France, Italy, Portugal, Spain. hornii Rivers ...
ZOOLOGISCHE MEDEDELINGEN UITGEGEVEN
DOOR
RIJKSMUSEUM
V A N NATUURLIJKE
(MINISTERIE V A N
CULTUUR, RECREATIE
HET
HISTORIE
TE
LEIDEN
E N MAATSCHAPPELIJK WERK)
Deel 51 no. 17
28 juni 1977
T H E G E N U S BOLBELASMUS B O U C O M O N T IN ASIA, W I T H N O T E S O N SPECIES O C C U R R I N G IN O T H E R REGIONS (COLEOPTERA: GEOTRUPIDAE) by
J.
K R I K K E N
Rijksmuseum van Natuurlijke Historie, Leiden W i t h 19 text-figures and one plate
ABSTRACT The
genus Bolbelasmus B o u c o m o n t is diagnosed. T h e O r i e n t a l a n d P a l a e a r c t i c species
are keyed. A checklist o f the w o r l d species a n d subspecies is given. T w o new species are described : Bolbelasmus meridionalis (Indonesia, C h i n a , T h a i l a n d , V i e t n a m ) a n d B. nativus ( T a i w a n ) . T h e other A s i a n species are discussed a n d their distribution is recorded. A subspecific d i f f e r e n t i a t i o n is suggested f o r the N o r t h A f r i c a n B. bocchus ( E r i c h s o n ) .
Although this paper mainly deals with the four East Asian species of Bolbelasmus Boucomont, I have added notes regarding species occurring elsewhere. Only pertinent references are given, as little of importance has been added to our knowledge of the O l d W o r l d forms after Boucomont (1912). Cartwright (1953) and Howden (1964, 1974) dealt with the N e w W o r l d species. I have diagnosed the genus, described two new species, and inserted them in a key to the Palaearctic and Oriental species. A l l the known species are listed, and records concerning those of Asia are given. Some serious taxonomic problems remain (specified below), the solutions to which cannot be given without studying more material. This seems not to be available. Little can be said about phylogeny, as the character states cannot, in my opinion, be interpreted phylogenetically. The dispersal between the present New and O l d W o r l d land masses seems to have occurred i n the North Pacific, the amphi-Pacific group formerly named Kolbeus being indicative of this.
278
ZOOLOGISCHE M E D E D E L I N G E N
Bolbelasmus
51
(1977)
Roucomont
Bolbelasmus B o u c o m o n t , 1911
: 335
Kolbeus B o u c o m o n t , 1911
(diagnosis, 2 spp. included), 338 (in key) ; P a u l i a n ,
40 (in k e y ) , 41
: 335
(diagnosis, 3 spp. included), 338 (in k e y ) . 1945:
(diagnosis).
Generic diagnosis. — Frons with more or less conical erect protrusion ( Palaearctic (8 spp.), Nearctic (5 spp.), and Neotropical Region (2 spp.) — total 16 species. I would not be surprised if the gap between the West Palaearctic and F a r East area would be filled in the near future. The absence of records from Sumatra, Borneo and the Malay Peninsula may be real in view of the absence or rarity of primeval open forest (the West Palaearctic species seem to prefer this type of habitat). Bionomics. — Nothing pertinent seems to be known about the Asian species, except that they are attracted to light. The European B. gallicus and unicorne are found burrowing to various hypogeic fungi, including truffles, in open oak and pine forests on various soils. They are crepuscular and/or nocturnal, and stridulate vigorously. Essentially, this is all we know about the habits of Bolbelasmus. Fabre (e.g. 1900: 38off.) has given vivid des criptions of his observations on the habits of Bolbelasmus gallicus. s
K E Y TO O L D W O R L D SPECIES OF
Bolbelasmus
Males (with more or less conical frontal protrusion) ι. Pronotal base at least medially marginate. Scutellum usually short (1/w ratio < 1.2; fig. 5)
4
— Pronotal base immarginate. Scutellum elongate (1/w ratio > 1.2), basally more or less parallel-sided (figs. 2-4) 2 2. Juxtasutural interstria of elytra raised, strongly convex. Anterolateral angle of pronotum rectangular (fig. 11) 3 — Juxtasutural interstria of elytra not raised over its entire length. Anterolateral angle of pronotum slightly acute (fig. 11). Parameres with rounded apex (fig. 8). Frontal horn between eye-canthi, base elongate, contiguous with clypeofrontal suture. Length 9-13.5 mm coreanus 3. Parameres with rounded apex (fig. 7). Frontal horn between eyes. Pronotum laterally very densely, more or less contiguously punctate (number of punctures beneath lateral foveole 15 or more, separated by less than their diameter). Length 10 mm nativus — Parameres with angulate apex (fig. 6). Frontal horn between eyecanthi. Pronotum laterally abundantly but not contiguously punctate (number of punctures beneath lateral foveole less than 15, separated by more than their diameter). Length 7-9.5 mm . . . . meridionalis 4. Ridge on basal margin of pronotum broadly interrupted laterally.
