sulawesi large-eyed onthophagus and their relatives: seven ... · 156 tijdschrift voor entomologie,...

IntroductionIn the ubiquitous scarab genus Onthophagus Latreille, 1802 the vast majority of species have eyes that are, when viewed full-face, narrowly exposed, in a usually bean-shaped to narrowly elliptic cephalic foramen. A minority, including species sometimes united in the subgenus Micronthophagus Balthasar, 1963 (first proposed in 1935), has larger, broadly elliptic, ante-riorly widely rounded eyes; their eyes then have more than the usual small number of facet rows across the widest point of the foramina (which means 12 or more), and the interocular distance is less than 5 times the maximum eye width (see the pictures in this paper). Although large-eyed Onthophagus occur East and West of the Indonesian island of Sulawesi (latest reviews: Krikken & Huijbregts 1987, for Sun-daland; Balthasar 1969, Matthews 1972, for Austral-asia), they were thus far not yet recorded from the island proper. In this paper six new large-eyed spe-cies are described from mainland Sulawesi, all col-lected on the island during Project Wallace 1985 and

follow-up activities. Their descriptions are preceded by a key. Additional exploration, particularly in upland situations, will doubtless result in the discov-ery of further large-eyed taxa. Most large-eyed spe-cies are rare in collections, indicating that, nocturnal or crepuscular habits aside, there may be more to their ecology than suggested by the straightforward collection event data on the labels.

As is the case with their analogues elsewhere in the Oriental and Australasian Regions (Krikken & Huijbregts 1987), the Sulawesi large-eyed Onthopha-gus are an amalgam of different taxonomic groups; in phylogenetic terms: they are a polyphyletic assem-blage – the character state of having broad eyes is not autapomorphic, judged from a larger character set drawn from numerous Oriental-Australasian Onthophagus. In the Sulawesi fauna we recognize here four groups of large-eyed species, one includ-ing a remarkable pair of closely related new spe-cies belonging to a group near or in the subgenus

Sulawesi large-eyed Onthophagus and their relatives: seven new species, with a key (Coleoptera: Scarabaeidae: Scarabaeinae)

J. Krikken & J. Huijbregts

Seven new species of the scarab genus Onthophagus Latreille, 1802 from Sulawesi (Indonesia) are keyed, described, and illustrated. Six of them are characterized by unusually large ocular foramina. Although large-eyed species have been reported from adjacent regions, these are the first records for Sulawesi. The new species are: Onthophagus mogo, O. sinagai, O. vanofwegeni, O. vanasseni, O. vanderblomi, and O. watuwila. Four groups of species are recognized. The artificial nature of the subgeneric concept Micronthophagus Balthasar, 1963, frequently used to accommodate large-eyed Onthophagus species, is exemplified by a very close relative of vanderblomi, the narrow-eyed new Sulawesi species O. sembeli, here also described. This species pair is tentatively allocated to Boucomont’s (1914) O. variolaris group; the position of this group is discussed in relation to the essentially Oriental subgenus Indachorius Balthasar, 1941. J. Krikken & J. Huijbregts, National Museum of Natural History Naturalis, Postbus 9517, 2300 RA Leiden, Netherlands. [email protected]

Tijdschrift voor Entomologie 151: 155–171, Figs. 1– 54. [ISSN 0040–7496]. http://www.nev.nl/tve© 2008 Nederlandse Entomologische Vereniging. Published 1 December 2008.

156 Tijdschrift voor Entomologie, volume 151, 2008

Indachorius Balthasar, 1941, i.e. a large-eyed and a narrow-eyed species. They were both found on the same sites. Like in Sundaland, whence we also know related narrow-eyed and large-eyed species, the joint occurrence of these two so evidently close forms on Sulawesi shows once again the current inadequacy of the Micronthophagus and Indachorius concepts (Balthasar 1963 was already aware of this). The new narrow-eyed Sulawesi species is described in this paper along with its large-eyed relative, and included in the key and the species list. One of the characters used to distinguish Indachorius is the reduction of the proximal protibial denticle in the usual set of four. A large-eyed Sulawesi species in the so-called O. vanasseni group defined below, however, as well as certain large-eyed species from Sundaland, also may have three instead of four larger protibial denticles; even the type-species of Micron- thophagus (O. hystrix Boucomont, 1914, western part of Oriental Region) has three denticles. Instead of formally referring our two Indachorius-like spe-cies to a subgenus, we prefer, for the time being, to follow Boucomont’s (1914) practice, referring them to the variolaris group (his group 18, O. variolaris Lansberge, 1885 from Sundaland given as type). The species included are all small, plump, have very long tarsi, and the protrusions on their frontovertex are low; they all have very abundant, erect, long, deciduous hairs, and their propectoral sides have a ridge curving from the coxal side to the anterolateral angle, not to the lateral side. With a redefinition of the subgenus, Balthasar (1963) could have placed the species of the variolaris group in his Indachorius, but instead they have ended up in different sub-keys. Sundaland has numerous undescribed species in this group, and there may be more on Sulawesi – note also the imperfectly understood variability of the Sulawesi species. Clearly, we will have to return to the taxonomy of the variolaris group in due course.The members of the Sulawesi O. vanasseni group, while not having anything to do with the pair in the variolaris group, may indeed be related to cer-tain Sundaland large-eyed forms treated previously (Krikken & Huijbregts l.c.) – further research will have to confirm this; at any rate, the diagnostic remarks below implicitly separate the Sulawesi species from their Sundaland relatives. The single Sulawesi member of the drescheri group definitely looks like some species from Sundaland, and is also diagnosed with these relatives in mind. The single member of the watuwila group reminds of Australasian forms – further research on large-eyed Onthophagus from the area East of Sulawesi is under way to check up on any relatives in our material from the region.

Technical remarksThe primary purpose of this paper is the straight-forward morphological description and diagnosis of the taxonomic diversity of the large-eyed Sulawesi Onthophagus. It is part of a series presenting results from field campaigns in Southeast Asia. The speci-mens available were mostly collected by deploying pitfall traps baited with human faeces or fish. Light and flight interception traps were also operated dur-ing the campaigns on Sulawesi; the combi-trap men-tioned is a combination of a Malaise trap and a flight interception trap in one (our specimens were taken from the bottom container). At present the material recorded in this paper is kept in Leiden.

As illustrations are considered more useful than abstract text, enlarged photographic excisions of five body parts are depicted for each species, habitus pictures aside: contours of head (full-face), prono-tum and left elytron (dorsal), protibia and metatibia, and, of course, where applicable, parameres (differ-ent views). It is believed that such illustrations give more information than outline drawings. Sexually dimorphic pronota of some species are illustrated for male as well as female. The term full-face view is applied where the surface of the element concerned is maximally parallel to the plane of the picture (like the head); some elements slightly tilted. Refer to descriptions for holotype measurements instead of scale bars.The qualification abundant for microsculptural units (like punctures) usually means: separated by 2-5 diameters, dense: 1-2 diameters, crowded: less than 1 diameter; sparse: means separated by at least 5 diameters. The type of punctation is qualified only if it is decidedly different from simple punctation. The prefix micro- usually refers to sculpture and pilosity distinct at magnifications x40 and higher. Usually types of punctures are only qualified if dis-tinctly different from a simple punctation; (sub)ocellate here means that a (usually isodiametric) well-defined puncture has some sort of shallow interior pit. Where two different size classes of punctures are present on a particular element the smaller is termed secondary. Conventional terminology is applied. The term pro-pectus stands for the total underside of the protho-rax. The external dentation of the protibia usually consists of three larger distal and one slightly smaller proximal denticle (3+1 in the descriptions), plus what is here termed proximal serration, i.e. a variably extensive series of small, usually equal-sized teeth; as indicated in the introduction, some of our species have their proximal external denticle fully reduced (sunk into the proximal serration).

