Badelina pygidialis ( Thomson, 1878 )

Ratcliffe, Brett C., 2014, A Review Of The Neotropical Genera Badelina Thomson, 1880, Balsameda Thomson, 1880, Guatemalica Neervoort Van De Poll, 1886, And Heterocotinis Martínez, 1948 (Coleoptera: Scarabaeidae: Cetoniinae: Gymnetini), The Coleopterists Bulletin 68 (2), pp. 241-262 : 245-247

Badelina pygidialis ( Thomson, 1878) ( Figs. 5–8 )

Gymnetis pygidialis Thomson 1878: 12 (original combination). Holotype male at MNHN, examined. Type locality: “ Brazil ”.

Description. Length 22.2–29.1 mm; width across humeri 13.8–17.6 mm. Color reddish brown to yellowish brown with black punctures on dorsal surface; head, pronotum, and elytra velutinous. Venter an enamel yellowish brown with black punctures. Head: Surface with punctures small, sparse. Clypeus with apex subtruncate to truncate, apex weakly reflexed. Eyes small, interocular width 6.0–6.5 transverse eye diameters. Antenna with 10 antennomeres, club distinctly longer than antennomeres 2–7 in both sexes. Pronotum: Surface with punctures small to large, ocellate, sparse. Sides with slender marginal bead, bead usually not reaching anterior or posterior angles. Elytra: Surface with punctures small to mostly large, sparse, ocellate, becoming crescent shaped behind weak apical umbones. Apices at suture subacutely produced. Pygidium: Surface in both sexes with transverse, vermiform strigae, becoming sparsely punctate in apical fourth to one-third, setigerous; setae short, dense, tawny. In oblique view, with feeble, longitudinal ridge at center; in lateral view, profile in both sexes nearly flat in basal two-thirds, convex in apical third. Venter: Setae long, brown and black mixed. Mesometasternal process, in lateral view, protuberant, subparallel to ventral axis of body ( Fig. 6 ), rounded in ventral view. Abdominal ventrites 1–5 in both sexes nearly smooth in central third, lateral thirds with sparse, moderately large, crescent-shaped punctures. Legs: Protibia slender, weakly tridentate in both sexes. Parameres ( Figs. 7–8 ): Form subrectangular in caudal view; apices broadly lanceolate, curving inwards, and with subapical, stout, spine-like tooth on lateral edge.

Distribution. Badelina pygidialis is known primarily from the Atlantic coastal forest region of southeastern Brazil. The single Goiás record is further inland to the west.

Locality Records. 67 specimens from ADMC, BCRC, BMNH, CASC, CMNH, DEIC, FMNH, MCZC, MGFT, MHNG, MNHN, MZSP, RMNH, UFRJ, USNM, and ZMHU. BRAZIL (67). ESPIRITO SANTO (28) : Rio Bonito , No data. GOIÁS (1) : Jatahy. RIO DE JANEIRO (8) : Mendez, No data. NO DATA (30).

Temporal Distribution. March (4). Nearly all of the specimens available for study are from old collections and have little or no collecting data.

Diagnosis. Badelina pygidialis is distinguished by its velutinous, brown pronotum and elytra, each with small, black spots ( Fig. 5 ), whereas B. aterrima is completely black on the pronotum and elytra ( Fig. 1 ). I questioned whether B. aterrima was merely a melanistic form of B. pygidialis , but I never found any intergrades of body color or pattern as is usually seen in other gymnetine species that have melanistic morphs. I completely immersed several specimens of B. aterrima in ethanol for a lengthy period to see if there might be any underlying color or spot pattern typical of B. pygidialis that would become apparent upon being wetted, but there was nothing other than black.

Although the parameres of B. aterrima and B. pygidialis are similar ( Figs. 3–4 and 7–8 ), they do differ. In lateral view, the length of the basal piece is different between the two species. In B. pygidialis , the basal piece is proportionately longer, as measured against the length of the parameres, than in B. aterrima ( Figs. 8 and 4 ). And in caudal view, the subapical spine on each paramere is more slender in B. pygidialis than the much broader spine seen in B. aterrima ( Figs. 7 and 3 ). Because of the differences in the genitalia and the totally disparate color forms that have no intergrades, I maintain B. pygidialis and B. aterrima as two separate species.

Badelina pygidialis is remarkably similar to Gymnetis punctipennis Burmeister ( Fig. 9 ) in form of the parameres and overall gestalt (velutinous brown pronotum and elytra with black spots), but B. pygidialis is a larger and more robust beetle, has the black spots on the elytra subequally spaced, and its mesometasternal process is, in lateral view, slender and projecting forwards and only slightly downwards. In G. punctipennis , the body form is smaller and more slender, the spots on the elytra are larger and usually coalesce into large spots behind the humerus and especially in front of each apical umbone, and the mesometasternal process is, in lateral view, large, subrectangular, and projecting downwards at about a 40° angle.

Natural History. Nothing is known of the life history of these beetles.

Figures

Figs. 5–8. Badelina pygidialis. 5) Habitus; 6) Mesometasternal process, lateral view; 7–8) Parameres.

Figs. 1–4. Badelina aterrima. 1) Habitus; 2) Mesometasternal process, lateral view; 3–4) Parameres.

Fig. 9. Gymnetis punctipennis.