KRIKKEN,
B O L B E L A S M U S IN
ASIA
281
Usually reddish brown 6 — Ridge on basal margin of pronotum complete. Usually black . . . 5 5. Scutellum densely punctate. Frontal horn basally not dilated. Length 10-15 gallicus — Scutellum smooth or nearly so. Basal part of frontal horn strongly dilated (figs. 16, 18). Length 10-16 mm . . . bocchus (2 subspecies) 6. Frontal tubercle with bifid apex (at least in larger males; fig. 10) Length 12-12.5 mm orientalis — Frontal tubercle with simple apex 7 7. Eye-canthus rounded. Punctures of elytral striae not superficial . . 8 — Eye-canthus angulate anterolateral^ (fig. 12). Punctures of elytral striae small, superficial, scarcely affecting interstriae (fig. 13). Lateral impressions and tubercles of pronotum poorly pronounced. Frontal horn slender. Length 10-12 mm tauricus 8. Frontal horn robust (base one-third of interocular width). Distance between anterolateral angles of pronotum less than or equal to distance between lateral tubercles. Eye-canthi wide. Large species, length 12-15 mm unicornis — Frontal horn slender (base one-fourth of interocular width or less). Distance between anterolateral angles of pronotum exceeding distance between lateral tubercles. Eye-canthi narrow. Small species, length 10.5 mm nireus m
m
Females (with tranverse frontal protrusion) ι.
Pronotal base at least medially marginate. Scutellum usually short
(1/w ratio < 1.2) 4 — Pronotal base immarginate. Scutellum elongate (1/w ratio ^ 1.2), basally more or less parallel-sided 2 2. Juxtasutural interstria of elytra raised, strongly convex. Anterolateral angle of pronotum rectangular (fig. 11). Eye-canthi different . . 3 — Juxtasutural interstriae of elytra not raised over its entire length. Anterolateral angle of pronotum slightly acute (fig. 11). Eye-canthi widely arcuate in front. Length 9.5-11.5 mm coreanus 3. Eye-canthi narrowly tapering. Pronotum laterally abundantly but not very densely punctate. Length 6.5-8 mm meridionalis — Eye-canthi widely tapering. Pronotum laterally very densely, more or less evenly punctate. Length 9 mm nativus 4. Ridge on basal margin of pronotum broadly interrupted laterally. Usually reddish brown 6
282
ZOOLOGISCHE M E D E D E L I N G E N
51
(1977)
— Ridge on basal margin of pronotum complete. Usually black . . . S 5. Scutellum densely punctate. Medial elevation of frontal ridge truncate. Length 10-15 gallicus — Scutellum smooth or nearly so. Medial elevation of frontal ridge bituberculate. Length 12-16 mm bocchus 6. Eye-canthi wide. Penultimate fossorial elevation of hind leg with m
Figs.
2-5.
m
D o r s a l contours o f fore body o f
Bolbelasmus
species (males). 2,
meridionalis,
holotype ; 3, nativus, holotype ; 4, coreanus, S u - T c h u e n ; 5, orientalis, holotype. Scale lines =
ι m m ; 2, 3 : same scale ; 4, 5 : same scale.
KRIKKEN,
B O L B E L A S M U S IN
283
ASIA
F i g s . 6-19. Details o f Bolbelasmus. 6-9, left paramere, f u l l - f a c e view o f : 6, meridionalis, holotype; 7, nativus, holotype; 8, coreanus, S u - T c h u e n ; 9, orientalis, holotype. 10, frontal tubercle o f orientalis ( f r o n t a l v i e w ) . 11, left anterolateral angle o f pronotum, nativus a n d coreanus. 12, 13, left eye-canthus a n d scutellar region (dorsal view) o f tauricus, holotype; 14,
15, ditto, o f cf. nireus, $
A n t a l y a . 16,
17,
frontal horn (frontal view)
and left side
contours o f pronotum o f bocchus bocchus, S M a s c a r a ; 18, 19, ditto, o f bocchus vaulogeri, $
Sousse, Scale line w i t h f i g . 6 — 0.1
m m , w i t h 12
elements same scale.
=
0.5 m m , others =
1 mm;
same
ZOOLOGISCHE M E D E D E L I N G E N
284
51
(1977)
feebly bisinuate crest. Large species, length 12-15 mm . . . unicornis — Eye-canthi narrow. Penultimate fossorial elevation of hind leg with perfectly arcuate crest. Small species, length 9.5-10 mm . . . nireus
C H E C K L I S T OF
Bolbelasmus
SPECIES A N D SUBSPECIES
arcuatus Bates, 1887: i n (Bolboceras; lectotype in London).