157Krikken & Huijbregts: Sulawesi large-eyed Onthophagus

Characters listed in the paragraphs Diagnosis are in estimated order of importance. Always beware of intraspecific differences between major males, minor males, and females. They may have very different cephalic and/or pronotal protrusions; leg charac-ters may also be different. The material available is limited, and, consequently, intraspecific variation is insufficiently known. The male sex in Onthophagus is usually recognizable from the foreshortened abdomi-nal sternites (particularly the anal sternite). New spe-cies are based on females only if assumed very differ-ent from their relatives (one species in this paper is based on a female with a very different microsculp-ture from the other species). Note that the longer pilosity characteristic of five of the seven species is deciduous. With the exception of one species (watuwila group), the parameres of the species are rather simply built, being curved, tapering, lacking taxonomically very useful details; even so they are illustrated for the six species with known males. Full-face here means that the plane of the picture cuts the parameral tips and (median) base. Where ranges in numbers and measurements are given, this may be an expression of both estimated deviation in observations and actual variation; one should not pretend precision where this cannot be achieved.The # symbol in the Material examined text indicates any sample codes as given on the specimen label.RMNH = National Museum of Natural History Naturalis, Leiden

Key to large-eyed Sulawesi Onthophagus species and a narrow-eyed relative The holotype descriptions further below are followed by diagnoses, which should be checked in addition to using the key characters.

Important characters • dorsal punctation and associated pilosity (distri-

bution, densities, punctural diameter, length of setae)

• colours (particularly of dorsum)• background microsculpture and consequent

light reflection of various elements• shape of clypeal apex and clypeogenal border• head ornamentation (transverse ridges, pair of

horns/tubercles between eyes, vertexal ridge etc.)• shape, including proportions and distance, of eye

foramina• shape of intercoxal part of metasternum• pronotal ornamentation (presence and develop-

ment of protrusion on midline)

• pronotal outline (dorsal and full-face view of posterolateral border)

• curvature of ridge delimiting postocular surface on propectus

• protibial dentation (development of external denticles and proximal serration)

• development of protibial apex (shape of apico-internal edge, presence of protrusion and/or setae)

• length proportions terminal spur and tarsal seg-ments of metatibia

• aedeagal shape (complex vs simple, details)

Key1. Head with pair of upright horns between

eyes and short (occasionally effaced) trans-verse ridge on clypeofrontal transition. En-tire dorsum glabrous. Pronotal disc evenly convex. Pygidium matt (microreticulate), with minute, sparse punctures. Parameres relatively complex (tip broad). (watuwila group) . . . . . . . . . . . . . . . . . . . . . . . . . . . . watuwila

– Head without pair of horns. Elytra (with one exception, see mogo) with long setae, at least on lateral declivity. Parameres simply curved, tapering (tip may be spatuliform). Male of one species unknown . . . . . . . . . . . . . . . . . . . . . . . 2

2. Propectoral sides with ridge curved from coxa to anterolateral angle. Protibia of male usually with three larger external denticles. Small species, with pronotal surface evenly, rather strongly convex. Clypeofrontal tran-sition with low transverse ridge. Pronotum and elytra generally strongly punctate, with very long, more or less erect, pale setae; shiny between punctures. Metatarsal segment 1 much longer than terminal spur, also long-er than segments 2-5 combined (variolaris group) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

– Propectoral sides with ridge running from coxa to lateral margin. Protibia of male usu-ally with four (in one species with three) external denticles. Larger species, at least males with isolated protrusion(s) on pronotal midline, pronotal disc more finely punctate. Metatarsal segment 1 about as long as termi-nal spur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

3. Pronotum and elytra matt, at least elytral sides with long setae. Pronotum with vari-ably developed projection on midline. Poste-rior section of lateral pronotal border strong-ly converging to base. Clypeofrontal ridge absent (certainly in males). Vertex with ridge between eye bases (vanasseni group) . . . . . . . . . 4

– Pronotum and elytra shining, completely


glabrous (×10). Pronotum evenly slightly convex. Posterior section of lateral pronotal border nearly parallel-sided. Clypeofrontal ridge feeble, straight, not reaching clypeoge-nal suture. Frontovertex without any ridges between eyes. Based on female! (drescheri group) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . mogo

4. Elytral interstriae all with numerous long se-tae. Anterior lobe of metasternum (between mesocoxae) with pit. Protibia of at least ma-jor males with 3 external denticles . . . vanasseni

– Interstriae of elytral disc incompletely setose, or glabrous. Anterior lobe of metasternum without pit. Protibia with 3+1 external den-ticles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

5. Only shiny elytral interstria 8 with numer-ous setae, some on 7, and on apex. Pronotum only posterolaterally with few (less than 10) setae (or glabrous). Interstrial punctation of elytra much finer . . . . . . . . . . . . . . . . vanofwegeni

– Elytral interstriae 1, 5-8 and apex of others with numerous setae, all interstriae matt. Pronotum laterally with numerous (more than 30) setae. Interstrial punctation much coarser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . sinagai

6. Eye foramina very broad (interocular dis-tance 2-3× eye width) . . . . . . . . . . . . vanderblomi

– Eye foramina narrow (interocular distance ca 8× eye width) . . . . . . . . . . . . . . . . . . . . . . . . sembeli

List of large-eyed Sulawesi Onthophagus species and a narrow-eyed relativeWith indication of some guiding group characters between parentheses.

(a) drescheri group (dorsum glabrous, shining, pro-trusions on head obsolescent, pronotum evenly convex)

mogo sp.n. – N Sulawesi

(b) vanasseni group (pronotum with protrusion on midline, dorsum variably setose, largely matt)

sinagai sp.n. – N Sulawesi vanasseni sp.n. – C Sulawesi vanofwegeni sp.n. – N Sulawesi

(c) variolaris group (propectoral ridge running to an-terolateral angle, setose all over)

vanderblomi sp.n. – E, SE Sulawesi (large-eyed) sembeli sp.n. – N, E, SE Sulawesi (narrow-eyed)

(d) watuwila group (pair of interocular protrusions present, dorsum glabrous, 4 large protibial den-ticles present)

watuwila sp.n. – SE Sulawesi

Species accounts

Onthophagus drescheri group

Onthophagus mogo Krikken & Huijbregts, sp.n.Figs 1, 11-15

Material examined. Holotype female only (RMNH), with the following label data: Indonesia: N Sulawesi: Dumoga Bone NP: Mt Mogogonipa, alt. 1000 m, 23-26/08/1985, J. Huijbregts, #HH431, multist-ratal evergreen forest, 2 rat excrement traps.

