Geoparnus rhinoceros sp. nov., a new edaphic dryopid with unusual ...

Zootaxa 1481: 59–68 (2007)
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Geoparnus rhinoceros sp. nov., a new edaphic dryopid with unusual sexual
dimorphism (Coleoptera: Dryopidae)
JÁN KODADA 1 , MANFRED A. JÄCH 2 , FEDOR ČIAMPOR JR. 3,4 & ZUZANA ČIAMPOROVÁ-
ZAØOVIČOVÁ 3
1
Department of Zoology, Faculty of Natural Sciences, Comenius University, Mlynská dolina B-1, SK-84215, Bratislava, Slovakia.
E-mail: kodada@fns.uniba.sk
2
Naturhistorisches Museum, 2. Zoologische Abteilung, Burgring 7, A-1014 Wien, Österreich. E-mail: manfred.jaech@nhm-wien.ac.at
3
Institute of Zoology, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84506, Bratislava, Slovakia. E-mail: f.ciampor@savba.sk,
zuzana.zatovicova@savba.sk
4
Corresponding author
Abstract
Adults of Geoparnus rhinoceros sp. nov. (Dryopidae) are described from Borneo (Sarawak, Malaysia). The male of the
new species possesses a distinct horn-like process on the clypeus, a character, which has so far not been reported from
Dryopidae. The type material was collected in primary rain forest by sifting forest floor debris. Analysis of variance of
metric characters was performed.
Key words: Coleoptera, Dryopidae, Geoparnus, new species, sexual dimorphism, Borneo, Sarawak, Malaysia
Introduction
Dryopidae with 32 described genera and 263 species represent a beetle family of relatively low diversity
(Kodada & Jäch 2005). Adults of most species occur in aquatic or riparian habitats, whereas a small percentage
is known to be terrestrial (edaphic or arboreal). The genus Geoparnus was established by Besuchet
(1978). The description was based on two males and one female of Geoparnus setifer Besuchet, sifted from
forest humus in the Cameron Highlands (peninsular Malaysia), and so far the genus includes only this single
species. Besuchet (1978) discussed the differences between Geoparnus and the edaphic Afrotropical
Oreoparnus Delève (1965), which he regarded to be its closest relative. Besides Geoparnus and Oreoparnus,
the following eight genera are supposed to be strictly edaphic: Sosteamorphus Hinton, Ghiselinius Perkins
and Momentum Perkins from the Neotropical Region (Hinton 1936, Perkins 1997), Parnida Broun from New
Zealand (Broun 1880), Drylichus Heller from New Caledonia (Heller 1916), Spalacosostea Kodada and Monstrosostea
Kodada & Boukal from the Oriental Region (Kodada 1996, Kodada & Boukal 2000), and Pedestrodryops
Kodada from South Africa (Kodada 2001).
Specimens of edaphic Dryopidae are rarely collected in large number and description of the new species is
in most cases based on few specimens. Fortunately, the species described herein is an exception since the type
material comprises 382 specimens, most of which were collected in 1994, by I. Löbl, D. Burckhard and the
first author. The material collected appeares to be sufficient to provide an analysis of size variability of the different
populations.
Accepted by P. Johnson: 16 Apr. 2007; published: 24 May 2007 59

Material, methods and abbreviations
The material used for this study is deposited in the following institutions (abbreviations are used to refer to
collections in the text): MHNG—Muséum d’Histoire Naturelle, Genève, Switzerland; NMW—Naturhistorisches
Museum Wien, Austria; SMNS —Staatliches Museum für Naturkunde, Stuttgart, Germany; CKB—
Collection of Ján Kodada, Bratislava, Slovakia.
Dried specimens used for structural studies were soaked in warm water to which several drops of concentrated
acetic acid were added, cleaned, and later exposed for several days in lactic acid. Specimens were
examined under a Wild M3Z stereomicroscope with Planapo 1.0 lens, by use of diffuse lighting at magnifications
up to 60 ×. Dissected male and female genitalia as well as the pregenital segments were studied as temporary
glycerin slides at magnifications up to 600 × under a Carl Zeiss microscope. All drawings were made
by using a drawing tube.
