Notes on North European Onthophagus Latr. (Coleoptera: ) uÅxeN LJUNGBERG

Ljungberg, H.: Notes on Norlh European Onthophagus Latr. (Coleoptera: Scarabaeidae). [De svenska horn- och dvärgdyvlarna, Onthophagus Latr. (Coleoptera: Scarabae- idae).1 - Entomologisk Tidskrift 123 (1-2):35-49. Lund, Sweden 2002. ISSN 0013-886x.

In order to clarify the number of Swedish species of Orzrå ophagus Latr. (Coleoptera, Scara- baeidae) and their distribution, a large parl of the material in public collections was studied. The number of species is nine: O. illyricus (Scopoli), O. ovatus (L.), O. joannae Goljan, O. nuchicornis (L.), O. vacca (L.), O. gibbulus (Pallas), O. fracticornis (Preyssler), O. similis (Scriba) and O. coenobild (Herbst). Of these, O. gibbulus is here reported for the first time from Sweden, based upon a small series of 19th century specimens previously misidenti- fied as O. vacca. Also O. taurus (Schreber) has been reporled from Sweden, but all speci- mens except one belong to the closely related O. illyricus and, since a mislabelling of the single O. taurus'specimen can not be excluded, the species is deleted from the Swedish list. The Swedish material of O. ovatus and O. joannae has not previously been revised using genital characters, and this paper presents a first attempt, giving a preliminary picture of their distribution. Of the two, O. joannae is the more widely distributed, while O. ovatus appears to have a predominantly eastern distribution, but there is considerable overlap and in some provinces both species occur. The examined Norwegian specimens of O. " ovatus" belong to O. joannae, which is probably the only one of these two species occurring in Norway. A single specimen of the southern species O. grossepunctatus Reitter is conside- red to be mislabeled. The separating characters between O. fracticornis and O. similis have previously been incorrectly described, resulting in a large number of misidentifications. Here, reliable separating characters are given for both sexes of the two species. When the misidentifications are corrected, O. similis emerges as a more southern species than hither- to assumed. A revised key including all species known from the area and illustrating the mosl important characlers is given.

H. Ljungberg, Dept. of Quaternary Geology, Lund University, Tornavägen 13, SE-223 63

Lund, Sw e den. E -mai L : hakan.li un g b e r g @ ge o L lu. s e.

Introduction Together with the related genera Copris O.F. long, warm summers to complete their develop- Miiller and Caccobir.rs Thomson, the genus ment, and as a consequence the group is poorly Onthophagus Latr. contains the most northerly represented in norlhern latitudes. In a nature con- representatives of the subfamily , a servation context, the Scarabaeinae stand in a group of coprophagous lamellicorn to class all by themselves it is one of the groups which also the famous holy Scarab of Egypt be- where all Swedish species- are red-listed (Gär- longs. Ecologically these genera belong to the denfors 2000). The fact that all our species are so-called paracoprids (Gustavsson 1998), which thermophilous and in Sweden reach their provide for their young by burying dung in tun- northern distribution limits makes them especial- nels under the dung heap. Paracoprids require ly vulnerable to climate change on one hand and

35 Håkan Ljungberg Ent. Tidskr. 123 (2002) changes in farming practices on the other. Loss and fragmentation of pastures on dry, sandy soils as well as a deteriorating microclimate re- sulting from a general decrease in grazing pres- sure are factors that have affected our species negatively. Landin (1951) lists six Onthophagus-species from Sweden'. O. taurus (Schreber), O. ovatus (L.), O. nuchicornis (.L.), O. vacca (L.), O. frac- ticornis (Preyssler) and O. coenobita (Herbst). Since then, no less than three of our species have been subdivided into pairs of sibling species: O. fracticornis into O. fracticornis s. str. and O. si- milis (Scrlba) (Landin 1959), O. oyatus into O. ovatus s. str. and O. joannae Goljan (Lundberg 1980), and O. taurus into O. taurus s.str. and O. illyricus (Scopoli) (Lundberg 1980). With these additions, the number of species listed from Sweden increased to nine (Lundberg 1995). However, the characters identifying the new species were never published in Swedish, many Fig. l. Male of Onthophagus gibbulus Sweden. specimens were not correctly identified, and the from Actual size of specimen: I I mm. distribution of our species remained unclear. As the interest in faunistic and ecological studies of Ett av de skånska exemplaren av Onthophagus dung beetles has recently increased (e.g., Pitkä- gibbulus. nen & Roslin 2001), it has become apparent that the Swedish material of Onthophagas is in need are also behaviorally distinct: while the large of revision. The aim of this paper is primarily to males typically assist females in larval provisio- clarify the number of species occurring in Swe- ning, the small males do not. An allometric de- den and their distribution, thereby laying a firm velopment of the sexondary sexual characteris- foundation for further studies; secondly to faci- tics is evident also in several other Onthophagus litate their correct identification in the future. As species, and as shown here it is not restricted to mentioned above, substantial taxonomical chan- the sexual ornamentation of the males. Failure ges have taken place since the publication ofthe to recognize this has lead to enors in the inter- latest fauna (Landin 1957), and an extended and pretation of at least one species pair O. fracti- revised key is here presented. cornis/O. similis (see below). Since secondary In spite of the characteristic rnorphology and sexual characters are of great importance, keep- striking sexual ornamentation of Onthophagus ing the sexes separate facilitates identification. many species are quite difficult to separate, due In small specimens, the secondary sexual char- to the large intraspecific variation. Since much acters are often weakly developed, and the sexes of the external morphology is related to and are externally similar. The most reliable way of affected by variation in body size, small speci- sexing such specimens is by studying the abdo- mens of either sex are often difficult to identify. minal sternites (fig. 2A, 2B). In O. ovatus and O. Hunt e/ al. (1999) has shown that the develop- joannae, the sexual dimorphism is less pronoun- ment of the horns in male ced, and the male does not have the posterior is not linearly related to body size. Ratheq a head ridge developed into a horn. The male of population of O. taurus contains two distinct these species is characterized by having only the male morphs: large males with large horns and posterior head ridge well developed, while in small males with small horns. The two morphs the female both head ridges are equally strong.

