Hymenorus bifurcatus, Campbell, J. M., 2014

Campbell, J. M., 2014, An unusual suite of sexual characters in three new species of Hymenorus (Coleoptera, Tenebrionidae, Alleculinae) from Guatemala and Mexico, ZooKeys 415, pp. 295-309 : 298-299

Hymenorus bifurcatus sp. n. Figs 7-9, 15, 16, 20

Description.

This species is almost indistinguishable from Hymenorus balli and Hymenorus excavatus based on non-sexual characters. Only the slight variations in non-sexual characters are described below; full descriptions are given for the male and female characters.

Length 7.9-8.8 mm. Eyes moderately separated dorsally; OI 23 to 27 and of female 28 to 31. PI 72 to 78; basal fovea of pronotum slightly more elongate than in Hymenorus balli and Hymenorus excavatus , extending from base to near middle of disc. Pronotal punctures angularly impressed throughout.

Metatarsus with basal segment subequal to or slightly longer than segments 2-4 combined.

Male. Anterior tarsus with rudimentary lobe on venter of second segment and pubescent pad on venter of first segment. Posterior femora evenly convex on ventral margin; without carina on outer side of ventral margin. Anterior tarsal claws each with more than 20 teeth (Fig. 3). Fifth ventrite highly modified (see Figs 7, 8), with small, evenly curved process projecting ventrally from middle of disc; apex of process shallowly bifurcate; disc broadly, shallowly impressed behind median process; apical margin broadly convex. Lobes of eighth sternite (Fig. 20) broad, strongly sinuate and curved medially; apex of lobes narrowly rounded; inner sides of lobes broadly, deeply, concavely impressed. Lobes of ninth sternite (Fig. 20) short, narrow, with apical margin moderately narrowly rounded. Apicale (Figs 15, 16) triangular with sides evenly narrowed from base to narrowly rounded apex; penis as in Hymenorus balli .

Female. Anterior tarsal claws each with 7-10 teeth. Apical portion of fifth abdominal ventrite narrowly impressed. Ninth tergite (Fig. 9) broad, almost arrowhead shaped with sides widened from truncate apical margin, then abruptly narrowed to base.

Types.

Holotype, male, with labels as follows: GUAT, Border of depts. of Sololá and Chimaltenango, nr. Los Robles, IX-12-1965, 6000', JM Campbell/ HOLOTYPE, ♂ Hymenorus bifurcatus, desig. 2013, JM.Campbell The specimen is deposited in the CNCI.

Paratypes. Males 16, females, 17.

GUATEMALA: Quezaltenango: Tzanjoyan, 3 km SE Zunil, 2300 m, XI.1.1965, JMC (CNCI, JMCC) 5. Sacatepéquez: Finca Florencia, 24.VI.1993, JMC (JMCC) 2. San Marcos: 20 km S San Marcos, 4500 ft, IX.4.1964, JMC (JMCC) 1; 22 km S San Marcos, IX.3.1965, JMC (JMCC) 1. Border between Sololá and Chimaltenango: nr. Los Robles, IX.12.1965, 6000 ft, JMC (CNCI, JMCC) 27.

Etymology.

This species is named bifurcatus in recognition of the small, bifurcate process near the middle of the male fifth ventrite.

Remarks.

This species is almost identical to the sympatric species Hymenorus balli in all external characters except for the lack of a carina on the venter of the posterior femora of the males. The process on the male fifth visible ventrite (Figs 7-8) is somewhat similar to that of Hymenorus balli except that it is much smaller and the apical margin of the bifurcate lobes are narrow and shallowly impressed. The lobes of the male eighth sternite (Fig. 20) are very different from those of Hymenorus balli ; each lobe is broad, spoon-shaped with the apical margin narrowly convex. The deep, concave impression on the inner side of each lobe is unique within the genus. Females may be distinguished by the very different shape of the ninth tergite (compare Figs 6, 9, and 12).

This species was collected by beating dead leaves of recently cut trees, by beating composit shrubs, and from an arboreal bromeliad.