Female (holotype). Body length ca 5.8 mm. Colour yellow-brown, largely shining. Pilosity pale-yellow, sparse, dorsal side glabrous. Clypeal margin slightly reflexed, anteromedially emarginate; border at clypeogenal transition virtu-ally continuous; clypeofrontal ridge placed in front of eyes, feeble, straight, not reaching clypeogenal sutures; clypeal surface finely, densely rugulate, fron-tovertex with sparse, ill-defined punctures and with microreticulation, surface sericeous; genal border widely rounded, surface with numerous scattered punctures. Vertex unmodified. Eyes very large, can-thus incomplete, border widely rounded in front; ca 20 facet rows across widest point. Ratio interocular distance / maximum (transverse, single) eye width ca 2.5Pronotum with evenly, moderately convex general surface, without discal midline impression, in dor-sal outline somewhat parallel-sided; anterior sec-tion of lateral border slightly rounded, anterolateral angle shortly rounded, ca 95º; posterior section of lateral border moderately sinuate, posterolateral angle obtuse; anterior and lateral borders margin-ate; base virtually immarginate; entire pronotal derm with abundant, fine punctation; density on disc 40-50/0.25 sq.mm, diameters 0.03-0.05 mm; sec-ondary punctation very sparse. Elytral striae discally well-defined, with distinct punctures, mostly separated by 3-5 times their diam-eter, slightly crenulating interstriae; interstriae very slightly convex, with sparse, fine punctures, and with microreticulation, but shining nonetheless; epipleura with microsetae.Antennal club grayish-brown. Propectoral side annulate to hemipunctate-setose, with ridge from


coxa running to lateral margin. Metasternum slightly raised (tectiform) in front, disc with sparse, with fine punctation and microreticulation, anterior surface and lateral wings with sparse (partly seta-bearing) subocellate punctures. Mesosternum and mesepi-mera similarly punctate, matt. Anteanal abdomi-nal sternites each with transverse row of annulate punctures along base; anal sternite with numerous fine, scattered punctures. Pygidium with abundant, fine, scattered punctures, and with microreticula-tion; base marginate, apex broadly marginate. Protibia with 3+1 larger denticles, terminal one sharply acuminate, proximal one small, blunt; proximal-external serration fine, distinct (7-8 small teeth); terminal spur elongate-acuminate, curved; apico-internal angle obtuse. Protarsus long, slen-der. Meso- and metatibiae elongate-triangular, with slightly developed external fossorial elevations, apical crest subelliptic, with fringe of long spines. Meso- and metatibial terminal spurs unmodified, long, acuminate. Profemoral underside sparsely punctate-setose; undersides of other femora with very few seta- bearing fine punctures. Segment 1 of metatarsus shorter than segments 2-5 combined; approximate length proportions metatibial spur // metatarsal segments 1-5 27//27/13/7/5/10.Measurements in mm. Maximum width of head 1.9. Median length of pronotum 2.0, maximum width 3.0. Sutural length of elytra 2.9, maximum width combined 3.4.

Variation and sexual dimorphism. Species known from female holotype only.

Diagnosis. Although based on a single female, O. mogo is likely to be easily recognizable in the set of large-eyed Sulawesi species now known. It is very shining, sparsely setose, the dorsum being entirely glabrous. Dorsal outline of pronotum somewhat parallel-sided. Clypeofrontal ridge straight, very low. Colour yellow, not making an immature impression though. Frontovertex matt, without protrusions. Protibia with 4 external denticles, and distinct, fine proximal serration. Eyes very large, their border widely rounded in front. Ridge running from pro-coxa to prothoracic side distinct. O. mogo reminds of drescheri Paulian, 1939 and its relatives, a group of species occurring in Sundaland, but the combination of features listed above should distinguish mogo from the other group members.

Derivation of species name. Named after the type locality, an isolated coastal mountain, near Dumoga Bone NP in North Sulawesi.

Onthophagus vanasseni group

Onthophagus sinagai Krikken & Huijbregts, sp.n.Figs 2, 8, 16-21, 49

Material examined. Holotype male (RMNH), with the following label data: Indonesia: N Sulawesi: Dumoga Bone NP: between Edwards Subcamp- Clarke’s Subcamp, 1200m, 10/03/1985, I Hanski Transect 62, lower montane rainforest. Paratypes. Male and female paratype from Dumoga Bone NP, T60, 1985, no further details.

Male (holotype). Body length ca 7.5 mm. Colour red-dish-brown, forebody darker than most other parts, largely matt. Pilosity pale-yellow, very long on ven-tral side and legs; pronotal sides and elytra (except disc) with numerous long, erect setae. Clypeal border widely evenly, rounded; margin reflexed, upright, apex produced into short subtri-angular lobe; clypeogenal transition vaguely inter-rupted at border, clypeogenal suture vaguely distinct, slightly curved, ending at ocular protrusion; lateral tip of gena shifted posteriorly, shortly rounded, genal surface with numerous fine punctures; clypeofrontal ridge absent; clypeal surface finely densely punctate, slightly transversely rugulate, anteromedian part smooth. Frons with pair of juxta-ocular, indistinct, very low, pyramid-like elevations; frons behind these elevations sparsely, finely punctate, and microreticu-late. Vertex posteriorly delimited by distinct curvilin-ear ridge between eye bases. Eyes very large, canthus complete, border widely rounded in front; 25-27 facet rows across widest point. Ratio interocular distance / maximum (transverse, single) eye width ca 2.6.Pronotum with moderately convex general surface, anteromedially deplanate; anterior section of lateral border straight, anterolateral angle shortly rounded, ca 95º; posterior section of lateral border slightly sin-uate, posterolateral angle rounded; anterior and lat-eral borders marginate; base widely rounded, virtu-ally immarginate; basomedian surface with strongly reflexed, anteriorly directed, tapering horn; horn with shortly rounded apex, in lateral view evenly curved; pronotal base adjacent to base of horn with shallow depression on either side; pronotum discally with sparse, fine punctures, laterally with abundant, coarse, well-defined seta-bearing subocellate punc-tures; entire pronotal derm with microreticulation; density of punctation on disc 20-30/0.25 sq.mm, diameters 0.05-0.06 mm. Elytra uniformly yellow-brown; striae well-defined, subparallel, 7 simply, slightly curved near humeral


umbone; strial punctures distinct, mostly separated by 3-6 times their diameter, slightly crenulating interstriae; interstriae almost flat, with sparse, fine punctures, lateral and distal surface with abundant to dense, larger, microgranulate seta-bearing punc-tures; entire surface with microreticulation; epipleu-ron punctate-setose.Antennal club pale-yellow. Propectus with ridge run-ning from procoxa to lateral margin. Mesosternum and adjacent mesothoracic parts finely, crowdedly punctate-setose, matt. Metasternum with glabrous midline, disc and sides abundantly punctate-setose, lateral wings with abundant, well-defined, matt, seta-bearing subocellate punctures; general microreticula-tion of surface vague. Abdominal sternites microre-ticulate, along base each with rows of seta-bearing punctures, on medial surface punctation more or less effaced; most setae very long. Pygidium slightly con-vex, with abundant, well-defined, subocellate seta-bearing punctures, and with microreticulation, matt;

base marginate, apex narrowly marginate. Protibia with 3+1 larger external denticles sepa-rated by distinct serration, and with proximal ser-ration (6-8 small teeth); terminal spur very slender, elongate-acuminate, curved; apico-internal angle rounded-obtuse, not penicillate. Protarsus long, slen-der. Meso- and metatibiae strongly dilated distad; mesotibia slightly sinuate; all with slight external fos-sorial elevations, apical crest subelliptic, with fringe of spines; spurs slender, elongate-acuminate. Femo-ral undersides abundantly punctate-setose. Segment 1 of metatarsus shorter than segments 2-5 combined; approximate length proportions metatibial spur // metatarsal segments 1-5 34//35/15/9/5/16.Parameres simple, fig. 49 (poorly sclerotized).Measurements in mm. Maximum width of head 2.3. Median length of pronotum 2.5, maximum width 3.8. Sutural length of elytra 3.3, maximum width combined 4.2.