36 Ent. Tidskr. 123 (2002) Notes on North Eurctpean Onthophagus

5. Pronotum with weak bronze lustre or virtually unmetallic black. Elytrai epipleura dark ante- A riorly. On average smaller, 6-9 mm...... O. nuchicornis Pronotum clearly metallic greenish or coppery. Elytral epipleura entirely yellowish brown, only rarely darkened anteriorly. On average larger, 7-13 mm (rarely below 10 mm) ...... O. vacca 6. On average larger, 8-15 mm (rarely below l0 mm). Pronotum unmetallic black, only rarely B with a weak bronze lustre. Front angles ofprono- tum with rather line and sparse punctuation. pro- notum in the female with a distinct tubercle at middle of anterior margin...... O. gibbulus On average smaller, 4.5-10 mm. Pronotum with metallic lustre: greenish or copper. Punctuation

Fig. 2. Abdominal sternites of Onthophagus sp. in ::il,:'":: ::::: :i:::::::: ::-:: :::::::T ventral view. A: male, B: .female. Redrawn .from 7. Pronotum vividly metallic green or copper. Elytra Macharschke ( 1969). almost entirely yellowish brown, dark markings diffuse, few and scattered, never confluent. Pro- Bakkropp av Onthophagus sp. notum in the female with a distinct tubercle at anterior margin ...... O. co enobita Pronotum with a weaker metallic lustre, dark Key to the North European species of greenish or coppery. Dark markings of elytra nu- Onthophagus Latr. merous, more or less confluent. Anterior margin 1. Sides of pronotum anteriorly convex or straight of pronotum in the female without tubercle ..... 8 (fig. 3)...... 2 Posterior head ridge in the f'emale broadly exten- Sides of pronotum anteriorly more or less sinuate ded, slightly curved in dorsal view (fig. 8A), seen (.e.g., fig. 124). Sometimes the sides are almost from behind gradually rising towards the middle straight, but in such cases the lateral bead is deve- (fig. 9A). Horn in well-developed males with loped into a small blunt tooth (fig. 8A) ...... 6 broad base (fig. 104), in side view bent sharply 2. Elytra uniformly black or (entireiy or partly) dark upwards (fig. 11A). Cheek in front of the eyes reddish/brownish ...... 3 more or less strongly dilated, angular (fig. 84, - Elytra distinctly bicoloured,with inegular dark 104), less so in small specimens (fig. 124). On markings contrasting strongly against a pale average larger, 5.5-9.5 mm. Male genitalia fig. yellowish-yellowish brown background ...... 5 134, C: parameres in ventral view with rounded 3. Large (8-1 1.5 mm in Swedish specimens), punc- tip, in lateral view with a backwards directed pro- tuation on disc of pronotum simple also in the jection ...... O. fractitornis anterior part ...... r...... O. illyricus Posterior head ridge in the female shorter, per- - Small (4-5.5 mm), punctuation on disc of prono- fectly straight in dorsal view (fig. 8B), seen from tum coarse and granulate in the anterior part ... 4 behind laterally sharply rising in the lateral part 4. Elytra dull, with strong microreticulation that and then maintaining approximately the same (although sometimes indistinctly) extends api- height throughout (fig. 9B). Horn in well-deve- cally all the way to the suture (fig. 4A). Posterior loped males with narrow base (fig. 10B), in side head ridge in large males straight (fig. 5A). Male view bent only slightly upwards (fig. 11B). Cheek genitalia fig. 6A, C, E, female genitalia fig. 7A. in front of the eyes less strongly dilated, rounded O. ovalus (fig. 10B, 12B), only in large specimens forming Elytra more shiny, with sligthly weaker microreti- an obtuse angle (fig. 8B). On average smaller, culation, lst interval apically slightly elevated 4,5-7.5 mm. Male genitalia fig. l3B, D: parame- and here entirely (or almost so) without microreti- res in ventral view with flared tip, in lateral view culation (fig. aB). Posterior head ridge in large without projection ...... O. similis rnales usually curved (fig. 58). Male genitalia fig. 68, D, F, female genitalia flg. 78 ..... O. joannae

1t Håkan Liungberg Ent. Tidskr. 123 (2002)

status of all coprophagous Scarabaeidae is under

preparation (M. Forshage , pers. comm.). For this reason, notes on distribution are given mainly to the level of province, and discussed in greater detail only when they differ fiom those publis- hed in the latest edition of Catalogus Coleop- terorum Sueciae (Lundberg 1995). The public collections investigated are the following: Zoo- logical Museum, Lund (ZML), Natural History Museum, Gothenburg (GNM), National Muse- um of Natural History, Stockholm (NRM). The nomenclature follows Lundberg ( 1995).

O. taurus and O. illyricus Fig. 3. Head and anterior part of pronotum of The species O. ttturu,s (s.1.) was first reported (OlLtnd. Sandby). The side from Sweden by Gyllenhal (.1821). As reported of the pronotum is convex all the way to the Jrr.tnt (.1982), almost all of the Swedish angle (arrow). by Lundberg material was later assigned to O. illyricus, the Framkrtpp uv O. nuchicornis. exception being two specimens from Gotland and one from Skåne. O. taurus and O. illyricus Notes on the species are extremely similar, and their specific status In the following paragraphs, the differences bet- has often been questioned. The morphological ween the species are discussed and additional characters mentioned in the literature are rather diagnostic characters are given. The descrip- vague. In O. taurus, the punctuation of elytra is tions are not intended to be exhaustive. but me- weak and simple, leaving at least 2th-4th elytral rely to supplement those already given in the li- interval glabrous. The punctuation on the steep, terature (only the commonly confused species anterior part of pronotum is considerably O. fracticomls and O. similis are treated in weaker than on the central part. ln O. iLlyricus, somewhat greater detail). New data concerning the punctuation of elytra is strong, at least the Swedish distribution is presented. An in- towards apex granulate, and the pubescence ex- depth treatment of the Swedish distribution and tends over the entire surface (if not abraded).

