Navigator, a new endemic genus of Cetoniinae (Coleoptera: Scarabaeidae) from Australia, with descriptions of two new species and behavioural studies
Author
Moeseneder, Christian H.
Author
Hutchinson, Paul M.
text
Zootaxa
2016
4173
6
530
556
journal article
38065
10.11646/zootaxa.4173.6.2
f9f36ad7-2af7-4b6f-bc33-37418b11470b
1175-5326
254767
AEBD61A6-37B5-4413-A9B1-7895D3EE53F4
Navigator
Moeseneder & Hutchinson
,
new genus
(
Figs. 1–11
,
13
,
14
C–D)
Type species
.
Pseudoclithria fossor
Lea, 1914
, hereby designated.
Included species
.
Pseudoclithria fossor
Lea, 1914
,
Pseudoclithria ruficornis
(
Westwood, 1874
)
,
Navigator pixii
Moeseneder & Hutchinson
new species
, and
Navigator interior
Moeseneder & Hutchinson
new species
Description
. Size
9.6–18.9 mm
. Form elongate ovate or ovate. Colour black or brown with metallic reflections.
Head
. Clypeus subquadrate to elongate; lateral margins divergent (
Fig. 1
A, detail 1), widest preapically (
Fig. 1
A, detail 2;
Fig. 1
C, detail 4); clypeolateral ridge present; anterior margin shallow arcuate to linear (
Fig. 1
A, detail 3); margins gradually inclined to moderate elevations (
Fig. 1
A, detail 4); disc coarsely punctate. Frons bearing low, distinct medial elevation; coarsely punctate. Antenna club enlarged in male, longer than length of antennomeres 2–7.
Thorax
. Pronotum weakly transverse, trapezoidal (
Fig. 1
C); basomedian margin weakly concave-linear (
Fig. 1
C, detail 1); lateral margins with broad medial angles (
Fig. 1
C, detail 2); disc coarsely punctate (
Fig. 1
C, detail 3). Scutellum base broad, elongate, finely or coarsely punctate. Elytron posthumeral arch weakly sinuate-linear (
Fig. 1
D, detail 1), slightly exposing metacoxa (
Fig. 1
D, detail 2), basal half parallel sided (
Fig. 1
D, detail 3), apical half broadly arcuate to apex (
Fig. 1
D, detail 4); mesepimeron slightly protruding (
Fig. 1
D, detail 5); humeral and apical umbones indistinctly raised (
Fig. 1
D, details 6, 7); sutural costa distinct, bearing two or more distinct narrow costae; disc coarsely punctate, mostly coalesced, eroding costal margins. Mesometasternal process undeveloped, present as low rounded declivous process between mesocoxae (
Fig. 1
F, detail 1).
Legs
. Protibia bidentate or tridentate, denticles elongate; protarsomeres elongate, simple. Mesotibia unidentate. Mesotarsomeres elongate, simple. Metafemur elongate, anterior margin arcuate. Metatibia elongate, broad or narrow, unidentate (
Figs. 1
H–J); internal spur spatulate in female (
Fig. 1
H, detail 1). Metatarsomeres elongate, simple.
Abdomen
. Sternites distinctly convex and distended in female (
Fig. 1
E, detail 1). Metasternum sparsely punctate medially, denser rugulose laterally. Pygidium concentrically rugose, female in normal plane (
Fig. 1
E, detail 2) to elevated (
Fig. 1
E, detail 3). Genitalia (
Fig. 2
). Phallobase 1.5 x length of parameres and widest near base of parameres. Parameres narrowing from base; margin sinuate or parallel, widening near apex; dorsal cleft basally acute-obtuse then attenuate to apex.
Differential diagnosis
. The following combination of characters distinguishes
Navigator
from other
Schizorhinini
genera. Size
9.6–18.9 mm
, colour with metallic reflections, clypeal anterior margin nearly linear, dorsal surfaces coarsely punctate, elytral costae distinct and narrow, male antennal club enlarged, female metatibial internal spur spatulate.