Figs 1-10. Onthophagus, 1-7, habitus, oblique, 8-10, pronotal protrusion in profile. 1, mogo, female holotype; 2, 8, sinagai, male holotype; 3, 9, vanofwegeni, male; holotype; 4, vanasseni, male holotype, 10, minor male para-type; 5, vanderblomi, male holotype; 6, sembeli, male holotype; 7, watuwila, male holotype.

10987

654

321


Figs 11-21. Onthophagus, body part contours. 11-15, mogo, female holotype. 16-17, 19-21, sinagai, male holotype, 18, female paratype. 11, 16, head, full-face; 12, 17, 18, pronotum, dorsal; 13, 19, left elytron, dorsal; 14, 20, pro-tibia, upper side; 15, 21, metatibia, underside.

11

12

13

14

15

16

17

18

19

20

21


Variation and sexual dimorphism. Body length 6-7.5 mm. Minor male in lateral view with triangular ele-vation on pronotal midline. Female and minor male with variably developed, medially more or less inter-rupted interocular ridge; clypeal surface more dis-tinctly rugulate-punctate. Brown colour varies, from dark to light, but forebody always darker. Clypeal apex not at all expanded-reflexed, as in holotype.

Diagnosis. O. sinagai is primarily distinguished from the closely related vanofwegeni by the distribution of its dorsal pilosity and certain microsculptural details. Sides of pronotum and elytra (including apical half of interstria 1) with numerous long setae in dense, coarse punctation. Pronotal midline with elongate protrusion, in major male with long projection, curved from base forward and downward, in minor male and female with angular protrusion placed at ca 0.4 from anterior border. Protibia with four exter-nal denticles and extensive, equal-sized proximal serration. Body largely matt, due to microreticula-tion. Head of male without clypeofrontal ridge, with medially more or less interrupted interocular ridge. Body yellow-brown, forebody distinctly darker brown. Eyes very large, their border widely curved in front. Ridge from procoxa running to prothoracic side distinct. Vertexal plate posteriorly defined by arcuate ridge. Parameres relatively simple, curved (lateral view), tapering.

Derivation of species name. Dedicated to Walman Sinaga, Indonesian conservationist, who, within the Directorate General of Forestry, has been instru-mental to the development of Indonesia’s National Parks.

Onthophagus vanofwegeni Krikken & Huijbregts, sp.n.Figs 3, 22-27, 50

Material examined. Holotype male (RMNH), with the following label data: Indonesia: N Sulawesi: Dumoga Bone NP: Mt Ambang: Danau, 27/01/1985, I Hanski. Paratypes. 2 female paratypes with same data as holotype; 1 female paratype from same mountain in N Sulawesi: Mt Ambang NR, 20 km E Kota-mobagu, alt. 1230 m, 10-13/09/1985, J. Huijbregts, #HH448A, multistratal evergreen forest, 2 human excrement traps. Male (holotype). Body length ca 6.8 mm. Colour red-dish-brown, largely matt, forebody darker than most other parts. Pilosity pale-yellow, pronotal sides and elytra (except disc) with long, erect setae. Clypeal border evenly rounded, margin slightly

reflexed, apex slightly produced; clypeogenal tran-sition virtually continuous at border, suture vague; gena with rounded lateral tip, surface abundantly, finely punctate, and microreticulate; clypeofron-tal ridge absent; clypeal surface finely transversely rugulate-punctate, frons with laterally slightly arcu-ate, medially straight and lowered interocular ridge; frons behind this elevation very sparsely, finely punc-tate, and microreticulate. Vertex posteriorly with dis-tinct, low, curvilinear ridge between eye bases. Eyes very large, canthus complete, 19-22 facet rows across widest point. Ratio interocular distance / maximum (transverse, single) eye width ca 3.0.Pronotum with moderately convex general surface, anteromedially slightly deplanate; anterior section of lateral border virtually straight, anterolateral angle shortly rounded, ca 95º; posterior section of lateral border slightly sinuate, posterolateral angle rounded; anterior and lateral borders marginate, base widely rounded, virtually immarginate; central part of pronotum with short, triangular, anteriorly directed, projection, triangular in lateral view; pro-notal disc adjacent to base of elevation with shallow depression on either side; pronotum laterally with numerous, evenly distributed ocellate punctures, separated by 2-3 diameters, their diameters strongly decreasing toward disc; entire pronotal surface with microreticulation; posterolateral margin with a few coarse punctures bearing long seta; density of punc-tation on disc 35-45/0.25 sq.mm, diameters 0.02- 0.03 mm. Elytral striae discally well-defined, with distinct punctures, mostly separated by 3-6 times their diam-eter, slightly crenulating interstriae; stria 1 and its punctures more distinctly impressed; interstriae flat, with sparse, very fine punctures, interstria 8 and ely-tral apex with abundant to dense, larger seta-bearing punctures; surface of interstriae with microreticula-tion (matt), of interstria 8 shiny.Antennal club pale-yellow. Propectus with ridge run-ning from procoxa to lateral margin. Mesosternum crowdedly, finely punctate-setose, matt. Metaster-num with glabrous, impunctate midline, slightly transversely convex in front; disc largely abundantly punctate(-setose), lateral wings of metasternum and adjacent lateral parts with abundant, seta-bearing, subocellate, matt punctures; microreticulation indis-tinct. Abdominal sternites each with seta-bearing subocellate punctures along base, setae very long. Pygidium almost flat, with abundant, seta-bearing subocellate punctures, and with microreticulation; base marginate, apex narrowly marginate.Protibia with 3+1 larger denticles separated by some serration, proximal serration limited (4-5 small teeth); terminal spur elongate-acuminate, curved


(tip broken off ); apico-internal angle rounded-obtuse, not penicillate. Protarsus long, slender. Mesotibia slender, slightly sinuate, strongly dilated distad, apical crest subelliptic, with fringe of spines; metatibiae straight, strongly dilated distad, api-cal crest subelliptic, somewhat sinuate, with fringe of spines; spurs unmodified, elongate-acuminate; meso- and metatibiae with slightly developed exter-nal fossorial elevations. Femoral undersides all sparsely punctate- setose. Segment 1 of metatarsus shorter than segments 2-5 combined; approximate length proportions metatibial spur // metatarsal seg-ments 1-5 [24]//35/15/9/6/15 (tip of spur broken off; length equals segment 1 in other specimens).Parameres simple, fig. 50.Measurements in mm. Maximum width of head 2.2. Median length of pronotum 2.3, maximum width 3.6. Sutural length of elytra 3.3, maximum width combined 4.0.