Fig. 1. Apical part of elytra in typical specimens o.f A: Onthophagus ovatus (Gotland, Rone) andB: O.joannae (Gotland, ValL), showing the microreticulation of the I st interval (arrow).

Täckvingarnas spetsparti hos typiska individer av O. ovatus och O. joannae.

38 Ent. Tidskr. 123 (2002) Notes on North European Onthophagus

Fig. 5. Head oJ weLl-developed males of A: Onthophagus ovatus (Blekinge, Ronneby) and B: O. ioannae (Skåne, Kullaberg), in dorsalview, showing the posterior head ridge (arrow).

Huvud av yäLutvecklade hanar av Onthophagus ovatus och O. joannae, visande den bakre pannlistens Jorm.

ovatus E

joannae ,D njoannae F ffiN Fig.6. Male genitalia of Onthophagus ovatus (A, C, E) and O. joannae (8, D, F). Left column: apical part of aedeagus, above lateral view, below: dorsal view. \'\l/ This column: lamella copulatrix and G: endophallus of O. ovatus, showing the position of the lamella ffijoannae copulatrix. After Krell & Fery (1992).

Hanliga genitalier av O. ovatus och O. joannae.

39 Håkan Ljungberg Ent. Tidskr. 123 (2002) (numerous specimens in ZML, GNM, NRM). B The last of the alleged O. taurus-specimens is a .'.- \ worn and unmetallic, rather small male (former- in t'..'\/ .,\ ly coll. Wir6n, now in ZML). Unforlunately, l-, i \ the genitalia of this specimen were lost during \-)\_t preparation, but the external morphology of the specimen conforms with that of a typical O. tau- 'Fm ras. This specimen caries only the label "Gtl.", without yeaq locality or even collector. The la- bel is hand-written but does not seem to be the joannae original. Since collectors in the I 9th century fre- quently traded specimens and collections com- Fig. 7. Female genitalia of A: Onthophagus ovatus and B: O.joannae. AJter KrelL & Fery (1992). monly contained a mixture of Swedish and exo- tic specimens (often without locality label), the Honliga genitalier av O. ovatus och O. joannae. provenience of this specimen is not beyond doubt. There are specimens of O. taurus also in The punctuation on the steep, anterior part of Zetterstedt's collection (ZML),but none of them pronotum is only slightly weaker than on the canies a locality label. Thus, while I have not central part. Recently differences have been been able to check every single Swedish record, found in the male genitalia, indicating that the all well-documented Swedish specimens previ- two forms are indeed separate species (Krell & ously claimed to be O. taurus obviotrsly belong Fery 1992). However, the Swedish specimens to O. ilLyricus. were identified before the genital dift'erences In summary, the existence of O. taurus in were known, and the conclusion that our materi- Sweden rests upon a single, questionable speci- al consists of both species was formed upon ex- men. In light of the more southern distribution ternal morphology alone. Personally, I always ofthis species (Krell & Fery 1992) andthe pos- doubted that both species were present in the sibility of mislabelling, in my opinion O. taurus Swedish material, because it seemed impro- cannot be accepted as a member of the Swedish bable that these two sibling species would end fauna. Consequently, the species is not included up coexisting in the same small, geographically in the key, but I have illustrated the male genita- isolated area (on the Baltic island Gotland), and lia for comparison (fig. 14A, 14B). In Norlhern nowhere else in northern Europe. Such a scena- Europe O. illyricus is known from the southwes- rio seemed far-fetched, regardless of whether tern part of Gotland (several records) and Söder- the isolated occurrences were the result of recent manland (one specimen in NRM, caught in a colonisations or (the most probable version) the Iight trap and almost certainly accidental). The last remnants of shrinking, formerly larger dist- latest record from Gotland dates from 1956 ributions. For this reason, I felt that the Swedish (ZML). Finally, the record of O. illyricus from material needed to be reinvestigated. Skåne 1972 (Lundberg 1980) is based on an in- When O. taurus (s.1.) was first reported from correctly identified specimen of very strange Sweden (Gyllenhal 1827'),the description of the appearance (in the taxonomical collection of colour as "aeneo-micans" clearly indicated O. ZML). This specimen is a large male, carrying illyricus rather than the usually unmetallic O. the single horn typical of the subgents Palae- taurus. Other 19th century-specimens seen by onthophagus Zunino (Krell & Fery 1992) in- me, collected by Belfrage and Fal16n (ZldL), stead of the paired horn of O. taurus/O. illyricus belong to O. illyricus. The specimen from San- (subgenus Onthophagws s.str.), so the misidenti- da, collected by Anton Jansson in 1926 (see fication is obvious. In other respects, the speci- Lundberg 1982), is also an O. illyricus (M. Fors- men agrees most with O. illyricus, with simple hage, pers. comm.), as are all other 20th century- (not granulate) punctuation of pronotum and en- specimens that I have been able to examine tirely dark elytra. As fär as I know, no European

40 Ent. Tidskr. 123 (2002) Notes on North European Onthophagus

Fig. B. Head of well-developed .females oJ Onthophagus fracticornis (Gotland, Hangvar), left, and O. similis (Skåne, Kullaberg), right, in dorsal view. Single arrow: cheek angle, double arrow: width oJ posterior head ridge. Not to scale.

