
moderately wide in lateral view. wide pronotum with rather deep laterobasal
© 2013 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 22(1): 69–79
B.M. KATAEV & D.N. FEDORENKO. NEW SPECIES OF CHYDAEUS FROM VIETNAM 73
depressions and sinuate sides, and very long margin of each eye. Eyes small and weakly
metepisterna. This new species is similar in convex (HWmax/HWmin = 1.13–1.16).
the penis structure to C. obtusicollis Schau- Labrum deeply emarginate at apex. Left
berger, 1932 but distinguished from it by mandible stout and clearly truncate at apex.
a shorter terminal lamella and the internal Antennae short, reaching basal third of pro-
sac lacking distinct spiny patches. notum; middle antennomeres (5–7) each
Etymology. This new species is named about twice as long as wide.
after our friend and colleague, theriologist Pronotum. Clearly transverse (PWmax/
A.V. Abramov (St Petersburg), who col- PL = 1.47–1.60), widest at about a third
lected the holotype. from apex and noticeably narrowed ba-
Distribution. Known only from Sa Pa en- sad (PWmax/PWmin = 1.23–1.31). Sides
vironments, Lao Cai Province, North Viet- rounded in apical two-thirds and broadly
nam, where it was collected at altitudes of sinuate in basal third, with one setigerous
1600–2100 m. pore slightly before middle (in holotype
with additional lateral seta before obliga-
Chydaeus majusculus sp. nov. tory one on right side). Apical margin shal-
lowly emarginate, bordered only laterally.
(Figs 2, 10–15)
Basal margin more or less straight medially,
Holotype. Male; Vietnam, “Lam Dong Prov., slightly oblique laterally, distinctly bor-
Bi Doup-Nui Nat. Res., Bi Doup Mt., N slope, dered throughout, almost equal in length
12°07´N, 108°39´44´´E, 1700–1900 m, 6.V. 2009, to apical one and shorter than elytral base
leg. D. Fedorenko” (ZIN).
between humeral angles. Apical angles
Paratypes. Vietnam: 2 males, Lam Dong
small and acute; basal angles obtuse, with-
Prov., 5 km E of Dinh K’No, 46 km W of Da Lat,
12°48´N, 108°23´E, 1500–1520 m, at light, 19– out denticle at apices. Pronotal disc convex,
depressed laterobasally, markedly sloped
21 Apr. 2010, A.M. Prokofiev leg. (MPU, SIEE);
1 female, Khanh Hoa Prov., Hon Ba Mt., ca 30 km to apical angles. Lateral depressions dis-
W of Nha Thang, 1500 m, 12°07´N, 108°57´E, cernible from apical angles to basal margin,
15–23 Apr. 2006, A.V. Abramov leg. (“Exp. of narrow in apical third (as wide as width of
Russia–Vietnam Tropical Centre”) (ZIN). antennomere 2) and evenly widened behind
Description. Size. Body length 10.5– lateral seta. Basal foveae oval, reaching pro-
13.0 mm; body width 4.8–5.7 mm (in holo- notal base, rather sharply delimited within
type, 13.0 and 5.7 mm, respectively). moderately deep laterobasal depressions;
Color. Black, shiny on dorsum. Palpi, an- areas between basal foveae and between
tennae and tarsi paler, brown, with anten- basal foveae and lateral depressions slightly
nomeres 1–6 partly slightly infuscate. convex. Pronotal surface distinctly and ir-
Microsculpture. Meshes on dorsum in regularly punctate basally and in lateral
both sexes present throughout, more or less depressions; finer punctation also present
isodiametric on head, weakly transverse on along anterior margin and along sides be-
pronotum and clearly transverse on elytra. yond lateral depressions.
