Review of Cycadophila Xu, Tang & Skelley (Coleoptera: Erotylidae: Pharaxonothinae) inhabiting Cycas (Cycadaceae) in Asia, with descriptions of a new subgenus and thirteen new species
Author
Skelley, Paul
Author
Xu, Guang
Author
Tang, William
Author
Lindström, Anders J.
Author
Marler, Thomas
Author
Khuraijam, Jibankumar Singh
Author
Singh, Rita
Author
Rich, Stephen
text
Zootaxa
2017
4267
1
1
63
journal article
33061
10.5281/zenodo.575641
810b55e4-b8ba-4368-bf9c-8517ee33e7d0
1175-5326
575641
8920893E-E5F8-482A-A60D-7A248D2B0DCB
Cycadophila
(
Strobilophila
)
assamensis
Skelley, Xu & Tang
,
new species
Figs. 16
A–G
Adult diagnosis.
A member of
Cycadophila
(
Strobilophila
)
as discussed above, more readily distinguished by a combination of characters than any single unique character, and by analysis of the 16S rRNA mitochondrial gene.
Cycadophila assamensis
can be distinguished by the distally dilated protibia bearing narrowly spaced teeth along the apical third of the lateral margin, the distinct furrow on each side of pronotal base, elytral disc being mostly glabrous, the nearly straight basal pronotal margin, the lateral pronotal carina being abruptly curved inward at posterior angle pore which has a small acute projection behind it, and the terminal abdominal ventrite being sexually dimorphic (males with surface evenly coarsely punctate and setose; females with surface entirely setose and bearing a glossy area near the medial apex).
Adult description
. Length
4.69–5.19 mm
; width 1.8 8–2.00 mm. Body in dorsal view elongate, sides nearly straight, greatest width at middle of elytra; in lateral view convex dorsally. General body and appendage color solid reddish-brown [available specimens poorly preserved, darker; image of fresh specimen has color identical to
C. tansachai
]; dorsal surface distinctly punctate, surface appearing slightly dulled, dorsally appearing glabrous, with short procumbent hairs associated with punctation, ventrally mostly covered with short procumbent setae.
Head
in dorsal view conical, gradually narrowed apically, surface flat to slightly convex, distinctly punctured; width 1.00–
1.10 mm
; dorsal interocular distance
0.66–0.73 mm
, head width/dorsal interocular distance ratio 1.50– 1.52; ventral interocular distance
0.46–0.49 mm
, head width/ventral interocular distance ratio 2.16–2.25. Eye globular; bordered dorsally with supraocular stria; projected laterally, with large black facets and short, inconspicuous interfacetal setae. Frons with short, dark, subcuticular suture on each side, approximately 1/4 width of frons in length, extending obliquely to lateral margin above and anterior to antennal insertion. Antennal length about 2/3 pronotal width, and slightly longer than head width, antennomere relative lengths from base to end approximately 19:13:13:10:10:10:10:10:15:15:19; antennomere I (scape) fairly large, slightly elongate, antennomere II slightly smaller than III; IV–VIII small, width equals length; club fairly large, IX–XI similar in length, XI globular. Clypeus truncate anteriorly, anterior margin with long setae; densely punctate; somewhat emarginate, with narrow margin. Maxillary palpomeres II, III slightly longer than wide; IV elongate oval, apex densely papillate; relative lengths of II–IV approximately 3:3:5. Labium with mentum pentagonal with carina forming triangular plate projecting medially, lacking distinct lateral pockets; labial palpomere III elongate-oval.
Mentum
and submentum with moderate punctation and setation, setae short. Gular area smooth, without setae or punctation, except near suture with submentum where a shallow transversely elongate fovea is present bearing dense setose punctures, fovea dark brown.
Thorax
with pronotum transverse in dorsal view, with marginal beads on all sides; length/width ratio 0.65– 0.68, convex, evenly weakly arcuate most of length; anterior angles rounded; lateral carina with thickened bead, bead bearing scattered setose punctures; posterior angle exteriorly angulate, indented at pore; posterior margin projecting medially; with narrow, short longitudinal furrow posterolaterally, beginning at pore on posterior margin, extending forward and ending abruptly, length of furrows relative to pronotal length 0.22–0.24. Prosternum with anterior margin slightly emarginate, finely denticulate with fringe of long, anteriorly directed setae; posterior prosternal process round and convex. Hypomeron with coarse punctures laterally, medially with longitudinal striations. Scutellar shield transverse, posterior margin projected, pentagonal. Elytra elongate, nearly parallel sided, convex; length/width 3.28–3.65, greatest width near midlength; with marginal bead basally, striae not impressed, scutellary striole with 10–12 punctures; intervals of striae with distinct punctures. All elytral punctures bearing a single short seta; seta visible but barely emerging out of puncture. Punctation on meso- and metaventrite distinct.