Huvud av vtilunecklade honor av Onthophagus fracticornis och O. similis.

species of Onthophagrr matches this descrip- weakly developed and always straight (fig. 5A), tion. It appears that the forebody has been glued while it in O. joannae is more elevated in both on to the rear part of the body, so it is even pos- sexes and sometimes crescent-shaped in the sible that the specimen is in fact a composite of male (fig. 5B). The degree of development of two different species. ln any case the specimen the head ridges is highly variable, and not of is probably not of Swedish origin, and certainly much use for separating the species. As to the not of faunistic interest. crescent-shape ofthe posterior head ridge in the male I have not seen any specimens of O. ovatus O. joannae and O. ovatus displaying this curvature, but on the other hand To separate these species on external characters it is only developed in the largest males of O. alone is very difficult. I have very little to add to .joannae and is therefore of restricted value. In the characters given in the key, except that there many O. joannae-males the ridge is perfectly is some variation. and that some specimens may straight. The swelling present in large speci- not be possible to identify with absolute certain- mens at the middle of the anterior margin of the ty on external morphology. According to Baraud pronotum is allegedly simple in O. ovatus,bi- (1992) the posterior head ridge in O. ovatus is partite in O. joannae (Hansen et al. 1993),but

B

Fig. 9 (leJi). Head oJ well-developedJemales of A: Onthophagus fracticornis (Gotland, Rone) and B: O. similis (Skåne, Genarp), ,seen from behind, showing the shape oJ the posterior head ridge (stippLed). Original.

Huvud av välutvecklade honor tw Onthophagus fracticornis och O. similis, visande den bakre pannlistens .form.

41 Håkan Ljungberg Ent. Tidskr. 12-r (2002)

Fig. 10. Head of well-developed males of A: (Skåne, Flyinge), in dorsal view. SingLe arrow: cheek angle, double amtw: width oJ bttstil part of horn. S: suture between clypeus and cheek. Not to scale.

Huvud av väluilecklade hanar av Onthophagus.fracticornis och O. similis.

this difference is small and can only be observed in the apical part of the lst elytral interval (fig. in the largest, most well-developed specimens. 41., 4B), although there is some variation also O. joannae often has a somewhat more pro- here. Luckily, the diff'erences in male and nounced bronze lustre than O. ovatus, but also f'emale genitalia are constant (fig. 6-7). When this difference is not significant. The most reli- the male genitalia have been extruded, the inner able external character is the microreticulation armature can be extracted through the basal

Fig. ll. Head of well-developed males of A: Onthophagus fracticornis (Otand, Resmo) and B: O. similis (Skåne, Flyinge), seen from left side, showing, the shape ofthe horn (stippled). Original.

Hom hos vcilunecklttde hanar av Onthophagus fracticornis och O. similis.

42 Ent. Tidskr. 123 (2002) Notes on North European Onthoph.agus

Fig. 12. Head of small male.s of A: Onthophagus fracticornis (Oland, Re1mo) and B: O. similis (Skåne, Siivåkra), in dorial view. Arrow:'cheek angle. Noie the similar devektpment of the posterior head ridge, and the absence oJ a horn. Not to scale.

Huvud av små hanar tw Onthophagus fracticornis och O. similis

opening, and the sclerites (namely Ihe Lamella Blekinge, Öland and Gotland. Only the record copulatrix) studied. from Småland remains unclear, and in the light Landin (1957) gives the distribution of the of the distribution of the two species it could collective taxon O. ovatus as Skåne, Blekinge, belong to either one (or both). In central Europe, Halland, Småland. Öland. Gotland. Östergöt- O. joannae and O. ovatus often coexist, but I land and Västergötland. In a preliminary reporl know of no recent Swedish locality where both (Lundberg 1980), O. joannae was listed from species can be found together. In a survey of the Skåne, Blekinge. and Halland, while O. ovatus dung fauna of open, grazed pine forests was listed from Oland and Gotland; but many of on Gotland, O. joannae was recorded from three the Swedish records were not checked. I still localities, O. ovatus from two. In no locality did have not had the opportunity to work up al1 Swe- both species occur (Croneborg 2001). dish material, but I have seen the greater part of it including voucher specimens for almost all O. grossepunctatus provincial records (only from Småland could no Of this South European species there is a single specimens be located). All specimens from wes- specimen in GNM (until now erroneously iden- tern Sweden (Skåne, Halland, Västergötland) tified as O. joannae), which according to the la- seen by me belong to O. joanilae (ZML, GNM), bel was collected in 1958 near Kinna in Väster- while all specimens from Öland belong to O. götland (A. Törnvall leg.). O. gro,tsepunctatus is ovatus (ZML, GNM). From Blekinge there is a Mediterranean species, which barely reaches only a small series of specimens collected near Central Europe in Slovakia and southeastern Ronneby in the 1880's (ZML), which actually Poland (Bunalski 1999). The occurrence of this consists of both species. Also from Gotland, species in Sweden is therefore highly unlikely, both species are known (ZML). To summarize, and there is no doubt that the specimen is either O. joannae is kno.wn from Skåne, Blekinge, introduced or (more probably) simply mislabe- Halland, Gotland, Ostergötland and Västergöt- led. For this reason, the species is not included land. Two 19th century-specimens from Norway in the key. O. grossepunctatus is easily separa- (Kongsberg) inZ}dL also belong to this species. ted from O. joannae and O. ovatus on the punc- The distribution of O. ovatus on the other hand tuation and microsculpture of the elytra (Krell & seems to be restricted to the eastern provinces Fery 1992).

43 Håkan Ljungberg Ent. Tidskr. 123 (2002)

similis ) Fig. 1 3. Apical part of aedeagus in males of Onthophagus fracticornis (A and C) and O. similis (B and D). A and B = ventraL view, C and D = lateral view. Redrawn and modified.from Landin (1959).

Hanliga genitalier av O. fracticornis och O, similis.