Head. Rather large, with wide neck Elytra. Widest behind middle (EL/
(HWmax/PWmax = 0.74–0.76 and EW = 1.35–1.41, EL/PL = 2.74–2.91, EW/
HWmin/PWmax = 0.65–0.67), impunctate PWmax = 1.28–1.33), not fused along su-
(occasionally with few indistinct micro- ture, rounded at sides. Humeri subangulate,
punctures on frons). Tempora fairly long rounded at apices, each occasionally with a
and rather gently sloped to neck. Clypeo- tiny denticle visible only from behind. Sub-
frontal suture deepened. Frontal foveae apical sinuations distinct but shallow. Sutur-
small, not deep; clypeo-ocular prolonga- al angles sharp, not rounded at apices. Basal
tions shallow, reaching supraorbital suture. borders slightly sinuate, joined with lateral
Supraorbital seta situated at level of hind edge at very obtuse angle. Striae impunc-
© 2013 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 22(1): 69–79
74 B.M. KATAEV & D.N. FEDORENKO. NEW SPECIES OF CHYDAEUS FROM VIETNAM
Figs 10–15. Chydaeus majusculus sp. nov.: 10, left metepisternum; 11, apex of median lobe (holo-
type); 12, 13, median lobe (holotype); 14, laterotergite IX and stylus; 15, stylus. Dorsal view (11,
13), lateral view (12, 15), ventral view (10, 14). Scale bars: A = 1.0 mm (10, 12–15); B = 0.5 mm (11).
tate, impressed along entire length. Parascu- (last visible) of female angularly rounded
tellar striole present, approximately as long at apex.
as total width of intervals 1–2 basally, with Legs. As described for preceding species,
basal setigerous pore. Intervals slightly con- but tarsomere 5 with three or four pairs
vex, faintly narrowed to apices and weakly of lateroventral setae. Metatarsus in both
convex apically; two lateral intervals with sexes shorter than HWmin. In male, pro-
fine micropunctation. Umbilicate setal se- and mesotarsi markedly enlarged: protar-
ries without distinct gap at middle. someres 2–4 wider than long, slightly nar-
Hind wings fully developed in female rower than protibia at apex; mesotarsomere
and reduced to small scales in males. 2 slightly longer than wide and mesotarso-
Ventral surface of body. Prosternum mere 3 approximately as long as wide; pro-
smooth and glabrous. Proepisterna (pro- tarsomeres 1–4 and mesotarsomeres 2–4
pleura) smooth, at most with few scattered with adhesive vestiture ventrally.
mictopunctures. Prosternal process not Female genitalia (Figs 14, 15). Apical
prominent. Metepisterna about 1.4 times stylomere comparatively faintly curved.
as long as wide, strongly narrowed poste- Aedeagus (Figs 12, 13). Median lobe
riad (Fig. 10). Sternite VII (last visible) stout, rather strongly arcuate in lateral view
in both sexes with two pairs of setae along and almost straight in dorsal view, weakly
apical margin, with apex slightly concave convex or almost flat on ventral side me-
in male and rounded in female. Tergite VII dially. Terminal lamella (Fig. 11) clearly
© 2013 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 22(1): 69–79
B.M. KATAEV & D.N. FEDORENKO. NEW SPECIES OF CHYDAEUS FROM VIETNAM 75
curved ventrad (more noticeably so in api- terminal lamella and with two spiny patch-
cal quarter), flat, triangular, about three es in internal sac.
times as long as wide, narrowly rounded at Etymology. The species name is an adjec-
apex and with very small bud-like apical tive meaning “somewhat greater” and refer-
capitulum. Apical orifice slightly shifted to ring to a rather large body size of the new
right, prolonged to basal bulb. Internal sac species.
with two basal spiny patches. Distribution. Known from Khanh Hoa
Comparison. Chydaeus majusculus sp. and Lam Dong provinces, South Vietnam,
nov. belongs to the obscurus group (sensu at altitudes of 1500–1900 m.
Kataev & Schmidt, 2006), which is char- Bionomics. Holotype has been caught by
acterized by the metacoxa without addi- hand in leaf-litter of the smallest meadow
tional posteromedial setigerous pore and patch skirting tropical rain forest at a stony
the aedeagus with a long terminal lamella. brink, at the altitude of about 1900 m.
This new species is most similar to C. gestroi
Andrewes, 1928 from Sumatra in external Chydaeus dalatensis sp. nov.
characters and structure of the aedeagus, (Figs 3, 16–22, 25)
differing distinctly in the pronotum which
Holotype. Male; Vietnam, “Lam Dong Prov.,
is densely and rather coarsely punctate ba-
Bi Doup-Nui Ba Reserve, env. Long Lanh,
sally, and more finely so laterally and api- 12°10´44´´N, 108°40´44´´E, 1400–1600 m, 3–6.
cally. The pronotum of C. gestroi is almost IV.2008, leg. D. Fedorenko” (ZIN).
