Gorhamium, Nascimento & Bocakova, 2024

Nascimento, Elynton Alves & Bocakova, Milada, 2024, Phylogenetic analysis reveals a new net-winged beetle genus of Eurrhacini (Coleoptera, Lycidae) from the Pacific slopes of Central America and Ecuador, ZooKeys 1204, pp. 241-259 : 241-259

publication ID

https://doi.org/ 10.3897/zookeys.1204.114932

publication LSID

lsid:zoobank.org:pub:F5134CC6-A83C-48B6-A1EA-235E6858D5CB

DOI

https://doi.org/10.5281/zenodo.11505165

persistent identifier

https://treatment.plazi.org/id/E48A6CB9-FB20-5286-B758-6BEEA6FB4F65

treatment provided by

ZooKeys by Pensoft

scientific name

Gorhamium
status

gen. nov.

Gorhamium gen. nov.

Type species.

Gorhamium bidentatum sp. nov. (by present designation).

Diagnosis.

Gorhamium gen. nov. can be distinguished from other Eurrhacini by the combination of the following characters: a) elytra (Fig. 2 A – C View Figure 2 ) with nine longitudinal costae (4 costae in Haplobothris ); b) pronotum (Fig. 3 A, B View Figure 3 ) wider than long (elongated in Calocladon ); c) median areola on pronotum slenderly lenticular (slightly wider in Cladocalon and Atlanticolycus); d) male antennomere 3–10 flabellate (Fig. 4 B, C View Figure 4 ); e) aedeagus with each paramere projected ventrobasally into a slender, medially curved process (d 1, Fig. 6 C View Figure 6 ), sometimes joining at midline forming an annular bridge (d 3, Fig. 6 G View Figure 6 ) (also present in Calocladon , Cladocalon , and Atlanticolycus). Among unique features of Gorhamium gen. nov. belong: a) base of phallus pointed anchored-shaped (inverted mushroom-shaped), with arcuate arms and a pointed tip (a 1, Fig. 6 E, F View Figure 6 ), while the base of phallus of Cladocalon and Atlanticolycus is flat, or rounded (a 2, Fig. 6 A View Figure 6 ); b) median portion of phallus extending ventrally into oval opening (b, Fig. 6 C View Figure 6 ); c) dorsal edge of phallus hooked (c, Fig. 6 D, G View Figure 6 ); d) internal sac membranous with minute spines distally (e, Fig. 6 D, G View Figure 6 ); e) parameres shorter than 2 / 3 of phallus (while the parameres are almost as long as phallus in Atlanticolycus); f) base of parameres semicircular in cross-section (flattened / ribbon-like in Cladocalon ); g) apex of parameres denticulate, provided with one or two coarse teeth; h) female genitalia with valvifers as long as coxites and styli combined (Fig. 6 H View Figure 6 ).

Description.

Body length: 5.5–6.4 mm, width across the humeri: 1.2 mm. Head partly covered by pronotum from above. Labrum small, mandibles slender, arcuate (Fig. 4 A View Figure 4 ). Maxillary palps 4 - segmented, gradually widened distally, palpomere 1 (= P 1) at least 3 × shorter than P 2, P 2 longest of all, ~ 2 × longer than P 4, P 3 1.5 × shorter than P 4, terminal palpomere securiform, apex obliquely rounded (Fig. 4 A View Figure 4 ). Terminal palpomere of labial palps securiform. Pronotum somewhat trapezoidal, with anterior margin produced forward, posterior margin 1.4 × wider than median length; lateral margins divergent posterad, with anterior 2 / 3 almost straight, convergent anteriorly, posterior angles acute; posterior margin bisinuate, medioposterior process almost triangular (Fig. 3 A, B View Figure 3 ); median longitudinal carina on pronotum bifurcating in anterior third, forming very slender, lenticular areola. Scutellum square, apex minutely emarginate medially (Fig. 3 A View Figure 3 ). Elytra subparallel-sided, slender, 4 × longer than humeral width (Fig. 2 A – C View Figure 2 ). Each elytron with nine longitudinal costae (4 primary costae and 5 less elevated secondary costae), primary costae 2 and 4 strongly elevated; intercostal intervals with a row of irregular reticulate cells, secondary costae 3 and 4 absent posteriorly. Anterior thoracic spiracles small, tubulate. Legs compressed, trochanters almost triangular (Fig. 4 A View Figure 4 ), as long as third of femur, tibiae straight, their spurs small, covered by pubescence, tarsomeres 1–4 lobed.

Male. Eyes medium-sized to large, eye diameter 1.3–1.7 × longer than interocular distance. Antennae reaching beyond elytral midlength, antennomeres 3–10 flabellate, antennal branches flattened, antennomere 1 (= A 1) stout, A 2 small, transverse, A 3 slightly (1.15–1.3 ×) shorter than A 4, A 4 – A 10 subequal in length. Lamellae arise basally, lamella of A 3 slightly longer than antennomere body, remaining lamellae considerably longer. Abdominal sternum VIII widely emarginated distally (Fig. 5 C, F View Figure 5 ), emargination shallow, as deep as ¼ of sternum length. Sternum IX elongate, 3.5 × longer than wide (Fig. 5 A, E View Figure 5 ), widest in distal quarter, proximal half narrow with lateral margins convergent. Phallus with ventromedial oval opening (b, Fig. 6 C, G View Figure 6 ), base of phallus pointed anchored-shaped, or inverted mushroom-shaped (a 1, Fig. 6 E, F View Figure 6 ); distal portion of phallus rod-like, apex clavate, dorsal margin hooked (c, Fig. 6 D, G View Figure 6 ); internal sac membranous with minute spines distally (e, Fig. 6 G View Figure 6 ), sometimes also medially. Parameres at most as long as 2 / 3 of phallus, base of parameres almost semicircular in cross-section; each paramere projected basally in a thin ventral, medially arched, process (d 1, Fig. 6 C View Figure 6 ), sometimes joining medially in a ring-like bridge (d 3, Fig. 6 G View Figure 6 ); parameral apex denticulate, provided with one or two coarse teeth. Phallobase slightly asymmetrical, distorted, moderately arched ventrally.

Female. Eyes small, interocular distance 1.3 × longer than eye diameter, antennae serrate (Fig. 2 B View Figure 2 ). Terminal sternum ( IX) simple (Fig. 5 D View Figure 5 ), spiculum gastrale rudimentary, triangular. Ovipositor with valvifers 1.3 × longer than coxites (Fig. 6 H View Figure 6 ).

Etymology.

The genus is named in honor of H. S. Gorham, the author of chapters on Malacodermata in Biologia-Centrali Americana ( Gorham 1880, 1881, 1884), where he described many genera and species of Eurrhacini and Calopterini . The gender is neuter.

Distribution.

Panama, Ecuador.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Lycidae