O. nuchicornis O. vacca The most common identification problem in the The larger size in combination with the dark Swedish fauna is that of distinguishing O. green lustre ofthe forebody should suffice to se- nuchicornis from O. fracticornis and O. similis parate this species from the preceding. In Swe- (on how to separate the latter two, see below). den O. vctccais known only from the southern- Although the differences in the shape of the pro- most province Skåne. There are no 20th century notum seem straightforward enough there is records of this species from Sweden; but it still some variation. The most obvious difference, occurs in Denmark, and there are records also valuable already in the field, is colour: O. nuchi- after 1950 in the northwestern pafi of Zealand cornishas pale yellow elytra with the black mar- (Hansen 1996). kings sharply delimited, while O. fracticornis and O. similis have more reddish-brownish O. gibbulus elytra with less contrasting dark markings. The The distinctly sinuate sides of the pronotum (fig. forebody is usually less metallic tn O. nuchicor- l) immediately sets O. gibbulus aside from O. nls (often almost unmetallic), but the difference vctcca. From O. fracticornis, O. similis and O. is not constant. The female of O. nuchicornis is coenobita typical specimens of O. gibbulus are easily recognized on the strong tubercle at the distinguished by the larger size and the unmetal- middle of the anterior edge of the pronotum, a lic black forebody. Strangely enough, the exis- character shared only with the rare species O. tence of this large and spectacular species in vacca, O. gibbulus and O. coenobita. Sweden has been overlooked until now. How- In Sweden, O. nuchicornls is recorded from eveq there are three specimens of O. gibbulus most provinces nofth to Uppland and Värmland collected in June 1860 at Kiviks Esperöd in (Lundberg 1995), and it is today probably the eastern Skåne in company with several speci- most widespread and least uncommon of our mens of O. vacca (L.) and placed under that species. Nevertheless it has decreased strongly, name in the geographical and taxonomical and north ofthe southern coastal provinces only collections of ZML. Also in C.G. Thomson's a few recent localities are known. It is more collection (ZML) a specimen of O. gibbulus is strongly restricted to sandy soils than O..fracti- present under the name O. vacca, tnfortunately cornis, and is therefore locally less common without locality label. It is a bit surprising that than that species, e.g. on the alvar of the Baltic Thomson overlooked this specimen, since islands Öland and Gotland. correctly identified specimens of O. gibbulus

44 Ent. Tidskr. 123 (2002) Notes on North European Onthophagus

conclusion was apparently based largely upon misidentified specimens. These measurements have been quoted repeatedly (e.g., Machatschke 1969, Baraud 1992), giving the impression that this is a well-established fact. In reality, the smallest O. fracticomls measure no more than 5.5 mm, while the largest O. similis reach almost 7.5 mm (according to Krell & Fery (1992) even 8 mm). The size overlap is thus considerable. Also several other published characters are of doubtful value or even misleading. To begin with, the alleged difference in the maxillary palps (Landin 1959) is imaginary. The difTeren- ce in the slope ofthe anterior edge ofthe prono- tum towards its front angles (Machatschke 1969) is insignificant and misleading. Such a Fig. 14. Apical part of aedeagus of A: Onthophagus difference i.llyricus and B: O. taurus in lateral view. At'ier Krell only exists in large and well-develo- & Fery (1992). ped males, and is a consequence of the anterior depression of the pronotum being broader in O. Hanliga genitalier av O. illyricus och O. tauras. fracticornis, to accommodate for the broader horn (see fig. 10A, 108). In small males, there is (under the name O. austriacus Panz.) from other no difference between the species. A more seri- pafts of Europe are present in his collection. ous mistake is the claim that females of O. simi- Actually, the species is quite easy to identify /is differ from females of O..fracticornis by ha- (see key). ving a weaker development of the head ridges Like O. vacca, O. gibbulus is a thermophi- (Landin 1959, Machatschke 1969, Baraud lous species, restricted to dry, open pastures on 1992). Not only is this assumption emoneous. deep sandy soils (Bunalski 1999). The European but it will lead to almost certain misidentifica- distribution is eastern, and the closest occurren- tions if applied. The reason for this is that the ces are in northeastern Poland, the Baltic states secondary sexual characters in these species (the and southern Finland; where it was rediscovered head ridges of the females as well as the homs of as recently as in 1995 (Pitkänen & Roslin 2001). the males) are allometrically developed, i.e. There are no recent Swedish records of O. gib- more well-developed in large specimens. Speci- bulus, and the species is probably yet another mens in the size interval where O. fracticornis member of the growing assemblage of copro- and O. similis overlap are either small speci- phagous beetles that have gone extinct in Swe- mens of O. fracticornls (having weakly develo- den during the last 100 years. , ped secondary sexual characteristics), or large specimens of O. similis (having strongly develo- O. fracticornis and O. similis ped secondary sexual characters). Thus, within These species are very often misidentified in this size interval females of O. similis will tend collections, partly because the differences be- to have more strongly developed head ridges tween them have not been correctly described. than females of O. fracticornis, in other words Landin (1959), lists several diagnostic charact- the exact opposite of what has been commonly ers, but then unforlunately turns to body size as a assumed. As a matter of fact, when equally well- reliable way of identifying the species. Landin developed females are compared, the head rid- gives the size of O. fracticornls as 7-9.5 mm, ges tend to be more strongly elevated in O. simi- that of O. similis as 4-7 mm, and concludes that /is (fig. 8). The claim that the punctuation be- there is no size overlap (although his wording tween the head ridges of the female is coarser in suggest some unceftainty about this). This O. fracticornls (Machatschke 1969, Baraud