impunctate even basally, at most only with Paratypes. Vietnam, Lam Dong Prov.: 2 fe-
few very fine, indistinct punctures in basal males, same data as for holotype (ZIN); 11 males,
foveae and near lateral margins. In addition, 12 females, same data, but various dates between
C. gestroi is distinguished from the new 11 Apr. and 29 May 2008 (ZIN, SIEE, CS, CWR);
1 male, Da Lat (= Lang Biang) Plateau, Bi Doup
species by having the following features:
Mt., Da Nhiw Valley, 4 km N Lang Lonh, 9 Apr.
pronotum on average narrower and more
2002, S.V. Kruskop leg. (MPU); 2 females, 5 km
strongly narrowed basad; two lateral inter- E of Dinh K’No, 46 km W of Da Lat, 12°48´N,
vals of elytra smooth, without micropuncta- 108°23´E, 1500–1520 m, at light, 19–21 Apr.
tion; elytral basal border joined with lateral 2010, A.M. Prokofiev leg. (MPU, SIEE).
edge more or less arcuately, not forming a Description. Size. Body length 9.9–
distinct angle; tarsomeres slenderer; pro- 11.0 mm; body width 4.3–5.1 mm (in holo-
and mesotarsi in male less strongly wid- type, 10.2 and 4.4 mm, respectively).
ened; median lobe of aedeagus (see Kataev Color. Body black, shiny on dorsum;
& Schmidt, 2006: figs 114–116) less arcu- clypeus apically and mandibles basally in
ate, with comparatively smaller basal bulb some specimens slightly paler, dark reddish
and with terminal lamella shorter and less brown; palpi reddish brown; antennomere
flat, not bent ventrad in apical quarter. 1, tibiae and femora black, antennomeres
In appearance, C. majusculus sp. nov. 2–11 and tarsi blackish brown to reddish
is also similar to C. abramovi sp. nov., but brown, in most specimens antennomeres
clearly differs from the latter in the follow- 2–6 darker than antennomeres 7–11.
ing distinctive characters: head larger, eyes Microsculpture. Present throughout on
smaller and less convex, mandibles stouter dorsum. Head covered with fine isodiamet-
at apices, antennae shorter, not extended to ric meshes. Pronotum with fine microsculp-
pronotal basal margin, elytral microsculp- ture consisting of more or less isodiametric
ture finer and clearly transverse, pronotal meshes along base and sides and of weakly
punctation more distinct and more widely transverse meshes in central portion and at
distributed, metepisterna shorter, two lat- apical margin; in male meshes more or less
eral elytral intervals micropunctate, and effaced in central portion of pronotal disc.
median lobe of aedeagus with much longer Elytral microsculpture in male consisting
© 2013 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 22(1): 69–79
76 B.M. KATAEV & D.N. FEDORENKO. NEW SPECIES OF CHYDAEUS FROM VIETNAM
Figs 16–26. Chydaeus: 16–22, 25, C. dalatensis sp. nov. (holotype and female paratype); 23, 24, 26,
C. salvazae. Left metepisternum (16); laterotergite IX and stylus (17); stylus (18); apex of median
lobe (19, 23); median lobe (20–22, 24); apex of left elytron (25, 26). Dorsal view (19, 21–26), lateral
view (18, 20), ventral view (16, 17). Scale bars: A = 1.0 mm (25, 26); B = 1.0 mm (16–18, 20–22, 24);
C = 0.5 mm (19, 23).
of fine, more or less isodiametric meshes to neck. Clypeus very shallowly emargin-
on two or three lateral intervals apically ate and vaguely bordered apically. Clypeo-
and basally and in narrow area along basal frontal suture distinct, slightly deepened.
border, and of more or less effaced, weakly Frontal foveae small, moderately deep;
transverse meshes on remaining surface; in clypeo-ocular prolongations superficial and
female consisting of fine weakly transverse short. Supraorbital seta situated at level of
meshes on interval 1 throughout and on hind margin of each eye. Eyes of medium
intervals 2–7 in apical half of each elytron, size, rather convex (HWmax/HWmin =
and of distinct isodiametric, nearly granu- 1.15–1.24). Labrum distinctly emarginate
late meshes on remaining surface. apically. Left mandible clearly truncate at
Head. Comparatively large (HWmax/ apex. Ligular sclerite truncate at apex, with
PWmax = 0.73–0.77 and HWmin/ apical angles protruding laterally. Antennae
PWmax = 0.61–0.65), impunctate. Tempora slender, in male surpassing pronotal basal
moderately long, nearly flat, evenly sloped margin by half of apical antennomere, in fe-
© 2013 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 22(1): 69–79
B.M. KATAEV & D.N. FEDORENKO. NEW SPECIES OF CHYDAEUS FROM VIETNAM 77
male at most reaching pronotal base; middle length. Parascutellar striole present, short,
antennomeres (5–7) each about 1.5–1.9 about as long as total width of intervals 1
times as long as wide. and 2 basally; basal setigerous pore present.
