Alurnus dallieri Pic 1926

Alurnus dallieri Pic, 1926

Alurnus costalis v. Dallieri Pic, 1926: 9 (original description).

Alurnus costalis v. bipartitus Pic, 1926: 9 (original description), syn. nov.

Alurnus tricolor Uhmann, 1927: 134 (original description; primary junior homonym of A. tricolor Olivier, 1789), syn. nov.

Alurnus horni Uhmann, 1935: 90 (new substitute name for A. tricolor Uhmann), syn. nov.

Type localities. Alurnus costalis v. bipartitus: ‘Equateur’; A. costalis v. Dallieri: ‘Equateur’; A. tricolor: ‘Ecuador’.

Type material examined. Alurnus costalis v. bipartitus: HOLOTYPE: pinned, ‘ Equateur [w, hw by Pic, s] || type [yellow, hw by Pic, s] || TYPE [r, p, cb] || v. bipartitus | mihi [w, hw by Pic, s]’ (MNHN).

Alurnus costalis v. Dallieri: HOLOTYPE: pinned, ‘ Equateur [w, hw by Pic, s] || sous condition | ex Clermont [w, hw by Pic, s] || Alurnus | costalis v. | nov Dallieri | mihi [w, hw by Pic, s] || type [yellow, hw by Pic, s] || Museum Paris | Coll. M. Pic [w, p, cb] || HOLOTYPE [r, p, cb]’ (MNHN).

Remarks. PIC (1926) described two varieties, A. costalis var. dallieri Pic, 1926 and A. costalis var. bipartitus Pic, 1926, from Ecuador. UHMANN (1927) described A. tricolor from Ecuador and noted that it is similar to A. costalis Rosenberg, 1898. However, the name was preoccupied by A. tricolor Olivier, 1789, leading UHMANN (1935) to propose a new substitute name A. horni for his species. STAINES (2013) revised the genus, considered A. horni valid, retained var. bipartitus under A. costalis and raised the rank of the var. dallieri to species and placed it among taxa with pubescent pronotum and smooth elytra without costae.

Types of both Picʼs varieties have sparsely pubescent pronotum and elytra with elevated ribs and are conspecific with A. horni. The var. bipartitus has the basal half of elytra yellow and the apical part blood red, just like A. horni while var. dallieri has completely red elytra. Besides colouration, there is no other character to separate these forms. Although the two varieties were described in the same publication, because of STAINESʼ (2013) act A. dallieri has the priority according to the Principle of the first reviewer (ICZN 1999: Article 24.2). Therefore I consider A. horni and A. costalis var. bipartitus as junior subjective synonyms of A. dallieri.

As mentioned above STAINES (2013) misinterpreted A. dallieri and wrongly placed it in the key. Hence this species should replace A. horni in the key and has to be deleted from the couplet 8. In the latter key, A. costalis is separated from A. horni (= A. dallieri) and A. chapuisi Uhmann & Jolivet, 1952, a third species with pubescent pronotum and costate elytra, by the setose vertex and each elytron with six costae vs. vertex not setose and elytra with four or five costae. However, these characters are variable at least in A. dallieri, which may also have six costae on each elytron, four main and two shortened additional ones more or less visible between the second and third, and third and fourth costae, respectively. Also it has short but distinct pubescence on vertex so the main distinguishing character is the density of vestiture on pronotum, which completely covers it in A. costalis while in the two other species it is very sparse.

Alurnus dallieri is known only from Ecuador while A. costalis seems to be restricted to Colombia. ROSENBERG (1898) described A. costalis based on one specimen from Colombia (Juntas, Río Dagua) and two from Ecuador (Cachabí) and noted that the latter differ from the type in the sparsely pubescent pronotum and that the pubescence was probably rubbed off. I have not examined these two specimens but it is likely that they belong to A. dallieri due to the sparsely pubescent pronotum. STAINES (2013) published as A. costalis also three specimens from Ecuador, one without further locality data and two from Cachabí and Cachabí to Paramba. I have not examined these specimens but they most likely belong to A. dallieri as ROSENBERG (1898) mentioned specimens from the same locality having sparsely pubescent pronota.

Distribution. Ecuador (PIC 1926, UHMANN 1927).