45 Håkan Ljungberg Ent. Tidskr. 123 (2002)

1992) is likewise incorrect, also for reasons of of the head ridge in the female can usually be allometry. According to Baraud (1992) the sutu- discerned also in rather small, poorly developed re between clypeus and cheek (indicated in fig. specimens, where the ridge is merely suggested. l0A) is evident in O. similis but obscured by Excluding secondary sexual characters, the coarse punctuation in O. fracticomls; but this is most reliable external character is the cheek not the case. The punctuation is generally coar- angle, which is described by Landin (1959), but ser in females than in males, and coarser in large not quoted by subsequent authors. This charac- specimens of both species (compare fig. 8A with ter is less constant than assumed by Landin, be- l2A and fig. 88 with 12B), but there is no cons- ing subject to the same allometric variation that tant difference between the species (compare affects the development of the head ridges (but fig. 8A with 88 and fig. 12A with 12B). Conse- to a lesser degree). As a result, the smallest spe- quently, the suture between clypeus and cheek is cimens of O. fracticomis approach the largest usually visible in small specimens (e.g. fig. l2A, specimens of O. similis. This is clearly seen 12B) but not in large specimens, especially when comparing fig. 12A (small O. fracticornis) females (fig. 84, 8B). with fig. 10B (large O. similis). However, the These emors. combined with the mistaken variation is not so large as to render the character assumption that there is no size overlap between useless. In intermediate specimens, the allome- the species, has lead to the situation that (at least tric development of the secondary sexual char- in Swedish collections) large specimens of O. sl- acteristics can actually be helpful in the identifi- milis have regularly been identified as O. fracti- cation, if correctly interpreted. Since specimens cornis, and small specimens of O. Jracticornis in the size interval 6-7 mm are either rather as O. similis.In the collections of ZML. almost small O. fracticornis or rather Targe O. similis, one third of the specimens were misidentified. already the degree of development of the head The fact that misleading diagnostic characters ridges or of the horn will give a clue as to which are given in several keys (e.9., Balthasar 1963, species is involved. In other words, although Machatschke 1969, Baraud 1992), makes me very small specimens of O. fracticornis wrll suspect that also part of the Central European have cheek angles similar to those of large O. material may be misidentified. similis, such specimens will usually be characte- Fortunately, there are a few good separating rized by a very weakly developed sexual orna- characters. While the strength of the head ridges mentation (again, compare fig. l2A with fig. is subject to individual variation and can not be l0B). In addition to the characters mentioned in used to separate the species (see above), the sha- the key, there are differences also in the shape of pe of the posterior head ridge in the female dif- the pronotum, O. similis having a broader pro- fers constantly between the species (fig. 8-9), a notum with more rounded sides, whereas the fact that has not previously been observed. As pronotum in O fracticornis is narrower and correctly pointed out already by Hansen (1958) more bottle-shaped (except in the largest males). and Landin (1959) the posterior head ridge is Also the colour of the pronotum is often (but not more broadly extended in O. fracticornis, b:uI always) different, O. similis tending towards more importantly it is in O. similis more well- green, while O. fracticornls typically has a defined, rising sharply in the lateral part. Also bronze lustre. the horn of the male is differently shaped in the Combining the abovementioned characters, two species (fig. l0-11). According to O. fracticornis and O. similis are far from hope- Machatschke (1969) the horn in O. fracticornis less to distinguish, and can often be identified forms a 90' angle with the surface of the head already in the field under a hand lens. To sum- (1.c., p.291), but this is only the case in extreme- marize, females of all sizes are best separated on ly large males; in most cases the angle is clearly the shape of the posterior head ridge, supple- obtuse (frg. 11A). Due to the abovementioned mented by the shape of the cheek. Large males allometry these characters are of most use on are easily distinguished on the shape ofthe horn, large, well-developed specimens, but the shape while in small males the cheek is the most

46 Ent. Tidskr. 123 (2002) Notes on North European Onthophagus reliable external character. Please note that For the future small males of both species (fig. 12A, l28) will As seen here the list of Swedish Onthophagus have a posterior head ridge shaped like that of contains nine species: O. illyricus (Scopoli), O. small females of O. fracticornis, so the sexes ovatus (L.), O. joannae Goljan, O. nuchicornis should be identified on the shape of the abdomi- (L.), O. v ac c a (L ;), O. gibbulus (Pallas), O. fr ac - nal sternites (fig. 2A, 2B). Naturally, genital pre- ticornis (Preyssler), O. similis (Scriba) and O. parations of all available males should be made coenctbita (Herbst). The notes on distribution gi- to secure the identification. ven here should be viewed as preliminary, for Landin (1959) lists O. similis from Skåne, the simple reason that I have not been able to Blekinge. Halland. Ötand. Gotland. Östergöt- study all Swedish material, and there remains a land, Västergötland and Bohuslän. From Oster- possibility that additional provincial records götland and Västergötland I have not been able may turn up. However, in view of the scarcity of to locate any correctly identified O. similis,btttl material of these species from all but the south- have seen misidentilied specimens of O. .fracti- ernmost provinces, I consider the chances of cornis, upon which these.provincial records pro- substantial additions slight. Our Onthophagus- bably were based (Ostergötland, Omberg species are actually in a precarious state, and merely summing up the provincial records does Göteborg (GNM)). In the absence of other veri- not give any idea about their current distribu- fication I find it justified to delete O. similis tions. No less than three and possibly four of our fiom Östergötland and Västergötland. With the- species are regionally extinct, and the remaining se corrections, O. similis appears to be a deci- have also declined strongly, especially in the dedly southern species, known only from the norlhern parts of their distributions. This is, coastal provinces Skåne, Blekinge, Halland, however, the subject of another study. With this Öland, Gotland and Bohuslän. As a matter of paper I only hope to have shed some light on our fact also the records of O. similis from Finland Onthophagus-species, and how they should be (Biström et al. 799I) seem to be erroneous, identified. These fascinating deserve being based upon misidentified O. fracticornis more attention! (Forshage pers. comm.). O. fracticomls on the other hand has been recorded from most provin- ces north to Dalarna (Lundberg 1995), but has Acknowledgements decreased strongly in the northern provinces and Mattias Forshage, Åkersberga, has kindly given me is today almost entirely restricted to the southern access to a large database of faunistic records of Swe- coastal provinces. In Skåne, O. similis is locally dish dung beetles. The curators Roy Danielsson the most common Onthophagus-species, but (ZML),Ted von Proschwitz (GNM) and BeftViklund further north it is rare and almost entirely restric- (NRM) have generously lent me material from the ted to pastures on sandy soils. collections of respective museum. Per Douwes kindly allowed me to use equipment for digital microphoto- O. coenobita graphy. Ragnar Hall and Mikael Sörensson has com- A vividly metallic forebody in combination with mented upon the manuscript and suggested valuable almost entirely yellowish elytra renders this spe- improvements. cies unmistakeable. Like O. vacca and O. gibbu- lus it is restricted to the southernmost province References Skåne. The latest Swedish record is from Fal- Balthasar, V. 1963. Monographie der Scarabaeidae sterbo in southwestern Skåne in 1939 (ZML). und Aphodiidae der palearktischen und orientali- schen region. Band 2, Coprinae. Verlag der but O. coenobita stlll occurs in Denmark, and Tschechoslowakischen Akademie der Wissen- there are records also after 1950 in the southern schaften, Prag. (Hansen and northeastern parts of Zealand Baraud, J. 1992. Col6opteres Scarabaeoidea t996). d'Europe. Faune de France 78. Soc. Linn. Lyon.

