Obrium trilobatum, Zubarán, 2020

Zubarán, Gastón E., 2020, The genus Obrium Dejean, 1821 (Coleoptera: Cerambycidae: Cerambycinae Obriini) in Argentina: new species, distributions and host plant, Zootaxa 4732 (4), pp. 556-564 : 560-561

Obrium trilobatum sp. n.

( Figs. 2C , 3 )

Description. Male holotype. Integument mostly yellowish-brown brown, except the following darker brown areas: frontal area; base and apex of escape; two longitudinal bands on each side of pronotum, fused by transverse band on anterior margin; pedicel, and apex of antennomeres; apex of femora; meso- and metasternum; elytral setae-bearing punctures and bands.

Elytral dark bands disposed as follows: first wide, placed behind scutellum slightly descending from suture to lateral margin; second on anterior third, slender, strongly oblique from sides to suture, anterolaterally fused to first band; third and fourth bands fused laterally, delimiting a trilobed area common to both elytra; third wide, irregular, placed after middle; fourth curved, in both elytra, forming semicircle (convexity directed backward).

Elytra widened toward apical half.

Holotype measurements (in mm): maximal width of the pronotum: 1.14; length of prothorax: 1.20; humeral width: 1.32; maximal width of elytra: 1.62; elytral length: 3.72; total length: 5.64.

Type Material. ARGENTINA: Jujuy: Libertador General San Martín , 3-IV-1992 (L), Di Iorio leg., 1 specimens Holotype ( MACN) , 1 specimens Allotype ( MACN) ; Salta: Jakúlika, 40 km west of Aguas Blancas , Malaise trap., Porter leg., 1 specimens Paratype ( ODI) .

Host plant: Cissus tweedieana (Baker) (dead vine).

Taxonomic discussion: The new species is similar to Obrium cordicolle Bates, 1870 , in which the elytra also bear dark-rimmed setae-bearing punctures, but the two last elytral bands make up a large transverse-oval ring also touching the suture ( Hovore and Chemsak 1980: fig 10), while in O. trilobatum the third band at the irregular edges, and does not come together in the suture. ( Hovore & Chemsak 1980: fig. 10). It is also similar to Obrium quadrifasciatum Zajciw, 1965 bears dark punctures on the elytra, and has a fourth band curved as in O. trilobatum , but the second band is disposed in a different pattern.

Figures

FIGURE 2. General aspect of the species of Obrium in Argentina: a. Obrium trifasciatum; b. Obrium multifarium; c. Obrium trilobatum sp. n.; d. Obrium vicinum. Scale bar = 5mm.

FIGURE 3. Geographic distributions of the species of Obrium in Argentina: O. bifasciatum (white squares); O. cicatricosum (white circles); O. mimicum sp. n. (black star); O. trilobatum sp. n. (black triangles); O. trifasciatum (black circles).