Navigator fossor
new combination
and
N. ruficornis
new combination
are transferred from the genus
Pseudoclithria
. Here we distinguish
Navigator
from the two remaining
Pseudoclithria
groups, which are the
type
species
P. hirticeps
(Macleay, 1871)
and all others, which we refer to as
Pseudoclithria
species. Specimens of
Navigator
are structurally, and based on our observations also behaviourally, similar to
Grandaustralis
Hutchinson & Moeseneder, 2013
,
Octocollis
Moeseneder & Hutchinson, 2012
, and to a lesser degree
Tapinoschema
Thomson, 1880
. The males of these genera possess greatly enlarged antennal clubs. Both sexes of these genera have a coarsely punctate head, pronotum, and elytra; clypeus with anterior margin sinuate to linear; mesometasternal process undeveloped (except moderately developed in
Tapinoschema
); and weakly sinuate to linear posthumeral arch.
Differences to
Pseudoclithria hirticeps:
Colour
with metallic reflections; matt in
P. hirticeps
. Elytra with two or more distinct, narrow costae; in
P. hirticeps
with single broad costa. Elytral posthumeral arch sinuate to linear; in
P. hirticeps
sinuate, exposing abdomen. Mesometasternal process undeveloped; bud-shaped in
P. hirticeps
. Female pygidium gradually convergent to apex; in
P. hirticeps
highly transverse with distinctly obtuse apex. Female metatibia internal spur spatulate; in
P. h i r t i c ep s
elongate, parallel. Male parameres (
Fig. 2
) narrowing from base, widening to apex; in
P. h i r t i ce p s
elongate attenuate to apex.
Differences to
Pseudoclithria
species: colour with metallic reflections; matt in
Pseudoclithria
species. Pronotum coarsely punctate; finely punctate in
Pseudoclithria
species. Posthumeral arch sinuate to linear; in
Pseudoclithria
species. sinuate, often exposing abdomen. Male antennal club greatly enlarged; in
Pseudoclithria
species. not distinctly enlarged. Elytra with two distinct, narrow costae; in
Pseudoclithria
species. with single low, wide costa. Legs elongate; in
Pseudoclithria
species. legs stout. Female metatibial internal spur spatulate; nonspatulate in
Pseudoclithria
species.
FIGURE 1
.
Navigator
characters. A—characters of the head (example
N. pixii
male): A1—margins laterally divergent, A2— head widest preapically, A3—shallow arcuate to linear anterior margin, A4—gradually inclined margins, A5—shallow preclypeus, A6—cross-section, A7—lateral declivity absent. B—characters of the head (example
N. ruficornis
female): B1— lateral declivity present, B2—deep preclypeus, B3—cross-section, B4—lateral declivity present. C—characters of the pronotum (example
N. pixii
male): C1—concave linear basolateral margin, C2—broad median angle of lateral margins, C3— coarsely punctate disc. D—characters of the elytra (example
N. pixii
male, except D9): D1—weakly sinuate-linear posthumeral arch, D2—slightly exposed metacoxa, D3—elytral basal half parallel sided, D4—apical half of elytra broadly arcuate to apex, D5—slightly protruding mesepimeron, D6–7—indistinctly raised apical umbone, D8—visible pygidium D9—pygidium not well visible (example
N. ruficornis
). E—characters of the female abdomen: E1—distinctly convex and distended sternites, E2—pygidium in normal plane (example
N. ruficornis
), E3—pygidium in elevated plane (example
N. pixii
). F—character of the abdomen: F1—undeveloped mesometasternal process. G—metacoxa posterolateral angle: G1—angulate (examples
N. pixii
and
N. ruficornis
), G2—broadly arcuate (example
N. fossor
), G3—spinose (example
N. interior
). H–K: characters of the metatibia: H—
Navigator fossor
female: H1—spatulate internal spur, H2—unidentate, H3—trispinose apex. I—
Navigator ruficornis
female: I1—large, median denticle, I2—trispinose apex. J—
Navigator interior
female: J1—small, median denticle. K—
Navigator pixii
male: K1—unispinose apex. Note: cross-sections in A and B are from clypeal anterolateral angle to clypeolateral margin, not in transverse axis.