Pronotum. Transverse (PWmax/PL = Intervals slightly convex. Umbilicate setal
1.46–1.61), noticeably narrowed basad series not interrupted or narrowly inter-
(PWmax/PWmin = 1.23–1.29) and widest rupted at middle.
at about a third from apex. Sides rounded Hind wings reduced to small scales.
along entire length, but in basal half less dis- Ventral surface of body. Prosternum
tinctly than in apical half; with one lateral covered with very fine short setae. Pro-
setigerous pore on each side slightly before sternal process not prominent. Proepisterna
middle. Apical margin very slightly concave (propleura) impunctate. Metepisterna (Fig.
or nearly straight medially, bordered only 16) narrow, markedly narrowed posteriad,
laterally. Basal margin nearly straight or about 1.2 times as long as wide. Sternite VII
very broadly rounded medially, oblique lat- (last visible) in both sexes with two pairs of
erally, bordered throughout, approximately setae along apical margin and rounded at
equal in length to apical margin and notice- apex. Tergite VII (last visible) of female an-
ably shorter than elytral base between hu- gularly rounded at apex.
meral angles. Apical angles acute, narrowly Legs. As described for preceding species,
rounded at apices, slightly protruded ante- but tarsomere 5 with three or four pairs of
riad. Basal angles distinct, obtuse, occasion- lateroventral setae. Metatarsus longer than
ally each with very small obliterate denticle HWmin but shorter than HWmax in male,
at apex. Pronotal disc moderately convex, slightly shorter than HWmin in female; tar-
depressed laterobasally, markedly sloped somere 1 distinctly longer than tarsomere 2
to apical angles. Lateral depressions some- but distinctly shorter than tarsomeres 2+3.
what deep, narrow apically (approximately In male, protarsus strongly enlarged (tarso-
as wide as width of antennomere 2), slightly meres 2–4 much wider than long, approxi-
widened to lateral seta and more strongly so mately as wide as or wider than protibia at
behind it, fused basally with wide and deep apex; tarsomere 1 about as long as wide),
laterobasal depressions. Basal foveae elon- and tarsomeres 1–4 with adhesive vestiture
gate, shallow, reaching pronotal base, area ventrally; mesotarsomeres 2–4 moderately
between them convex; area at basal angles enlarged (tarsomere 2 slightly longer than
flat or very weakly convex. Pronotal sur- wide, tarsomere 3 slightly wider than long,
face densely and distinctly punctate within tarsomere 4 distinctly smaller than tarso-
lateral and laterobasal depressions; in many meres 2 and 3 and deeply concave apically),
specimens finer punctation also present and tarsomeres 2–4 with adhesive vestiture
along apical margin and in some specimens ventrally.
also on disc. Female genitalia (Figs 17, 18). Apical
Elytra. Moderately wide (EL/EW = stylomere evenly curved.
1.36–1.44, EL/PL = 2.60–2.91, EW/ Aedeagus (Figs 20–22). Median lobe ar-
PWmax = 1.26–1.33), widest behind mid- cuate in lateral view, convex at middle ven-
dle, rounded at sides, not fused along su- trally, nearly straight in dorsal view (with
ture. Humeri subangulate, rounded at api- apex slightly directed to right), without
ces, each with a tiny, occasionally indistinct, apical capitulum. Terminal lamella (Fig.
denticle visible only from behind. Subapical 19) triangular in dorsal view, about twice as
sinuations moderately deep (Fig. 25). Su- long as wide; apex very narrowly rounded,
tural angles acute, blunted at apices in both nearly circular in cross-section; ventral
sexes. Basal borders slightly sinuate, joined side serrate and with narrow longitudinal
with lateral edge at obtuse angle. Striae depression, dorsal side with wide basal de-
impunctate, clearly impressed along entire pression. Apical orifice in almost dorsal po-
© 2013 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 22(1): 69–79
78 B.M. KATAEV & D.N. FEDORENKO. NEW SPECIES OF CHYDAEUS FROM VIETNAM
sition, only slightly shifted to left basally. yas: Sikkim and Nepal (Kataev & Schmidt,
Internal sac with two basal spiny patches. 2002; Kataev et al., 2012).