4'7 Håkan Liungberg Ent. Tidskr. 123 (2002)

Biström, O., Silfverberg, H., Rutanen, I. 1991. Abun- Sammanfattning dance and distribution of coprophilous Histerini Släktet Onthophagus Latr. är tillsammans med (Histeridae) and Onthophagus and Aphodius de närstående släktena Copris O.F.Miiller och (Scarabaeidae) in Finland (Coleoptera). Ent. Caccobius Thomson de nordligaste representa- Fenn. 2: 53-66. terna för underfamiljen Scarabaeinae, en grupp Bunalski, M. 1999. Die Blatthornkäfer Mitteleuropas. av dynglevande bladhorningar dit bl.a. Egyptens Bratislava. heliga skarab6 hör. naturvårdssammanhang Croneborg, H. 2001. Skogsbeten. En metodstudie I stär Onthophagus i eL klass för sig det zir ett från Cotland. Länsstyrelsen i Gotlands län. Livs- - miljöenheten, rapport 5, 2001. av de släkten där samtliga svenska arter är röd- -l998. Gustavsson, G. Dyngbaggar (Coleoptera: Sca- listade. En starkt bidragande orsak till detta är rabaeidae) på kustnära betesmarker i mellersta naturligtvis att alla arterna dr värmekrävande Halland. Ent. Tidskr. ll9 64-67. och i Sverige befinner sig vid eller nrira sin nord- Gyllenhal, L. 1821 . Insecta Svecica. Coleoptera, gräns. De är följaktligen känsliga inte bara för Eleuterata. Tom. I. Pars IV. Leipztg. ändringar i betesdriften och annan mänsklig på- Gzirdenfors. U. 2000. The 2000 Red List of Swedish verkan, utan också för klimatförändringar. Att Species (Rödlistade arter i Sverige 2000). AfiDa- våra arlers utbredning och status kartläggs är tabanken, Uppsala. därför angeläget. Hansen, M. 1996. Katalog over Danmarks bilier. Ent. medd. 64 (l-2): l-231. Trots att släktet Onthophagus har ett mycket Hansen, M., Liljehult, H., Mahler, V., PaIm, E. 1993. karakteristiskt utseende eir flera av arterna p.g.a. 12. tillaeg til "Fortegnelse over Danmarks biller" stor inomaftsvariation mycket svårskilda, och (Coleoptera). Ent. medd. 61: 85-113. systematiken har de senaste decennierna varit Hansen, V. 1958. Biller XX. Till:rgsbind. - Danmarks utsatt för en hel del förändringar. Landin (1951) fauna 64. Kobenhavn. uppger sex arter från Sverige: O. taurus (Schre- Hunt, J., Kotiaho, J.S., Tomkins, I.L. 1999. Dung pad ber), O. ovatus (.L.), O fracticornis (Preyssler), residence time covaries with male morphology in O. coenobita (Herbst), O. vacca (L.) och O. the Onthophagus taurus. Ecol. Ento- nuchicornis (L.). I den senaste skalbaggskatalo- mology 24: 174-180. gen (Lundberg 1995) har antalet stigit till nio, i Krell, F.-T., Fery, H. 1992. Familienreihe Lamellicor- (Scriba), joannae nia. In: Lohse, G.4., Lucht, W.H. (eds);Die Käf'er och med att O. similis O. Gol- Mitteleuropas, Band 13: 200-252. Goecke & jan och O. illyricus (Scopoli) tillkommit. De ny- Evers, Krefeld. tillkommna arternas status och utbredning har Landin, B.-O. 1957. Bladhorningar, Lamellicomia. emellertid aldrig blivit ordentligt utredd. Skill- Svensk insektfauna 9. Entomologiska Förening- naderna mellan O. fracticornis och O. similis en. Stockholm. har beskrivits på ett delvis missvisande sätt, vil- Landin, B.-O. 1959. Notes on Onthophagusfracticor- ket lett till att de ofta förväxlats i samlingar. De . nis and O. similis (Col. Scarab.). Opusc. Ent. 24: arlskiljande karaktärerna mellan O. ovatus och 215-224. O. joannae har aldrig presenterats på svenska, Lundberg. S. 1980. F1 nd av l'ör Sverige nya skalbagg- varför flerlalet exemplar av dessa arter alltjämt saner rappoflerade under åren 1978.79. Ent. gamla Tidskr. 101 (2-3): 9l-93. står under det kollektivnamnet O. ovatus. Lundberg, S. 1982. Bidrag till kännedom om svenska Och slutligen, hur O. taurus och O. illyricus skalbaggar 20. Ent. Tidskr. 103 (l):12-14. skall skiljas åt är det överhuvud taget ingen som Lundberg, S. 1995. Catalogus Coleopteron.rm Sueci- har vetat. ae. Naturhistoriska Riksmuseet. Stockholm. Syftet med denna artikel zir framför allt att Machatschke, J.W. 1969. Familienreihe Lamellicor- klargöra hur många arter vi egentligen har, och nia. In: Freude, H., Harde, K.W. & Lohse, G.A. hur de skall skiljas åt på ett säkert sätt. En utvid- (eds); Die Käfer Mitteleuropas, Band 8:215-371. gad bestämningsnyckel ges, med de viktiga ka- Goecke & Evers, Krefeld. raktärerna illustrerade. Beträffande arternas ut- Pitkänen, M & Roslin, T. 2001. Dung beetles. In: Pir bredning håller jag mig på landskapsnivå, och känen, M & Tiainen, J. (eds); Biodiversity of agri- cultural landscapes in Finland: 81-89. Birdlife, behandlar huvudsakligen ändringar gentemot Helsinki. senaste skalbaggskatalogen (Lundberg 1995).

