Dolichosoma lineare ( Rossi, 1794 )

Gimmel, Matthew L. & Mayor, Adriean J., 2019, On the North American Species of Dolichosoma Stephens and Psilothrix Küster (Coleoptera: Melyridae: Dasytinae: Dasytini), The Coleopterists Bulletin 73 (2), pp. 395-407 : 404-406

Dolichosoma lineare ( Rossi, 1794) ( Figs. 11 , 12 )

Lagria linearis Rossi 1794: 92 . For additional synonymy, see Constantin (2007) and Mayor (2007).

Dolichosoma tenuiforme Horn 1880: 150–151 . Type locality: “ Texas ” [probably in error, see below]. Type : MCZ (holotype). New synonymy.

Type Material. Holotype ( MCZ), female, labeled “Dimethylhydantoin- \ formaldehyd \ Water soluble // Tex. // D. \ tenuiforme \ Horn [handwritten] // HoloTYPE \ 3548 [red label] // MCZ TYPE \ 35354 [red label]”.

Notes. We here propose the synonymy of Dolichosoma tenuiforme Horn with the European D. lineare , the former apparently being based on a mislabeled specimen originating from Europe. We examined specimens of D. lineare from Czech Republic (Mutěnice, 6. 1940, Ing. Kouřil ( NMPC); Fig. 11 ), and these are a close match to the Horn type in habitus ( Fig. 12 ) and the following characters: pronotum extremely elongate, about 1.7X as long as wide; pronotum lacking erect, black setae; elytron acutely pointed at apex; elytron with 2–3 weak carinae. The other Western Palearctic species, Dolichosoma simile (Brullé, 1832) , has erect black setae laterally on the pronotum, rounded elytral apices, and the elytra are devoid of carinae (see Liberti 2009 and Constantin and Liberti 2011 for more details and illustrations). Characters of the third Old World species of the genus, Dolichosoma indicum Pic, 1923 , are unknown.

Horn (1880) admitted the similarity of D. tenuiforme to D. lineare in his original description (“This species resembles the figure given by Duval of the European D. lineare ”), but apparently did not examine European specimens directly. Horn reported that the single specimen was given to him by a “Miss H.C. Cook of New York City”. We were unable to trace this person, and the true origin of the type specimen remains a mystery.

Distribution. Dolichosoma lineare is a common, widespread species in the Palearctic, occurring from Great Britain and Spain in the west to Eastern Siberia and Kazakhstan in the east ( Mayor 2007). The genus Dolichosoma and any of its available species names should be omitted from North American faunal lists and considered endemic to the Palearctic region.

Figures

Fig. 11. Dolichosoma lineare, dorsal view, specimen from Czech Republic (Mutěnice). Scale bar = 1.0 mm.

Fig. 12. Holotype (MCZ) of Dolichosoma tenuiforme. A–C) Dorsal, left lateral, and frontal views, respectively, D) Labels. Images © Museum of Comparative Zoology, Harvard University.