Phloeotribus scabricollis ( Hopkins, 1916 )

Atkinson, Thomas H., 2024, New species, new synonymy, taxonomic notes and new records of bark and ambrosia beetles from the southwestern United States and northern Mexico (Coleoptera: Curculionidae: Platypodinae and Scolytinae), Zootaxa 5424 (2), pp. 151-175 : 163-164

Phloeotribus scabricollis ( Hopkins, 1916)

Fig. 2E

Phloeophthorus scabricollis Hopkins, 1916: 656

Phthorophloeus scabricollis (Hopkins) : Chamberlin 1939: 141

Phloeotribus scabricollis ( Hopkins, 1916) : Wood 1982: 274

Phloeotribus pseudoscabricollis Atkinson, 1989: 329 new synonymy

This species was described from Indiana by Hopkins (1916). Subsequent collections have all been from the Great Lakes region of the U.S. and Canada ( Deyrup 1981; Wood 1982; Cognato et al. 2009; Douglas et al. 2013). This species breeds in Ptelea trifoliata ( Rutaceae ). Staphylea trifolia ( Staphyleaceae ), a completely unrelated plant, has been listed as a host (e.g., Wood 1982) but so far as I have been able to determine this is a mistake due to the similarity in spelling of the two names and the broad geographical overlap of the plants. I have seen no specimens labelled with this host, and have only seen it in secondary references.

Phloeotribus pseudoscabricollis was described from four specimens in two series from southern Texas without host information. Some differences from P. scabricollis were noted in the original description, but a primary consideration was the distance between southern Texas and the closest reported localities (~ 1,600 km) of P. scabricollis and the major ecological differences in the plant communities where collected. In 2008 large numbers were collected emerging from cut branches of Zanthoxylum fagara ( Rutaceae ) by E.G. Riley from southeastern Texas. This prompted me to look in populations of Ptelea trifoliata in central Texas, where large numbers were also collected.

Closer comparison of all material, including both holotypes, shows that only a single species is represented. All known localities and the host ranges of Ptelea trifoliata and Zanthoxylum fagara are shown in Fig. 2 E . Ptelea trifoliata is widely distributed in eastern North America from Southern Canada to Florida and to southern Mexico, with significant disjunct populations in Arizona and New Mexico. The host is a small tree with no known economic importance. Species of Zanthoxylum are widely distributed in the southern U.S. and in subtropical and tropical forests in Mexico. Like most phloem-feeding bark beetles, P. scabricollis is apparently not attracted to traps baited with ethanol and has not been encountered in trapping surveys ( Rabaglia et al. 2019). The lack of records from intervening areas is most likely due to the lack of directed collecting efforts.

New Records: United States: Texas: Cameron Co., Sabal Palm Grove, 25.8498 N, 97.4185 W, 31-X-2008, E.G. Riley, reared from branch of Zanthoxylum fagara * (TAMU, 100); Travis Co., Austin, Guerrero Park, 30.2428 N, 97.6952 W, 18-II-2012, Ptelea trifoliata, T.H. Atkinson (UTIC, 7); Austin, 30.2494 N, 97.6998 W, 1-V-2018, Ptelea trifoliata, T.H. Atkinson (UTIC, 14).

Figures

FIGURE 2. Distribution maps. Newly reported records are represented by stars, previously reported records by solid circles. (A) Chaetophloeus flourensiae, (B) Chaetophloeus heterodoxus, (C) Chaetophloeus sulcatus, (D) Chramesus mimosa, (E) Phloeotribus scabricollis, (F) Pseudothysanoes yucce.