Athyreus freyi Gomes Alves (1957:671)

Carpaneto, Giuseppe M., Mignani, Roberto & Piattella, Emanuele, 2000, A Taxonomic Overview Of The Genus Pseudoathyreus Howden And Martinez, And Redescription Of Two Related Species From Southern Africa (Coleoptera: Geotrupidae: Bolboceratinae), The Coleopterists Bulletin 54 (2), pp. 239-247 : 241-246

Athyreus freyi Gomes Alves (1957:671)

Type. In Centro Zool. da Junta de Investigaçoes do Ultramar, Lisboa (not examined) .

Material Examined. 1 (unsexed) (paratype), ‘‘S. Martinho do Bilene’’ (near Macia), November 1955 ( MHNB).1?: Mozambique, Inhaca Island , 22 March1991, R.Minetti leg. (Carpaneto). 2 ?? : Mozambique, Maputo, 20 March 1991, R.Minetti leg. (Mignani). 4 ??, 1 /: South Africa, Natal, Sodwana Bay , 10 November 1984 H. & A. Howden leg. (Howden). 1?: ‘‘ Xalosi, 7­4­05’’ (handwritten label) ( SAM) .

Redescription. Size small (approximate maximum length: 11 mm; approximate maximum width: 6 mm). Habitus in figure 1. Upper surface of body shining, with sparse and short whitish setae. Colour of upperparts sometimes entirely black (2 of the 5 examined specimens from Natal), but more often light yellowish brown, marked with black as follows: entire head surface, anterior pronotal margin in middle and in narrow adjacent area, posterior part of inner carinae, with ‘‘butterfly­like’’ area extending between and over them, posterior pronotal margin, scutellum, elytral margins, large area adjacent to anterior margin of elytra (including umbone), sutural and juxta­sutural intervals, large median spot reaching elytral apex and extending laterally up to seventh interval ( Fig. 1 ). Remaining pronotal margins, anterior inner carinae, lateral foveae, tarsi, apex of tibiae, terminal spurs and external teeth of tibiae brown. Underparts entirely black except for anterior area of prosternum. A small degree of variation in extension of black mark­ ings: black spot on posterior part of inner carinae often more or less reduced. Labrum dorsally concave, not carinate, anteriorly rounded with a small median tip. Mandibles asymmetrical with two angulate lateral laminate processes on external sides. Right mandible with deep indentation before apex; left one distinctly sinuate before apex. Clypeus ( Fig. 2 ) with anterior carina regularly rising from sides to a high pyramidal tooth in middle, with anterior face nearly vertical. Clypeo­frontal carina elevated, distinctly angulate anteriorly in middle, with two lateral teeth almost as high as anterior one, and connected to anterior clypeal carina by longitudinal ridge. Frontovertex slightly concave, almost flat, rising upwards to clypeo­frontal carina, its surface with distinct and wellspaced punctures, almost absent on small discal (roughly V­shaped) area. Genae concave, almost impunctate, sharply angulate, with anterior margin almost straight. Clypeo­genal angles with careniform tubercle. Upper surface of eye extremely reduced, sunken below genal surface. Pronotum ( Fig. 2 ) entirely margined, with small superficial fossa (fovea) on each side, contiguous with anterior marginal bead behind eye. Margin between fossae gradually elevated to large, erect, pointed tubercle on midline, posterior to and contiguous with marginal bead. Anterior half of pronotum with wide concavity sloping anteriorly and edged on each side by inner carina. A median longitudinal groove extending from base of anterior tubercle to posterior pronotal margin. Inner carina formed by two unaligned fragments: anterior one short and rising to sharp, elevated angle; posterior one longer, lower, sinuate and enlarged at posterior end. Outer carina also formed by two unaligned fragments: anterior one well marked, sinuate above lateral fovea and almost reaching antero­lateral margin of pronotum; posterior one almost obsolete, flat and wider. Posterior part of pronotum, in middle, with two small, flat elevations aligned with posterior fragments of inner carinae. Surface of all carinae smooth, surface of pronotum with dense and granulate punctures, each puncture with fine seta, punctures less granulate in excavation. Along posterior pronotal margin, two multiserial rows of setae present on each side of midline. Lateral pronotal margin below fovea with sharp indentation where margin interrupted. Scutellum sunken, very elongate, almost twice as long as wide, feebly punctate. Elytral base marginate. Bead of humeral angle lacking tooth. Suture strongly carinate and enlarged. Eight striae between suture and humeral umbone: first two striae indicated by row of punctures from about apex of scutellum to basal margin of elytra, and merging together at about posterior third of elytra; eighth stria not impressed and only consisting of irregular row of punctures; all other striae distinctly impressed, irregularly punctate, each puncture bearing long, whitish seta; intervals distinctly convex, smooth and shining. Metasternum largely pyriform, irregularly and sparsely punctate, with narrow groove on midline, deeper in anterior part, finer posteriorly, with long hairs sparser in basal part. Sternites and femora covered by dense, long, whitish hair, visible from above. Fore tibia with four external teeth, size decreasing towards base; tibial spur slightly arcuate, extending approximately to end of first tarsal segment. Superior spur of hind tibia shorter than first two tarsal segments. Parameres in figures 4 and 6, genital capsule in figure 8.