Variation and sexual dimorphism. Body length 6.5-8.5 mm. The holotype may well be a minor male. Both sexes with forward projection on pronotal mid-line. A large female has a long, semierect, anteriorly directed, tapering pronotal horn and its pygidium is more convex. The others have a horn similar to the holotype.

Diagnosis. O. vanofwegeni is primarily distinguished from the closely related sinagai by the distribution of its pilosity and certain microsculptural details. Dorsal pilosity limited, on elytra only abundant on shiny, yet rather densely, coarsely punctate interstria 8, disc glabrous. Most of body surface matt, due to microreticulation. Head without clypeofrontal ridge, with medially more or less interrupted interocular ridge. Reddish-brown, forebody darker than rest. Pronotum on posterior half of midline with ante-riorly directed, slender projection; variation of this character to be established; anterior declivity more or less deplanate. Protibia with four distinct external denticles and limited proximal serration. Eyes very large, their border widely rounded in front. Ridge from procoxa running to prothoracic side distinct. Vertexal plate posteriorly defined by arcuate ridge. Parameres relatively simple (lateral view), curved, tapering.

Derivation of species name. Dedicated to our col-league Leen van Ofwegen (Leiden, The Nether-lands), a soft coral expert, who cheered us up during boring description sessions.

Onthophagus vanasseni Krikken & Huijbregts, sp.n.Figs 4, 9-10, 28-33, 51

Material examined. Holotype male (RMNH) with the following label data: Indonesia: C Sulawesi: Lore Lindu NP: Danau Tambing forest, alt. 1600 m, 05-09/12/1985, J. Krikken, #pw51a, multistratal evergreen forest, 4 human excrement traps. 4 female paratypes with same data. Paratypes. 1 male paratype from same region: Palu District: Tawaeli-Tomboli rd (km34), alt. 500 m, 20-22/12/1985, J. Krikken, #pw69a, multistratal evergreen forest (degraded), 2 human excrement traps.

Male (holotype). Body length ca 8.3 mm. Colour reddish-brown, largely matt, forebody darker than most other parts. Pilosity pale-yellow, pronotum and elytra with numerous long, erect setae. Clypeal margin reflexed, apex produced into short, upright subtriangular lobe; border at clypeogenal transition slightly interrupted; genal tip shortly rounded, surface with dense, scattered punctures; clypeofrontal ridge absent; clypeal surface trans-versely rugulate-punctate; frons between eyes with transverse ridge medially obliterated, shortly curved on either side near eye; frons behind this ridge nearly impunctate, surface microreticulate. Vertex poste-riorly with distinct curvilinear ridge between eye bases. Eyes very large, canthus complete, 18-22 facet rows across widest point. Ratio interocular distance / maximum (transverse, single) eye width ca 3.6.Pronotum with moderately convex general surface, anteromedian part slightly deplanate; anterior sec-tion of lateral border straight, anterolateral angle shortly rounded, ca 90º; posterior section of lateral border straight, posterolateral angle very obtuse; anterior and lateral borders marginate; base widely rounded, virtually immarginate; pronotal base with anteriorly directed, strongly tapering, dorso-ventrally complanate, apically subacute, in lateral view evenly curved horn; pronotal surface at base of horn on either side shallowly depressed; pronotal surface lat-erally with abundant, seta-bearing subocellate punc-tures, size and density and length of setae increasing laterad; entire pronotal surface with microreticula-tion; density of punctation halfway lateral declivity 20-25/0.25 sq.mm, diameters ca 0.05 mm. Elytral striae discally well-defined, with distinct punc-tures, mostly separated by 3-6 times their diameter, scarcely crenulating interstriae; interstriae almost flat, with (locally 2 rows of ) seta-bearing microgranulate punctures, punctures on lateral interstriae coarser; entire surface with microreticulation.


Figs 22-33. Onthophagus, body part contours. 22-26, vanofwegeni, male holotype, 27, female paratype; 28-32, vanasseni, male holotype, 33, female paratype. 22, 28, head, full-face; 23, 27, 29, 33, pronotum, dorsal; 24, 30, left elytron, dorsal; 25, 31, protibia, upper side; 26, 32, metatibia, underside.

24

23

22 25

26

27

28

29

30 31

32

33


Figs 34-43. Onthophagus, body part contours. 34-38, vanderblomi, male holotype; 39-43, sembeli, male holo-type. 34, 39, head, full-face; 35, 40, pronotum, dorsal; 36, 41, left elytron, dorsal; 37, 42, protibia, upper side; 38, 43, metatibia, underside.

34

35

36

37

38

39

40

41

42 43


Antennal club pale-yellow. Propectus with ridge running from coxa to lateral margin. Mesosternum matt, scabrous, with fine setae. Metasternum poste-riorly with vague midline impression, anteromedian lobe with distinct pit; disc; abundantly punctate-setose, except on midline; metasternal wings and adjacent lateral parts with abundant, seta-bearing subocellate, matt punctures; general surface microre-ticulate. Abdominal sternites each with seta-bearing subocellate punctures along base, setae very long, up to 10 times punctural diameter; punctures medially effaced. Pygidium slightly convex, with abundant, locally seta-bearing, fine punctures, surface matt, due to microreticulation; base marginate, apex nar-rowly marginate.Protibia with 3 larger denticles, proximal serration extensive (12-13 small teeth, including reduced proximal denticle 4); terminal spur elongate-acumi-nate, curved; apico-internal angle rounded-obtuse, not penicillate. Protarsus long, slender. Meso- and metatibiae strongly dilated distad, mesotibia slightly sinuate, with subelliptic apical crest, fringed with spines; external fossorial elevations slightly devel-oped; spurs long, slender, acuminate. Femoral undersides all abundantly punctate-setose. Segment 1 of metatarsus shorter than segments 2-5 combined; approximate length proportions metatibial spur // metatarsal segments 1-5 36//36/17/11/8/17.Parameres simple, fig. 51.Measurements in mm. Maximum width of head 2.6. Median length of pronotum 2.6, maximum width 4.0. Sutural length of elytra 3.8, maximum width combined 4.7.

Variation and sexual dimorphism. Body length 6-8.5 mm. Major males have long postdiscal projection on their pronotum, minor males and females have a low, but well-pronounced angular projection at top of somewhat deplanate anterior declivity. Protibial dentation may also vary, a minor male having a more distinct proximal denticle (interpretable as having 4 denticles instead of 3). Parameres of minor male slightly different from holotype, mainly in propor-tions.

Diagnosis. O. vanasseni has its elytra completely setose, contrary to the two other species in its group; the seta-bearing punctures are relatively large, dis-cally more or less serially arranged, each bearing a microgranule. The proximal one of the external pro-tibial denticles is usually more or less sunk into an extensive proximal serration, resulting (at least in large specimens) in slender-looking 3-dentate protib-iae. Anterior lobe of metasternum with shallow pit.