Metaventrite long, convex laterally, slightly impressed medially, metathoracic discrimen extending about ¾ metaventrite length. Legs stout, similar in length; femora compressed laterally; tibiae shorter than femora, dilated to wide apex. Protibia triangularly dilated at apex, apex and apical 1/3 of lateral margin with stout spinules, marginal spinules separated by less than length. Meso- and metatibia less triangularly dilated.
FIGURE 16.
Photographs of
Cycadophila
(
Strobilophila
)
assamensis
, female holotype: A) dorsal habitus; B) ventral habitus; C) lateral habitus; D) head and prosternum, ventral; E) male genitalia; F) male paratype, abdominal ventrite V; G) female holotype, abdominal ventrite V.
Abdomen
with 5 ventrites bearing fine punctures; anterior margin with intercoxal process narrow, with triangular point anteromedially, lateral edges slightly projected, lateral and posterior margins arcuate, converging posteriorly; anterior and posterior margins of ventrites more or less straight or weakly bisinuate (
Figs. 16
F–G); ventrite I lacking subcoxal line, slightly longer medially than II; I–IV each with pair short hairs located adjacent to midline (often abraded); II–IV subequal in length; V slightly longer than IV with lateral margins converging posteriorly to a rounded apex bearing row of short appressed, densely arranged setae; ventrite V surface of male evenly coarsely and rugosely punctate, and entirely setose (similar to
C. tansachai
in
Fig. 19
F), female evenly setose, basally with coarse punctures, with small area of fine punctures and glossy surface near medial apex (
Fig. 16
G).
Male genitalia
(tegmen and median lobe of aedeagus) twisted approximately 45° toward the left side of animal and resting on side. Tegmen sclerotized, triangular, gently twisted; with anterior region ring-like, posterior region sheath-like, posterior margin slightly arcuate; lateral margins gradually converging posteriorly; dorsally with 2 large, elongate, somewhat coniform parameres. Parameres with long setae apically; length/width ratio 2.2 0. Aedeagus with median lobe short, slender, highly sclerotized, apex long and acuminate. Ratio of median lobe length to penile strut length 1:5.
Female
similar to male; except with pygidium truncate not as well developed; and dimorphic abdominal ventrite V surface as noted above.
Type
locality.
India
:
Assam
,
Kamrup
,
North Guwahati.
Range
.
India
(
Assam
,
Bihar
).
Material
examined.
Holotype
(by designation) female with the following labels: 1) [rectangular; white; printed in black ink] “
INDIA
:
Assam
,
Kamrup
,
North Guwahati
, ex
♂
cone
Cycas pectinata
, 2008
,
K. J. Singh
”; 2) [rectangular; pink; printed in bold black ink] “
PHOTO
”
.
3) [rectangular; white; printed in black ink] “collection date
June-July
2007”; 4) [rectangular; white; hand written in black ink] “
INDIA
:
ASSAM
,
Kamrup
,
North Guwahati
,
Cycas pectinata
, NG1”; 5) [rectangular; red; printed in black ink] “
HOLOTYPE
♂
Cycadophila assamensis
P. Skelley, G. Xu & W. Tang 2017
”.
Deposited
in the
FSCA
.
Allotype
male and
3
paratypes
: same data as holotype (
holotype
&
allotype
,
FSCA
, 1);
INDIA
:
Assam
,
Guwahati
IIT
Campus
, ex
♂
cone
Cycas pectinata
, 2008
,
K. J. Singh
(2).
Deposited
in the
FSCA
.
Others
examined:
One
additional adult male collected in association with larvae, currently considered this species:
INDIA
:
Bihar
,
West Champaran
, Valmiki Nat. Park,
Mar 2015
,
K. J. Singh
(1).
Deposited
in
FSCA
.
Etymology
. Named for the State where the
type
specimens were collected.
Remarks
. A female
holotype
was chosen because it was the most intact specimen available for study and because it shows the sexual dimorphism used to distinguish the species.
Cycadophila assamensis
is most similar to
C. tansachai
, differing most notably in abdominal sexual dimorphism.
Paucity of Indian materials prevents us from performing certain analyses and answering certain questions. Adult morphology allow us to distinguish the populations from
India
and propose a name for future research. Larvae from
Bihar
are also morphologically distinguishable from
C
. (
Strobilophila
) larvae collected in
Thailand
by the posteriad-tilting orientation of their t1 tubercle (see Key to larvae above) vs. the vertically oriented t1 turbercle in Thai specimens. While the
Assam
and
Bihar
populations are presented here as conspecific, we have doubts requiring further analyses. Thus, the
type
series is limited to the
Assam
population where we are able to make morphological comparisons with all known species. As noted above, molecular analyses failed with available material.
The host for this species in
Assam
,
Cycas pectinata
, occurs at atypically low elevations for the species (
52–192 m
; see
Singh & Singh 2014
) vs. over
500 m
for other localities of
Cycas pectinata
in the states of
Manipur
and
West Bengal
,
India
or in
Thailand
and provides evidence that this beetle is geographically isolated from other populations of the
Strobilophila
complex. See also remarks under
C. kwaiensis
.