Comparison. This new species is very Bionomics. All the specimens of the type
similar in external morphology and struc- series have been collected in a flood-land
ture of the aedeagus to C. salvazae Schau- maize field at the altitude of about 1400 m.
berger, 1934 but easily distinguished from The adults seem to be rather frequent in ag-
it by having the apical orifice of the medi- rocenoses.
an lobe in an almost dorsal position (only
slightly shifted to the left basally) and the Key to species and subspecies
terminal lamella longer and thinner (Figs of Chydaeus known from Vietnam
22 and 24). Additionally, the median lobe
1. Metacoxa with additional posteromedial
of C. dalatensis sp. nov. is slenderer and has
pore. Apex of tergite VII in female protrud-
a relatively smaller basal bulb. The differ-
ing dentiformly posteriad . . . . . . . . . . . . . . . . . . .
ences in characters of external morphology . . C. bedeli vietnamensis Kataev et Schmidt
between the two species are rather insuf- – Metacoxa without additional posteromedial
ficient: microsculpture on head and pro- pore. Apex of tergite VII in female rounded .
notum is slightly more distinct and elytral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
subapical sinuation is usually deeper in C. 2. Metepisterna very long, about 1.7 times as
long as wide (Fig. 4). Pronotal basal angles
dalatensis sp. nov. than in C. salvazae (Figs
nearly right, only slightly greater than 90°.
25 and 26). Kataev & Schmidt (2006) treat-
Median lobe of aedeagus (Figs 6–7) with
ed C. salvazae as belonging to the separate,
wide, triangular terminal lamella; internal
monobasic salvazae group based on the pe-
sac lacking any spiny patches . . . . . . . . . . . . . . .
culiar features of aedeagus of this species: . . . . . . . . . . . . . . . . . . . . . . . C. abramovi sp. nov.
apical orifice shifted to the left; apex thick, – Metepisterna shorter, at most 1.4 times as
nearly circular in cross-section and lacking long as wide (as in figs 10, 16). Pronotal basal
capitulum. Since C. dalatensis sp. nov. is angles clearly obtusangular. Median lobe of
aedeagus with narrower terminal lamella; in-
apparently closely related to C. salvazae, we
ternal sac with one or two small spiny patch-
include it in the same group in spite of the
es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
fact that apical orifice of its aedeagus is in
3. Pronotal basal angles each with a small acute
quite different position. Thus, the shape of
denticle protruded laterad. Pronotum along
the terminal lamella remains the only char- sides with narrow lateral groove almost not
acter distinguishing the salvazae and seme- widened behind lateral seta. Terminal lamel-
nowi groups. This supports the idea (Kataev la of aedeagus very narrow and long, approxi-
& Schmidt, 2006) that Chydaeus is a rather mately 3.5 times as long as wide, with sides
monomorphic taxon demonstrating narrow only slightly converging to apex; internal sac
with one preapical spiny patch on right side .
or even indistinct gaps between groups of
. . . . . . . . . . . . . . . . . . . . C. andrewesi kumei Ito
more or less related species recognizable
– Pronotal basal angles not denticulate at api-
within this genus.
ces, at most each with a tiny obliterate den-
Etymology. The species name refers ticle. Pronotum along sides with narrow lat-
to the Da Lat Plateau in South Vietnam, eral depression widened posteriad. Terminal
where the type series was collected. lamella of aedeagus shorter, triangular; inter-
Distribution. This new species is known nal sac with two basal spiny patches . . . . . . . 4
only from the Da Lat (= Lang Biang) Pla- 4. Antennae shorter, not extended to pronotal
basal margin. Two or three lateral elytral in-
teau, Lam Dong Province, South Vietnam,
tervals minutely punctate. Microsculpture
at altitudes of 1400–1600 m. It seems to
on elytral disc in female consisting of fine
be a southern vicariant of C. salvazae. The
transverse meshes. Protarsomeres 2 and 3 in
latter is distributed over North Vietnam,
male narrower than protibia at apex. Termi-
South West China (Sichuan and Yunnan) nal lamella of aedeagus (Figs 12, 13) long, ap-
and is also found in the Central Himala- proximately three times as long as wide, and
© 2013 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 22(1): 69–79