Reddish-brown, forebody darker than rest. Clypeo- frontal ridge absent, interocular ridge distinct, its crest medially effaced or lowered in larger specimens (as in other species of the group). Pronotum with more or less deplanate anterior declivity, with long postdiscal, anteriorly curved horn in major males (apparently more erect than in sinagai), or with angu-lar protrusion on midline at about 0.4 from anterior border (minor males, females). Eyes very large, their border widely rounded in front. Ridge from procoxa running to prothoracic side distinct. Vertexal plate posteriorly delimited by arcuate ridge. Parameres relatively simple, curved (lateral view), tapering.

Derivation of species name. Dedicated to our ever helpful technical staff member in the Leiden museum, Fred van Assen.

Onthophagus variolaris group

Onthophagus vanderblomi Krikken & Huijbregts, sp.n.Figs 5, 34-38, 52

Material examined. Holotype male (RMNH), with label data as follows: Indonesia: SE Sulawesi: Kolaka District: Sanggona Base Camp, alt. 200 m, 13-17/10/1989, J. Krikken & K. van der Blom, #sw05b, multistratal evergreen forest, 2 fish traps. Paratypes. 11 male and female paratypes with same data, and 27 male and female paratypes as follows: 11 males and females: SE Sulawesi: Kendari District: Mekara, 7 km S of Lambuya, alt. 70 m, 30-04/10-11/1989, J. Krikken & K. van der Blom, #sw34a, Pinus-Acacia forest (plantation), 2 human excrement traps, 1 ex.; Kolaka District: Sanggone Base Camp, alt. 200 m, 9-12/10/1989, J. Krikken & K. van der Blom, #01a, second-growth forest, 2 human excre-ment traps, 1 ex.; same, but 13-17/10/1989, #sw03a, second-growth forest margin, 2 human excrement traps, 4 exx.; same, but #sw09b, second-growth-forest, combi-trap, bottom, 3 exx.; same, but #sw 05a, multistratal evergreen forest, 2 human excre-ment traps, 2 exx. 16 males and females: C Sulawesi: Banggai District: Matanyo Forest, N of Kayutanyo, alt. 170 m, 30-04/10-11/1989, J. Krikken & K. van der Blom, #sw18a, multistratal evergreen forest, 2 human excrement traps, 5 exx.; same, but alt. 120 m, 30-04/10-11/1989, #sw16a, multistratal ever-green forest, 2 human excrement traps, 2 exx.; same, but #sw16b, multistratal evergreen forest, 2 fish traps, 1 ex.; same, but, alt. 40 m, 30-04/10-11/1989, #sw15a, limestone forest remnant, 2 human excre-ment traps, 3 exx; same, but #15b, limestone


forest remnant, 2 fish traps, 1 ex.; same, but alt. 120 m, 30-04/10-11/1989, #sw17b, multistratal ever-green forest, 2 fish traps, 1 ex.; same, but alt. 120 m, 02-07/11/1989, #29b, multistratal evergreen forest, combi-trap, bottom, 1 ex.; Banggai District: Seseba Estate, alt. 80 m, 30-04/10-11/1989 #sw30b, multi-stratal evergreen forest, 4 fish traps, 1 ex.

Male (holotype). Body length ca 4.5 mm. Black-brown, elytra slightly lighter; head slightly matt, rest of dorsum shining between punctation; margins of head brown, legs brown. Pilosity abundant, pale-yellow, mostly very long, up to 0.5 mm. Clypeal border rounded, apex subtruncate, margin slightly reflexed; border at clypeogenal transition continuous; clypeofrontal ridge distinct, slightly arcuate, angularly connected with slight clypeogenal ridge; clypeal surface densely punctate, rugulate-punctate along margin. Frons with very low, slightly arcuate (anteriorly concave) transverse ridge between eyes, superficial ridges connecting ends of this ridge with ends of clypeofrontal ridge (thus forming trap-ezoid surface), surface with numerous punctures of different size (fine behind interocular ridge). Vertex unmodified; genal surface with numerous punctures, border widely rounded, not reaching occiput behind eyes. Eyes with 18-21 facet rows across widest point. Ratio interocular distance / maximum (transverse, single) eye width ca 2.5.Pronotum strongly, evenly convex, discal midline not impressed; anterior section of lateral border very slightly sinuate, anterolateral angle ca 85º, posterior section slightly sinuate, posterolateral angle rounded; anterior and lateral borders marginate; pronotal base widely rounded, virtually immarginate; pronotal sur-face densely, evenly, very distinctly punctate-setose, setae very long, erect; punctural densities on disc 20-25/0.25 sq.mm, diameters ca 0.05 mm. Elytra broad; striae discally well-defined, with shal-low punctures, mostly separated by 3-6 times their diameter, slightly crenulating interstriae; interstriae slightly convex, 1-7 with rows of fine, ill-defined seta-bearing punctures, one row on interstria 1, two on the others, 8 with scattered punctures.Antennal club pale-yellowish. Propectus laterally with ridge curving from coxa to anterolateral angle. Metasternum with anterior lobe convex, abruptly declivous in front; metasternal disc with numerous, sparse, simple seta-bearing punctures, metasternal wings and adjacent parts with sparse, seta-bearing subocellate punctures. Abdominal sternites each with transverse row of seta-bearing ocellate punc-tures. Pygidium abundantly punctate-setose; base marginate, apex narrowly marginate.

Protibia with 3 larger denticles, separated by serra-tion; proximal serration fine, extensive (ca 16 small teeth); apico-internal angle acute; terminal spur long, curved, tip acuminate (tips broken off ); pro-tarsus long, slender. Meso- and metatibiae slender, strongly dilated distad, mesotibia slightly sinuate; terminal spurs unmodified, spurs very long, acu-minate; apical crest of tibiae elliptic, with fringe of spines; elevations on external surface slightly devel-oped, with long setae. Profemoral underside strongly punctate-setose; meso- and metafemoral undersides abundantly punctate-setose. Meso- and metatarsi very long, slender; segment 1 of metatarsus slender, slightly curved, distinctly longer than segments 2-5 combined; approximate length proportions metatib-ial spur // metatarsal segments 1-5 20//31/9/5/4/8.Parameres, fig. 52.Measurements in mm. Maximum width of head 1.5. Median length of pronotum 1.8, maximum width 2.6. Sutural length of elytra 2.5, maximum width combined 3.0.

Variation and sexual dimorphism. Body length 4-6 mm. Colour variable, from black to brown, with or without metallic lustre, forebody may be darker than rest. Frontal elevation variably reduced, arcu-ate clypeofrontal ridge always distinct. Pilosity seem-ingly variable, but setae are just easily lost. Female has obtuse apico-internal angle on protibia, not the fine acute projection seen in males. Parameres seem slightly variable. Status of populations on differ-ent peninsulas to be checked when more material becomes available.