Variation. The nine specimens examined do not show a significant variation in morphology because they are fundamentally uniform in clypeal and pronotal ornamentation as well as in body size. On the other hand two distinct colour patterns occur in this species: two specimens (1 male and 1 female) from Natal are entirely black.

Remarks. This species differs from P. rhodesianus by the following characters: (1) colour usually light yellowish with black markings on head, pronotum, elytra and legs ( Fig. 1 ) (sometimes entirely black); (2) clypeo­frontal carina anteriorly angulate (not straight) in the middle ( Figs. 1–2 ); (3) posterior part of pronotal inner carina distinctly separated from the anterior one (not appearing as an extension of it), narrow and distinctly elongated (not shortened and reduced to a small drop­like elevation) ( Figs. 1–2 ); (4) humerus lacking a small but distinct tooth; (5) parameres ( Figs. 4, 6 ); (6) genital capsule ( Fig. 8 ).

Distribution and Habitat. The geographical distribution of the rhodesianus group seems to be restricted to the eastern part of southern Africa (from southern Zaire to Natal, through Mozambique), while the genus is widespread from western Africa to India.

According to our present knowledge, P. freyi seems to be endemic to a restricted area along the coast from southern Mozambique to Natal: Inhaca is a well known tourist island near Maputo, the capital of Mozambique; S. Martinho do Bilene (the type locality) is an old name for a locality near Macia (258029S/338069E), at the mouth of the Limpopo on the right bank of the river; Sodwana Bay lies on the Natal coast. As for the place called ‘‘Xalosi,’’ it has not been traced on any map. However, the latter locality was quoted by Wheel­ er (1922), in the gazetteer enclosed to his checklist of Afrotropical ants, as located in ‘‘Portoguese East Africa ,’’ i.e., Mozambique, among those localities which ‘‘have not been found on any map’’. Moreover, Louw (1986), in his revision of Microcerine weevils, reported ‘‘Xalasi’’ as ‘‘not traced’’ locality. Even though there is a good probability that this mysterious site does actually occur in Mozambique, the correct spelling of its name and its location needs to be verified, together with the identification of the original collector .

On the other hand, P. rhodesianus shows an inland range from southern Zaire (W Kasai region) to Zimbabwe.

Due to the scarcity of collecting data, little is known about ecology and behaviour of these species. As stressed by Howden (1985b) for some Neotropical Bolboceratinae, bicoloured species are not only crepuscular but also fly during the day ( Howden, 1985b). Indeed, diel activity was observed in P. freyi : all five specimens from Sodwana Bay, Natal, were collected flying between 9–10 am (in litt. H. F. Howden). No detailed information has been obtained on the collecting techniques, habitat and time for the specimens collected at Inhaca.

Discussion and Affinities. Within the genus Pseudoathyreus , we preliminarily identify two phylogenetic units: – a southern African group, including P. rhodesianus and P. freyi ; – a group widespread throughout tropical Africa to the Indian subcontinent, including all the remaining species.

Such coarse subdivision is supported by several characters shared by P. rhodesianus and P. freyi :

(1) the elytra with distinctly impressed striae; this character was already point­ ed out by Howden & Martinez (1963) for P. rhodesianus and we have observed the same status in P. freyi ;

(2) the small size, not exceeding 12 mm in length and 6 mm in width; all the other species we examined are larger than 12 mm;

(3) upper surface of eyes clearly reduced; these are mostly covered by the protruding genae;

(4) the distinctive colour patterns and variation; as described above, P. rhodesianus is wholly black or brown, while P. freyi usually shows a bicoloured (black and yellow) pattern even though some entirely black specimens occur; all the other species are brown, more or less dark;

(5) the shape of male genital apparatus; differences mainly occur in the genital capsule ( Figs. 8–9 ) which shows a pair of symmetric elevations lacking in all the other species we examined; (6) the shape of clypeo­frontal transversal carina, typically V­shaped, with a small but well defined longitudinal carina extending forwards ( Figs. 2–3 );

(7) the geographic distribution extending throughout the Zambezian regional centre of endemism; the other African species occur in the Sudano­Sahelian subregion or in southwestern Africa.

However, only a taxonomic revision of the whole genus will allow us to decide if these two species warrant a subgeneric separation.

Figures

Fig. 1. Habitus of Pseudoathyreus freyi Gomes Alves, male.

Figs. 2–3. Head and pronotum of: 2) P.freyi Gomes Alves; 3) P.rhodesianus Peringuey, type.

Figs. 4–9. Pseudoathyreus freyi Gomes Alves: 4) aedeagus, antero­dorsal view; 6) aedeagus, lateral view; 8) genital capsule. P. rhodesianus Peringuey, type: 5) aedeagus, antero­dorsal view; 7) aedeagus, lateral view; 9) genital capsule.