For scanning electron microscopy specimens were dehydrated in graded ethanol series and then air dried
from absolute ethanol, mounted on stubs with Tempfix, sputter coated with gold and viewed and photographed
in Jeol 840A.
Metric characters of 95 males and 94 females were measured with an ocular grid to the nearest 0.05 mm;
data in parentheses in the description below show mean ± standard deviation calculated from whole measured
material. One-way analysis of variance (ANOVA, Holm-Sidak test) or Kruskal-Wallis test were used to compare
metric variables of specimens from different localities and to find differences between them. Selected
metric characters were analysed separately for males and females respectively. Tests of assumptions for using
ANOVA (Kolmogorov-Smirnov Normality test) and subsequent pairwise multiple analyses were realized by
the use of the computer program SigmaStat 3.1 and values with P < 0.05 were considered significant. Sigma-
Plot 9.0 was used for drawing the box & whisker plots. Abbreviations for the measured characters used in the
text: BL— body length, length of pronotum and elytra measured along midline (retraction of head into prothorax
show variation within specimens and depends on the conservation, drying and preparation of specimens,
from this reason the length of head is omitted), EL—elytral length along suture, EW—maximum elytral
width, PL—pronotal length along middle, PW—maximum pronotal width.
Geoparnus rhinoceros sp. nov.
(Figs. 1–20)
Type locality: forest floor debris in primary rain forest, close to a tributary of River Sut, about 25 km east of
Kapit, Borneo, Sarawak, Malaysia.
Material examined: Holotype % (NMW): ”Sarawak (Borneo), ca 25 km E Kapit, 3. 1994, J. Kodada
leg.”. Paratypes 25 %%, 24 && (NMW, CKB): with the same locality data as holotype; 4 %%, 5 && (CKB):
"Sarawak (Borneo), Gunung Serapi, ca 19 km W Kuching, P. Bílek leg."; 2 && (CKB): "Sarawak (Borneo),
Gunung Serapi, ca 19 km W Kuching, primary forest, III. 1994, J. Kodada leg."; 106 %%, 97 && (MHNG): "E
Malaysia: Sarawak, 1994 Santubong, 32 km N Kuching, 0–100 m, 11.–15.V., no 1a, Burckhardt & Löbl leg.";
46 %%, 51 && (MHNG): "E- Malaysia: Sarawak, 1994, Gn. Gading, E slope, 50 m, 9 km E Lundu, 14.V., no
3a, Burckhardt & Löbl leg."; 8 %%, 6 && (SMNS): "Borneo: Sarawak, Belaga 14.–16. 3. 1990 leg. A.
RIEDEL"; 5 %%, 2 && (SMNS): "Borneo: Sarawak, Kuching, Santubong 26. 3. 1990 A. RIEDEL".
Diagnosis (adult strage): Geoparnus rhinoceros is a medium sized species (body length 1.7–2.5 mm),
unique among all known Dryopidae by the horn-like process on the head of the male. From Geoparnus setifer
it differs furthermore in the following most obvious characters: (a) body form ovoid, strongly convex, moderately
constricted between pronotum and elytra (G. setifer is elongate-ovate, less convex); (b) flat-bottomed
punctures on head and pronotum distinctly larger than a facet, shallowly impressed (in G. setifer these punc-
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KODADA ET AL.

tures are subequal to a diameter of a facet and deeply impressed); (c) scutellum concealed by elytra (in G. setifer
scutellum small but well visible in dorsal view); (d) shape of male genitalia.
Members of Geoparnus are characterized by combination of the following characters: (a) conspicuous
stiff setae with ridged surface and multifurcate apex; (b) short and compact body form and the antennal configuration.
Description: Habitus of male as in Fig. 1. Body form ovoid, moderately constricted between pronotum
and elytra, convex dorsally, very compact, strongly sclerotised; in males 1.54–1.92 (1.77±0.08) and in females
1.50–1.87 (1.72±0.08) times as long as wide (BL/EW); body length (BL): %%1.73–2.40 mm (2.04±0.13), &&
1.76–2.50 mm (2.08±0.13). Colour black, clypeus, antennae, mouthparts and legs paler yellowish or reddishbrown.