Diagnosis. O. vanderblomi is very closely related to sembeli described hereafter, but differs by its very large eyes, separated by ca 2.5 times their maximum eye width. Much of body strongly punctate-setose, most setae very long. Forebody usually black-brown and elytra dark-brown, largely shining. Head with low, arcuate, transverse clypeofrontal ridge, form-ing a vague frontal trapezium with frontal transverse ridge (but interocular elevations may be effaced). Protibia usually with 3 larger external denticles. Meso- and metatarsal segments 1 very long. Postocu-lar surface of propectus concave, delimited by ridge curving from coxal side to sharp anterolateral angle. Parameres relatively simple, curved (lateral view), tapering, tip dilated.

Derivation of species name. Dedicated to our able field companion, technical staff member of the Leiden museum, Kees van der Blom.


Onthophagus sembeli Krikken & Huijbregts, sp.n.Figs 6, 39-43, 53

Material examined. Holotype male (RMNH), with the following label data: Indonesia: N Sulawesi: Dumoga Bone NP: Toraut, alt. 234 m, 31-08/05-06/1985, J. Huijbregts, #HH356, multistratal evergreen forest, window trap. Paratypes. 9 male and female paratypes as follows. N Sulawesi: Dumoga Bone NP: Toraut, alt. 234 m, 10-21/08/1985, J. Huijbregts, #HH416, multistratal evergreen forest, window trap, 2 exx; same, but 27-31/05/1985, #HH344, 2 exx.; Toraut, alt. 217 m, 11-18/05/1985, J. Huijbregts, #HH321, multistratal evergreen forest, 4 human excrement traps, 1 ex.; same, but 18-22/05/1985, #HH329, 3 exx.; same, but 09-11/05/1985, #HH313. 1 female paratype from SE Sulawesi: Kolaka District: Sanggona Base Camp, alt. 200 m, 13-17/10/1989, J. Krikken & K. van der Blom, #sw03a, second-growth forest margin, 2 human excrement traps. – 1 female paratype from C Sulawesi: Banggai District: Seseba Estate, alt. 80 m, 06-09/11/1989, J. Krikken & K. van der Blom, #sw30a, multistratal evergreen forest, 4 human excrement traps.

Male (holotype). Body length ca 4.5 mm. Black-brown, elytra slightly lighter; head slightly matt, rest of dorsum shining between punctation; margins of head brown, legs brown. Pilosity abundant (limited

on head), pale-yellow, mostly very long, up to 0.5 mm. Clypeal border rounded, apex subtruncate, margin slightly reflexed; border at clypeogenal transition continuous; clypeofrontal ridge distinct, slightly arcuate, angularly connected with slight clypeogenal ridge; clypeal surface densely punctate, rugulate-punctate along margin. Frons slightly transversely raised between eyes, ends of this ridge with superficial ridges connected to clypeofrontal ridge (thus form-ing trapezoid surface), surface with numerous punc-tures of different size; genal surface with numerous punctures, border widely rounded, nearly reaching occipital side of head behind eye. Vertex unmodified. Eyes with 8-9 facet rows across widest point. Ratio interocular distance / maximum (transverse, single) eye width ca 8.0.Pronotum strongly, evenly convex, discal midline not impressed; anterior section of lateral border very slightly sinuate, anterolateral angle ca 85º, posterior section slightly sinuate, posterolateral angle rounded; anterior and lateral borders marginate; pronotal base widely rounded, virtually immarginate; pronotal sur-face densely, evenly, very distinctly punctate-setose, setae very long, erect; punctural densities on disc 20-25/0.25 sq.mm, diameters ca 0.05 mm. Elytra broad; striae discally well-defined, with shal-low punctures, mostly separated by 3-5 times their diameter, slightly crenulating interstriae; interstriae slightly convex, 1-7 with rows of fine, ill-defined

Figs 44-48. Onthophagus, body part contours. 44-48, watuwila, male holotype. 44, head, full-face, in profile; 45, pronotum, dorsal; 46, left elytron, dorsal; 47, protibia, upper side; 48, metatibia, underside.

44

45

46 47 48


seta-bearing punctures, one row on interstria 1, two on the others, 8 with scattered punctures.Antennal club pale-yellowish. Propectus laterally with ridge curving from coxa to anterolateral angle. Metasternal disc with slightly raised midline; ante-rior lobe abruptly declivous in front; metasternal disc with sparse seta-bearing simple punctation, metasternal wings and adjacent parts with sparse, seta-bearing subocellate punctures. Abdominal ster-nites each with transverse row of seta-bearing ocellate punctures. Pygidium abundantly punctate-setose; base marginate, apex narrowly marginate. Protibia with 3 larger denticles, separated by serra-tion; proximal serration fine, extensive (ca 15 small teeth); apico-internal angle acute; terminal spur long, curved, tip acuminate (tip may easily be bro-ken off ); protarsus long, slender. Meso- and metatib-iae slender, strongly dilated distad; mesotibia slightly sinuate; terminal spurs unmodified, spurs very long, acuminate; apical crest of tibiae elliptic, with fringe of spines; elevations on external surface slightly developed, with long setae. Profemoral underside strongly punctate-setose; meso- and metafemoral undersides abundantly punctate-setose. Meso- and metatarsi very long, slender; segment 1 of metatarsus slender, distinctly longer than segments 2-5 com-bined; approximate length proportions metatibial spur // metatarsal segments 1-5 (in male paratype) 21//32/8/4/4/9.Parameres, fig. 53.Measurements in mm. Maximum width of head 1.3. Median length of pronotum 1.8, maximum width 2.5. Sutural length of elytra 2.2, maximum width combined 2.9.

Variation and sexual dimorphism. Body length 4.5- 6 mm. Colour variable, from black to brown, with or without metallic lustre, forebody may be darker than rest. Frontal elevation variably reduced, arcu-ate clypeofrontal ridge always distinct. Pilosity seem-ingly variable, but setae are just easily lost. Female has obtuse apico-internal angle on protibia, not the fine acute projection seen in males. Status of popu-lations on different peninsulas to be checked when more material becomes available.

Diagnosis. O. sembeli looks like a narrow-eyed ver-sion of the previous species, O. vanderblomi. Eye shape and related head proportions aside, there are hardly any other differences; the interocular distance is ca 8 times the maximum width of a single eye. Much of body strongly punctate-setose, most setae very long. Forebody usually black-brown and elytra brown, largely shining. Head with arcuate clypeofrontal ridge, and low, arcuate, transverse frontal ridge, between them forming a vague frontal tra-pezium (but interocular elevations may be effaced). Protibia with 3 larger external denticles. Meso- and metatarsal segments 1 very long. Postocular surface of propectus concave, delimited by ridge curving from coxal side to sharp anterolateral angle. Para-meres relatively simple, curved, tapering (lateral view), tip dilated.One comment: southern populations known only from two females.

Derivation of species name. Named after the Indo-nesian entomologist Dantje Sembel, who, with his colleagues at Sam Ratulangi University, Manado, Sulawesi Utara, encouraged many Project Wallace

Figs 49-54. Onthophagus, contours of aedeagus, upper side (a) and lateral (b), arrow indicates approximate plane of view. 49, sinagai, holotype; 50, vanofwegeni; holotype; 51, vanasseni, holotype; 52. vanderblomi, holotype; 53, sembeli, holotype; 54. watuwila, holotype.

49a 50a 51a

52a 53a 54a

49b 50b 51b

52b 53b 54b


participants and was an important liaison with the local authorities.