FIGURE 2
.
Navigator
male aedeagi. A—
Navigator fossor
. B—
Navigator pixii
.
C—
Navigator ruficornis
.
Note: male
N. interior
are unknown.
Differences to
Octocollis
: Size
9.6–18.9 mm
;
16–19 mm
in
Octocollis
. Colour with metallic reflections; matt in
Octocollis
. Clypeus widest preapically; parallel in
Octocollis
. Pronotum widest basally; in
Octocollis
widest medially. Elytral costae distinct, narrow; indistinct in
Octocollis
. Female metatibial internal spur spatulate; unknown in female
Octocollis
. Parameres narrowing from base, broadening preapically; in
Octocollis
parameres broad with apical appendage.
Differences to
Grandaustralis
: Size
9.6–18.9 mm
;
18.5–25.5 mm
in
Grandaustralis
. Colour with metallic reflections; matt in
Grandaustralis
. Elytra with two distinct narrow costae; indistinct in
Grandaustralis
. Female metatibial internal spur spatulate; parallel in
Grandaustralis
. Parameres narrowing from base, broadening preapically; in
Grandaustralis
narrow at base, equal width to apex.
Differences to
Tapinoschema
: Size
9.6–18.9 mm
; 20.3–34.0 mm in
Tapinoschema
. Colour with metallic reflections; glossy in
Tapinoschema
.
Pronotal shape weakly transverse; in
Tapinoschema
distinctly transverse. Mesepimeron slightly exposed; in
Tapinoschema
distinctly exposed. Elytra with two distinct, narrow costae; indistinct in
Tapinoschema
. Mesometasternal process undeveloped; in
Tapinoschema
parallel or attenuate elongate. Female metatibia internal spur spatulate; parallel in
Tapinoschema
. Parameres narrowing from base, broadening preapically; in
Tapinoschema
narrow at base, broadening to widest at apex.
Species examined:
Pseudoclithria hirticeps
male,
P. mastersii
(Macleay, 1871)
female,
P. maura
(Janson, 1874)
male and female,
P. adusta
(Janson, 1889)
male,
P. dejecta
Lea, 1914
male,
P. erythroptera
Lea, 1914
male (from MNV image),
P. anchoralis
Lea, 1914
male and female,
P. rugosa
(Schaum, 1848)
male,
P. kershawi
Lea, 1914
male (from MNV image), seven undescribed
Pseudoclithria
species (C.H.M. & P.M.H., unpublished data),
Tapinoschema digglesii
(Janson, 1874)
male and female,
T. impar
(
Macleay, 1863
)
male and female,
T. lacunosa
(Janson, 1874)
male and female,
Octocollis setosus
Moeseneder & Hutchinson, 2012
male,
Grandaustralis boomerang
Hutchinson & Moeseneder, 2013
male and female.
Etymology
.
Navigator
males, in the species where males are known, have enlarged antennae that may have developed to such a size to assist them in locating females. Hence we chose a name for the genus that is descriptive of their searching behaviour. We assume that males, using their enlarged antennae, follow pheromones released by the females and navigate to the source.
Navigator
is the Latin noun for an entity that directs itself or a vessel over a planned course. The gender of
Navigator
is masculine.
Remarks
. We assign
Navigator
to the tribe
Schizorhinini
and, within it, to the subtribe Schizorhinina. In very old specimens of
N. fossor
and
N. ruficornis
there is a loss of metallic reflections on all surfaces and only the black or brown base colours are retained (compare
Figs. 6
and
9
).