Immature specimens yellowish-brown.
FIGURE 1. Habitus of Geoparnus rhinoceros sp. nov., male.
NEW SPECIES OF GEOPARNUS (COLEOPTERA)
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FIGURES 2–9. Geoparnus rhinoceros sp. nov., 2) male head, dorsal view; 3) male head, lateral view; 4) pronotum, dorsal
view; 5) hypomeron and part of prosternum, ventral view; 6) prothorax, ventral view; 7) meso- and metathorax, ventral
view; 8) detail of flat-bottomed punctures with stiff setae, ventral view; 9) detail of stiff seta, lateral view.
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KODADA ET AL.

FIGURES 10–14. Geoparnus rhinoceros sp. nov.; 10) elytron, lateral view; 11) male protibia, lateral view; 12) abdomen
in male, ventral view; 13) fifth ventrite in male, ventral view; 14) fifth ventrite in female, ventral view.
Vestiture of body consists of several types of distinctly different setae: (a) short and longer hair-like setae
(Figs. 2, 4, 12), and (b) conspicuous stiff shorter and longer setae with ridged surface and multifurcate apex
(Figs. 8, 9); all setae yellowish. Short hair-like setae adpressed, confined mainly to clypeus, pronotum, epipleura
and ventral surface of thorax and abdomen, on elytra very scarce; longer hair-like setae concentrated
mainly on anterolateral portion of clypeus; all hair-like setae arising from small sockets. Conspicuous stiff
setae erect, arising either from large, flat-bottomed punctures (Figs. 2, 4, 7, 8, 12-14) on dorsal portion of
NEW SPECIES OF GEOPARNUS (COLEOPTERA)
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head, pronotum, meso- and metaventrite and partly on ventrites, or from small sockets on elytra, legs, pedicell,
central portion of ventrites and lateral parts of pronotum.
Head: Clypeus with fine punctures and fine reticulation; anterior margin produced dorsad forming a hornlike
process in male (Figs. 2, 3), arcuate and unproduced in female; surface around antennal insertion raised in
male, nearly flat in female; frons and vertex with flat-bottomed large punctures, punctures ca. 3–4 times as
wide as a diameter of a facet, punctures dense but distinctly separated from each other, interstices with fine
punctures and short setae. Compound eyes moderately protruding from head outline, small, with few setae.
Antennal insertion deep, scape short, pedicell enlarged, dorsally flat; antennal club moderately longer than
scape and pedicell combined, nine-segmented.
FIGURES 15–20. Geoparnus rhinoceros sp. nov.; 15 – 16) Aedeagus, ventral and lateral view; 17) ninth sternite in
male, ventral view; 18) ovipositor, lateral view; 19) eighth sternite in male, ventral view; 20) eighth sternite in female,
ventral view. Scale = 0.1 mm.
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FIGURES 21–22. 21) Box & Whisker plots showing the variability of body length of males at all localities; statistically
significant differences between two morphological forms were detected. Plots show medians (solid horizontal line),
means (dash lines), 25 th and 75 th percentiles (boxes), 10 th and 90 th percentiles (whisker extending from boxes), and 5 th and
95 th percentiles (outliers); 22) Box & Whisker plots showing the variability of body length/ elytral width ratio of males;
no distinct morphological forms were detected.
Thorax: Pronotal disc strongly convex; PL: %% 0.60–0.79 mm (0.70±0.05), && 0.50–0.76 mm
(0.68±0.05); PW: %% 0.97–1.40 mm (1.13±0.08), && 0.95–1.30 mm (1.15±0.07); lateral sides arcuate, crenulate;
anterior margin of pronotum straight; anterior corners deflected, short and acute, moderately protruding;
posterior margin bisinuate; posterior corners short; punctation similar to that on vertex but less dense.