Onthophagus watuwila group

Onthophagus watuwila Krikken & Huijbregts, sp.n.Figs 7, 44-48, 54

Material examined. Holotype male (RMNH), with the following label data: Indonesia: SE Sulawesi: Kolaka District: Watuwila Mosquito Camp, alt. 1150 m, 13-15/10/1989, J. Krikken & K. van der Blom, #sw10a, multistratal evergreen forest, 2 human excrement traps. Paratypes. 27 male and female paratypes with same data.

Male (holotype). Body length ca 5 mm. Forebody black (or very dark brown), elytra brown, all shin-ing, locally sericeous; margins of head, ventral parts, and legs brown. Pilosity pale-brown, abundant on ventral side, dorsal side glabrous. Clypeal border rounded; apex subtruncate, margin slightly reflexed; border at clypeogenal transition continuous; clypeofrontal ridge distinct, short, very slightly arcuate, not reaching vague clypeogenal suture; clypeal surface densely, transversely rugulate-punctate. Frons slightly transversely depressed half-way between eyes, with juxtaocular depression on either side; surface with crowded, somewhat rugulate punctation; surface behind depression abundantly finely punctate; frontovertex with pair of transverse, upright, tapering, blunt-tipped horns, not imme-diately adjacent to eyes; tip of horns slight curved backward (lateral view); gena subangulate, tip shortly rounded, surface densely punctate. Eyes large, with 13-14 facet rows across widest point. Ratio interocu-lar distance / maximum (transverse, single) eye width ca 3.2.Pronotum, apart from anterior declivity, slightly, evenly convex, discal midline not impressed; ante-rior section of lateral border very slightly rounded, anterolateral angle ca 90º, posterior section virtually straight, posterolateral angle rounded; pronotal base widely rounded, indistinctly marginate; pronotal surface densely, evenly, very distinctly subocellate-punctate; punctation laterally finer than on disc; punctural densities on disc 50-60/0.25 sq.mm, diameters ca 0.03 mm. Elytra broad, uniformly medium-brown; striae par-allel, fine, with small, shallow punctures, mostly separated by 3-5 times their diameter, slightly crenu-lating interstriae; interstriae slightly convex, with abundant, very fine, scattered, punctures on shiny,

somewhat sericeous, microreticulate background; striae 5&6 joined on apical declivity.Antennal club light-brown. Propectus with ridge running from coxa to lateral margin. Metasternal disc slightly convex, with shallowly impressed mid-line; anterior lobe unmodified in front; metasternal disc and anterior lobe with very fine, abundant, scattered, simple punctation, wings and adjacent parts with numerous seta-bearing subocellate punc-tures. Abdominal sternites each with transverse row of superficial, fine, seta-bearing ocellate punctures. Pygidium matt, distinctly microreticulate, sparsely, very finely, indistinctly punctate, glabrous; base mar-ginate, apex finely marginate. Protibia with 3+1 larger denticles, separated by serra-tion, plane of proximal denticle extended proximad; proximal serration fine, limited (4-5 small teeth); apico-internal angle rounded-obtuse, not penicillate; terminal spur long, curved, tip acuminate; protarsus long, slender. Meso- and metatibiae strongly dilated distad; terminal spurs unmodified, long, acuminate; apical crest of tibiae elliptic, with fringe of spines. Profemoral underside sparsely punctate-setose, anterior side between anterior and inferior ridges scabrous, matt; meso- and metafemoral undersides sparsely punctate(-setose). Segment 1 of metatarsus slender, about as long as segments 2-4 combined; approximate length proportions metatibial spur // metatarsal segments 1-5 24//25/12/7/6/10.Parameres complex, upper side encompassing pair of sclerotized projections; parameral tips broad, blunt; fig. 54.Measurements in mm. Maximum width of head 1.8. Median length of pronotum 1.6, maximum width 2.8. Sutural length of elytra 2.6, maximum width combined 3.1.

Variation and sexual dimorphism. Body length 4-6 mm. The type-series is generally rather constant, variation in colour and microsculpture taxonomi-cally insignificant; one small female light brown, probably immature. Females with clypeofrontal ridge longer than males, reaching clypeogenal suture; ridge in some males very short, hardly noticeable. Some smaller females (including immature mentioned) with obsolescent interocular horns.

Diagnosis. The ornamentation of the head of O. watuwila is unique among the large-eyed Sulawesi Onthophagus. Head usually with pair of upright, transverse horns, between posterior part of eyes, near the prothoracic margin; their taper-ing tip is slightly inclined backward. Clypeus with transverse, very slightly arcuate ridge, which in males is short (may be obsolescent), not reaching


clypeogenal sutures. Eyes large, interocular distance 3-3.5 times eye width. Dorsal side glabrous, punc-tation of pronotum dense, of elytral interstriae very fine and indistinct; interstrial surface moderately shining, sericeous. Forebody largely black, elytra and most other parts brown. Pronotum evenly, slightly convex (with steeper declivity behind the horns on the head). Pygidium matt, distinctly microreticu-late, base marginate. Protibia with 4 large external denticles and limited serration; apico-internal angle unmodified. Aedeagus complex, upper side with paired projections; parameral tips not simply taper-ing, not spatulate, but broad, blunt. No known rela-tives in the Oriental fauna; group could be endemic in Wallacean fauna. There are many narrow-eyed Sulawesi species with a pair of interocular horns, but none is directly related to O. watuwila (Krikken & Huijbregts in prep.).

Derivation of species name. Named after one of the mountains in the area.

AcknowledgementsOur ecological colleague I. Hanski (Helsinki, Fin-land) kindly left relevant Sulawesi material to us. In the field we were supported by enthusiastic local Indonesian staff; in the context of this paper the fol-lowing persons of Sulawesi are relevant: R. Lame-anda (Palu), I. Ladamay, T. Pakki, and I.M. Eben-eser (all Kendari), D. Sembel and M. Tulung (both Manado). S. Kahono (LIPI, Bogor/Cibinong) also gave valuable support.K.A. van der Blom (Leiden, The Netherlands) was our able field assistant during the 1989 trip. Our col-league J. van Tol (Leiden, The Netherlands) read a draft of this paper.

Thanks are also due to the team and sponsors of Project Wallace 1985 and our 1989 follow-up trip, including the Royal Entomological Society of Lon-don (United Kingdom), and in Indonesia: the Indo-nesian Institute of Science (LIPI, Jakarta), Sam Ratu-langi University (UNSRAT, Manado), and Haluoleo University (UNHALU, Kendari). The Uyttenboog-aart Eliasen Stichting supported the field work of J. Huijbregts during Project Wallace.

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und der angrenzenden Länder, mit Beschreibung von 14 neuen Arten und eine Unterart. – Folia Zoologica et Hydrobiologica 8: 303-353.

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Balthasar, V., 1969. Neue Onthophagus-Arten von Neu-Guinea und den benachbarten Inseln. – Acta Musaei Nationalis Pragae 38: 361-408.

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Received: 24 January 2008Accepted: 29 April 2008

sulawesi large-eyed onthophagus and their relatives: seven ... · 156 tijdschrift voor entomologie,...

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