Arixyleborus guttifer ( Schedl, 1955 )

Smith, Sarah M., Beaver, Roger A. & Cognato, Anthony I., 2020, Taxonomic Changes For Indo-Malayan Ambrosia Beetles (Coleoptera: Curculionidae: Scolytinae: Xyleborini), The Coleopterists Bulletin 74 (1), pp. 37-40 : 38

Arixyleborus guttifer ( Schedl, 1955) , status restored

Xyleboricus guttifer Schedl 1955: 297 .

Arixyleborus guttifer (Schedl) : Schedl 1958: 145.

Hulcr and Cognato (2013) placed Xyleboricus guttifer in synonymy with Arixyleborus scabripennis (Blandford) , stating that the holotype of A. guttifer had elytral sculpture identical to A. scabripennis , except that the pubescence was completely abraded. We compared the holotype (in Natural History Museum, London, UK) and a series of A. scabripennis from Brunei Darussalam, East and West Malaysia, and Thailand with the holotype (in Naturhistorisches Museum) and a series of six unabraded specimens of A. guttifer from Papua New Guinea collected by B. Jordal. The specimens of A. guttifer are slightly more elongate (mean length: width ratio 2.36 in A. guttifer vs. 2.29 in A. scabripennis (n = 5 for each species). When not abraded, the pronotal disc of A. guttifer bears long, fine, semi-appressed hairs, compared to A. scabripennis that bears shorter, slightly coarser, more erect hairs. The scutellum of A. guttifer is slightly concave and the rim slightly raised; in A. scabripennis , it is flat without a raised margin. The rows of interstrial tubercles on the elytral disc anterior to the declivity are smaller, shorter, and less sharply pointed in A. guttifer than in A. scabripennis . The interstrial vestiture of A. guttifer consists solely of long, fine hairs. In A. scabripennis , declivital interstria 1 bears 1 or 2 rows of short, very coarse, erect setae; interstriae 2–4 have a single row of similar setae; the median row of setae become more hair-like in the outer interstriae but always shorter than those of A. guttifer ; interstriae 1–3 or 1–4 also have an irregular row of very short, pointed setae on each side of the median row. In view of these differences, we remove A. guttifer from synonymy with A. scabripennis and reinstate it as a distinct species.