Hypomeron widest posteriorly, with scattered larger punctures (Fig. 5); prosternum in front of coxae as long
as prosternal process, strongly punctate (Fig. 6); prosternal process longer than wide, lateral sides raised, apex
subacute, surface densely punctate. Meso- and metaventrite very short (Fig. 7), together shorter than prosternum,
mesal portion deeply impressed, lateral portions with large punctures, interstices with fine reticulation.
Elytra convex, without humeri; strongly declivitous laterally and posteriorly; lateral sides crenulate and visible
in dorsal view to posterior margin of mesocoxa; apices moderately produced, acute; each elytron with nine
rows of coarse, large, deeply impressed punctures, punctures about as coarse as those on pronotum but less
sharply delimited and not flat-bottomed, often somewhat subquadrate; interstices on central portion usually
less than half as wide as puncture diameter, laterally and posteriorly becoming narrower; intervals distinctly
narrower than punctures in rows, feebly raised, with rows of stiff erect setae; anterior margin arcuate; scutellum
concealed by elytra, inserted into cavity in sutural edge of each elytron. Epipleura anteriorly as wide as
maximum width of profemur, narrowed posteriad, effaced near fifth ventrite, inflected at level of metacoxa,
surface finely punctate. EL: %% 1.12–1.60 mm (1.33±0.11), && 1.15–1.70 mm (1.39±0.11); EW: %% 0.95–
1.30 mm (1.16±0.09), && 1.05–1.40 mm (1.21±0.09). Hind wings fully absent. Foreleg longest, moderately
shorter than body; middle and hind legs slightly shorter; protibia feebly longer than profemur, straight or
slightly bent and moderately thickened in both sexes (Fig. 11); meso- and metatibia similar in form but
shorter, with a small ventrodistal tooth in male; combined length of protarsomeres and claws moderately
exceeds half length of protibia; claws of foreleg in male wider than in female.
Abdominal intercoxal process (Fig. 12) moderately wider than prosternal process, apex subtruncate, lateral
sides raised; first ventrite in middle slightly longer than second and third ventrite together; fourth ventrite
about half as long as first one and nearly third as long as fifth ventrite; fifth ventrite more rounded and sides
less declivous in male than in female (Figs. 13, 14); surface of ventrites with large flat-bottomed punctures
and micropunctures, setose. Eighth sternite with short median process in male (Fig. 19) and long in female
(Fig. 20); ninth sternite narrow and long in male (Fig. 17).
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FIGURE 23. Known distribution of Geoparnus rhinoceros sp. nov. in Sarawak.
Aedeagus (Figs. 15, 16): phallobasis robust, subcylindrical, moderately curved, 1.5–1.8 times as long as
parameres, basally wider than apically (lateral view). Parameres moderately long, widest basally, gradually
curved ventrad and gradually narrowed toward apices; apices subtruncate in lateral view. Penis distinctly
shorter than parameres, widest basally, gradually narrowed apically; apex nearly acute (ventral view). Membranous
ventral sac with fine longitudinal furrows; fibula absent. Ovipositor (Fig. 18) distinctly longer than
abdomen; valvifer about 1.5–1.7 times as long as coxite; bursa copulatrix without sclerotised spinules.
Sexual dimorphism. Males with horn-like process on clypeus and tibial teeth, on average shorter, narrower
and less convex than females (see BL, EW in Tabs. 1, 2).
Habitat. Specimens were collected by sifting ground debris containing leaf litter, decaying twigs, remnants
of epiphytes, bark and other plant material accumulated mainly around large, living or dead trees. Most
specimens were found in primary lowland forest.
Distribution. The species is known from several localities in central and southwestern Sarawak (Fig. 23).
Etymology. Named in reference to the horn-like process on the male clypeus.
Variability. Analysis of variance showed significant differences among populations within all measured
characters (Tabs. 1, 2). The multiple comparison procedures revealed different results regarding sex.
TABLE 1. Variability of selected metric characters in males of Geoparnus rhinoceros with results of one way analysis of
variance (BL—body length, EL—elytral length along suture, EW—maximum elytral width, PL—pronotal length along
middle, PW—maximum pronotal width; first rows show ranges of measured values for specimens for different localities,
in second rows mean and standard deviation for the respective measurements, n—number of measured specimens, F—
Fisher`s value, H—the ANOVA on Ranks test statistics, P—probability).