48 Ent. Tidskr. 123 (2002) Notes on North European Onthophagus Detta eftersom vå,ra dyngbaggars utbredning mer östlig och inskränker sig till Blekinge, och status kommer att behandlas i större detalj i Öland och Gotland. Sentida lynd finns endast ett pågående arbete av Mattias Forshage (pers. från Skåne (O. joannuel. Öland tO. ovatu.\l och komm.). Jag har inte heller haft möjlighet att Gotland (båda arterna). kontrollera allt material, utan har koncentrerat O. grossepunctatus Reitter är en sydeurope- mig på att verifiera landskapsuppgifterna för de isk art med tyngdpunkten i Medelhavs-området mest kritiska arterna. Resultaten är i korthet de och de nordligaste förekomsterna i Slovakien iöljande: och sydöstra Polen. I GNM's samlingar finns ett De båda arterna O. taurus och O. illyricus tir exemplar av denna art, enligt lokaletiketten in- ytterligt snarlika, och deras artberättigande har samlat 3/8 1958 nära Kinna i Västergötland (leg. många gånger ifrågasatts. De yttre karaktärer A. Törnvall). Fyndet är synnerligen oväntade, som omnämnts i litteraturen (täckvingarnas och det rör sig utan tvekan om ett tillfälligt infört punktur och behåring) är ytterst vaga, och en- exemplar eller en ren feletikettering. dast skillnader i hangenitalierna visar att det rör O. gibbulus är ett överaskande tillägg till vår sig om två goda arter (Krell & Fery 1992). De fauna, emedan tre exemplar som tidigare be- svenska exemplaren artbestämdes dock innan stämts till O. vacca nu visat sig tillhöra denna dessa skillnader var kända, med andra ord en- art. Exemplaren härrör alla från samma lokal bart med hjälp av yttre morfologi. Härvid skulle och insamlingstillfälle (Skåne, Esperöd, juni huvuddelen av det svenska materialet tillhöra O. 1860), och några senare svenska fynd föreligger illyricus, medan några få exemplar tolkades som ej, varför arlen är att betrakta som utdöd: O. taurus. Jag har granskat huvuddelen av det O. similis och O. fracticornishar ofta föryäx- svenska materialet, och kan konstatera att så lats, delvis p.g.a. att de artskiljande karaktärerna gott som alla belägg för O. taurus i stället hänför beskrivits på ett missvisande sätt. Uppgifterna sig till O. illyricus. Det enda undantaget är ett om O. similis från Östergötland och Västergöt- exemplar i ZML, vars etikettering inte är helt land baserar sig på felbestämda exemplar av O. invändningsfri. I ljuset av artens sydliga utbred- fracticornis, varf.ör O. similis visar sig vara en ning och att en feletikettering inte kan uteslutas, mer sydlig arl, .känd endast från Skåne, Ble- anserjag attO. taurus skall strykas urden svens- kinge, Halland, Oland, Gotland och Bohuslän. I ka faunan, medan O. illyricus å andra sidan Skåne åir O. similis lokalt vanligare än O. fracti- kvarstår för Gotland och Södermanland, men cornis, men längre norrut är den sällsynt och fö- skall strykas från Skåne (det skånska exemplaret refaller vara knuten till sandmarker. är felbestämt). I senaste rödlistan (Gärdenfors Med dessa ändringar kan vi räkna nio 2000) är O. taurus rödlistad som "akut hotad" Onthophagus-arter såsom hemmahörande i den (CR, Critically Endangered), medan O. illyricus svenska faunan: O. illyricus (Scopoli), O. ovatus el bedömts (detta p.g.a. de ovannämnda oklarhe- (L.), O. joannae Goljan, O. nuchicornis (L.), O. terna om arternas status). Den korrekta rödlist- vacca (L.), O. gibbulus (Pallas), O. fracticornis ningen f'örefaller nu att vara "akut hotad" för O. (Preyssler), O. similis (Scriba) och O. coenobita illyricus, medan O. taurus kan strykas ur röd- (Herbst). Deras utbredning i stora drag framgåt listan. av det ovan skrivna, men sista ordet zir säkerli- Också O. joannae och O. ovdtus är mycket gen inte sagt, framför allt vad gäller arternas nu- svårskilda, men med hjälp av genitalkaraktärer varande utbredning och status. Åtminstone tre kan båda könen bestämmas säkert. Säkra exem- och förmodligen inte mindre än fyra av våra ar- plar av O. joannae är nu kända från Skåne, Ble- ter är att betrakta som försvunna ifrån landet, kinge. Halland. Cotland. Östergötland och Väs- även om två av dessa (O. vacca och O. coeno- tergötland, medan utbredningen för O. ovatus är bita) annu lever kvar så nära som i Danmark.

49