Jonathan Mawdsley.
A new species of the genus Strotocera Schenkling (Coleoptera: Cleridae: Tillinae) from the Baltic Amber.
Psyche 100(1-2):77-81, 1993.

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A NEW SPECIES OF THE GENUS STROTOCERA
SCHENKLING (COLEOPTERA: CLERIDAE: TILLINAE) FROM THE BALTIC AMBER
Department of Entomology
Museum of Comparative Zoology
Harvard University
Cambridge, MA 02138 USA
The genus Strotocera Schenkling contains seventeen extant species, of which two are found in southeast Asia and fifteen are generally distributed throughout sub-Saharan Africa (Corporaal 1950: 15-16; Pic 1953: 320; Ekis 1975: 11). Strotocera may be distinguished from a related complex of genera by means of the key given by Schenkling (1903: 3-4). The specific-level taxonomy of Strotocera is based at present on characters of coloration, and several specific synonymies undoubtedly exist in this genus. Noth- ing has been published on the biology of these beetles, although specimens may be found in most of the world's major museums (see Materials below).
I was recently given a poorly preserved specimen of a new species of Strotocera from the Baltic Amber which was discovered by Christopher J. Marshall (now of Cornell University) while con- ducting curatorial work in the fossil insect collection of the Museum of Comparative Zoology. Although this specimen has lost whatever coloration it may have possessed during the process of diagenesis, its structural morphology is sufficiently preserved to warrant description and preliminary comparison with that of extant species of Strotocera. Because of the extensive fracturing of the amber surrounding this fossil, it was not possible to photograph the specimen.
Manuscript received 6 April 1993.
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78 Psyche [vo~. 100
In addition to the one specimen preserved in Baltic Amber, I examined specimens of extant species of Strotocera in the collec- tions of the following institutions: The Natural History Museum (London); Institut Royal des Sciences Naturelles de Belgique (Brussels); Museum of Comparative Zoology (Cambridge, MA); and Musee Royal de L' Afrique Centrale (Tervuren). Strotocera marshalli NEW SPECIES
(Figure 1)
LENGTH: 9.7 mm (measured from frons to elytral apices). INTEGUMENT: Uniformly coarsely and densely punctate; elytra striatopunctate at base, apical third impunctate. VESTITURE: Uniformly covered with short erect setae, base of elytra with long erect setae.
HEAD: As wide as pronotum; eyes large, coarsely granulate, cov- ered with short erect setae; interocular distance 0.5 mm; eyes surrounded by a glabrous area; mandibles recurvate, finely and densely punctate dorsally; first antenna1 segment conical, finely and densely punctate.
PRONOTUM: Length 2.5 mm, width 2.0 mm; subapical depression broad, recurvate medially; pronotum proper robust, with a feeble longitudinal median sulcus; pronotal collar planate, slightly constricted.
LEGS: Preserved as fragments; coarsely and densely punctate; completely covered with short erect setae; profemora larger than meso- or meta-femora.
ELYTRA: Length 6.6 mm, transhumeral width 2.5 mm; humeri angulate; basally striatopunctate, punctures not decreasing in size towards apices; apical third impunctate; apices rounded. MATERIALS: HOLOTYPE, sex indeterminate, preserved in Baltic Amber, deposited in collection of Museum of Comparative Zoology.
ETYMOLOGY: This species is named in honor of Christopher J. Marshall, who discovered the type specimen in the amber collection of the Museum of Comparative Zoology. DIAGNOSIS: This species is similar to many species of Strotocera from Africa (such as S. convexa Hintz) with regard to its



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Mawdsley
Tigure 1. HOLOTYPE of Strotocera marshalli NEW SPECIES from Baltic ber. Length of specimen 9.7 mm.




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overall length, the structure of its profemora, the shape of the subapical depression of its pronotum, and the robustness of its pronotum proper. However, it shares at least three charac- ters with the group of species typified by the Indonesian species Strotocera grandis Schenkling: its planate pronotal collar which is only slightly constricted basally; the glabrous area surrounding its eyes; and the arrangement of its elytral punctures.
Many clerid genera, including Strotocera, share a present-day discontinous distribution which includes sub-Saharan Africa and southeast Asia (see Table 1). The most parsimonious explanation for this distribution pattern is that the ranges of these clerid genera were at one time continuous across southern Asia into Europe and Africa. The presence of tropical clerid genera such as Strotocera and Orthrius Gorham (Menier 1983: 163-165) in the Baltic Amber certainly lends weight to this hypothesis. However, the alternative hypothesis, independent evolution of generic characters in African and southeast Asian Cleridae, cannot be ruled out, particularly in the case of the poorly defined genera of the large generic complex typified by the genus Stigmatium Gray. Further studies of clerid inclusions in the Baltic Amber such as that of Winkler (1990: 371-381) may clarify these questions of clerid phylogeny and zoo- geography.
Table 1. Clerid Genera with Discontinuous Distributions between Sub-Saharan Africa and Southeast Asia.
--- -- -- -
Clerid Genus
African species
Tillodenops
Strotocera
Astigmus
Stigmatium
Phaeocyclotomus
Tenerus
Korynetes
SE Asian species
- -
1
2
4
5 0
4 1
8 8
3
- -
(Source: Corporaal 1950)




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19931 Mawdsley 81
I would like to thank F. M. Carpenter and P. D. Perkins for their helpful assistance with this project. I must also thank D. G. Furth and P. D. Perkins for reading the manuscript. Strotocera marshalli NEW SPECIES (Coleoptera: Cleridae: Til- linae) is described from a specimen preserved in Baltic Amber. A preliminary assessment of the relationships of this new species is provided. In the opinion of the author, the study of Baltic Amber fossils is essential to understanding present-day discontinuous dis- tributions in clerid genera such as Strotocera Schenkling. CORPORAAL, J. B.
1950. Coleopterorum Catalogus, Pars 23 Editio Secunda, Cleridae. W. Junk, The Hague. 373 pp.
EKIS, G.
1975. Taxonomic and nomenclatural status of clerid taxa described by Massi- miliano Spinola (1780-1857) (Coleoptera: Cleridae). Boll. Mus. Zool. Univ. Torino. 1: 1-80.
MENIER, J. J.
1983. Orthrius succini, n. sp., Cleridae Fossile de L'Ambre (Coleoptera). Revue fr. Ent. 5: 4: 163-165.
PIC, M.
1953. Neue Cleriden aus der Sammlung des Deutschen Entomologischen Instituts. Beitr. zur Ent. 3: 3: 320-322. SCHENKLING, S.
1903. Family Cleridae, Genera Insectorum (Wytsman). 124 pp. + 5 plates. WINKLER, J. R.
1990. Two new Genera of fossil Korynetinae from Baltic Amber (Coleoptera, Cleridae). Acta Univ. Carolinae. 34: 371-381.



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