Locality BL [mm] EL [mm] EW [mm] BL/EW PL [mm] PW [mm] PL/PW
Belaga 1.74–2.00 1.12–1.30 0.96–1.10 1.72–1.91 0.61–0.66 0.97–1.11 0.61–0.65
n = 9 1.852 ± 0.104 1.187 ± 0.077 1.034 ± 0.044 1.791 ± 0.061 0.659 ± 0.036 1.049 ± 0.043 0.628 ± 0.013
25 km E Kapit 1.76–2.07 1.12–1.30 1.00–1.14 1.73–1.90 0.64–0.76 0.97–1.12 0.62–0.72
n = 20 1.926 ± 0.075 1.236 ± 0.052 1.075 ± 0.041 1.792 ± 0.053 0.690 ± 0.029 1.051 ± 0.038 0.657 ± 0.023
Gunung Gading 1.95–2.40 1.30–1.60 1.10–1.30 1.54–1.92 0.60–0.75 1.05–1.40 0.48–0.64
n = 32 2.131 ± 0.105 1.445 ± 0.072 1.231 ± 0.061 1.733 ± 0.087 0.670 ± 0.045 1.180 ± 0.074 0.569 ± 0.041
Santubong 1.89–2.27 1.19–1.48 1.06–1.29 1.56–1.88 0.66–0.79 1.06–1.25 0.58–0.69
n = 31 2.072 ± 0.096 1.328 ± 0.069 1.168 ± 0.060 1.777 ± 0.087 0.744 ± 0.037 1.150 ± 0.054 0.648 ± 0.030
Gunung Serapi 1.99–2.19 1.28–1.43 1.11–1.17 1.80–1.88 0.71–0.76 1.08–1.17 0.66–0.67
n = 3 2.092 ± 0.102 1.344 ± 0.078 1.136 ± 0.030 1.840 ± 0.041 0.748 ± 0.029 1.131 ± 0.049 0.662 ± 0.005
F = 24.04 H = 61.17 H = 59.20 H = 13.11 H = 45.13 H = 46.79 H = 58.58
P < 0.001 P < 0.001 P < 0.001 P = 0.011 P < 0.001 P < 0.001 P < 0.001
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In males pairwise multiple comparison tests of body length (BL), elytral length (EL) and maximum elytral
width (EW) showed two morphological forms: (1) smaller and narrower males from central Sarawak
(Belaga, Kapit env.) and (2) larger and wider males from southwestern Sarawak near Kuching (Gunung Gading,
Santubong, Gunung Serapi). These groups are also evident from Box & Whisker plots of the data variability
(BL—Fig. 21; plots of EL and EW not shown). Pairwise multiple analyses of maximum pronotal width
(PW) and length (PL) suggest the same groups, with some exceptions: the conflicting comparisons always
included males from Gunung Serapi, which is likely caused by insufficient data from this locality (n=3). Subsequent
comparisons of the pooled data of both groups (using t-test) confirmed these two distinct morphological
forms—significant differences were found within all tested metric characters (BL, EL, EW, PW with
P

not confirmed. It must also be noted, that all specimens in each of the populations were collected together
from site of several square meters, and thus the differences could be due to idiosyncratic conditions of the
sample rather than to a geographic cline (i.e. the particular conditions of the development of the specimens in
the sample).
Except variations in metric characters, in a few specimens elytral punctures are irregularly arranged when
comparing left and right elytron and punctures are partly confluent.
Acknowledgements
Our sincere thanks are due to Ivan Löbl (MHNG) and Wolfgang Schawaller (SMNS) for providing the material
for this study. Special thanks are due to Jozef Stankovič (Comenius University, Bratislava) for his technical
assistance by electron microscopy and Willi Zelenka (Wien) for the habitus drawing of Geoparnus. Peter
Degma (Comenius University, Bratislava) is thanked for his help in statistical analyses. We are obliged to Ivan
Löbl for information about the habitat. Financial support was provided partly by the Slovak Scientific Grant
Agency, Project No. 1/3278/06.
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