Balleriolus alleni Sousa & Vaz-de-Mello 2023, sp. n.
Creators: name: Sousa, Rafael
name: Vaz-de-Mello, Fernando Z.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Hybosoridae
Balleriolus
Balleriolus alleni

description: Balleriolus alleni sp. n.
(Figures 1I–L, N, 4A, E, I)
Differential diagnosis. Balleriolus alleni sp. n. can be distinguished from B. howdeni sp. n., by the following combination of characteristics (B. howdeni sp. n. in parentheses): distal palpomere cylindrical (flattened); antennal scape slender (outwardly expanded); pronotum with 2 setae (lacking setae); anterior lateral area of pronotum very concave (concavity extending almost to anterior and posterior angles); pseudoscutellum elongated (rounded); elytral distal angle acuminated (rounded); protibia outer margin serrated (not serrated) (see Table 2).
Description. Holotype. Sex unknown (not dissected). Body. Length 5.5 mm; width across anterior margin of pronotum 1.9 mm. Colour. Dorsal surface brightly reddish orange; ventral surface, antennae and mouthparts slightly lighter than surface; legs yellow orange, setae yellow or yellow orange (Figure 1I–K, N). Head. Surface of frons glabrous, disc longitudinally convex and anteriorly punctate; eye-canthus narrow and rounded, extending about half length of the eye, lateral margin with 1 long seta; posterior area of clypeus with abrupt declivity, anterior area densely punctate with 2 setae diagonally parallel on each side, anterior margin slightly reflexed, emarginated in median area and with 3 setae on each side, angles slightly rounded (Figures 1I, N, 4A). Labrum transverse with 2 long lateral seta on each side, disc slightly convex, anterior margin arcuated (Figure 1K, N). Mandibles with 2 long setae on anterior area of outer face, inner margin slightly angulated, tooth acuminated (Figure 1K, N). Antennal scape slender, club elongated and laterally setose (Figure 1N). Thorax. Pronotal sulcus U-shaped, longer than wide; pronotal scar distinct; anterior median half convex; anterior angles rounded; margin adjacent to sulcus convex and outwardly expanded forming a rounded lobe on each side with 1 seta each; anterior lateral area very concave on each side, median area with 1 seta on each side; lateral margin slightly sinuated; posterior angles rounded; pseudoscutellum elongated, convex and slightly elevated, anterior area convergent and slightly coplanar to sulcus, posterior margin slightly angulated (Figures 1I, N, 4A). Scutellum wide, posterior area narrow, acute, and coplanar to elytra (Figure 1I). Elytral dorsal surface lacking setae, with small dark punctures and heterogeneous dark brown maculae; striae indistinct; distal angle acuminated; pseudoepipleure distinct and densely setose (Figures 1I–J, 4E). Mesoventrite glabrous and sinuated posteriorly. Posterior margin of metaventrite rounded; posterior margin sinuated. Legs. Profemur with sparse setae anteriorly. Outer face of protibia medially setose, setae vary in size, outer and inner margin with long setae in proximal area, outer margin with 6–7 teeth, the distal tooth longer and more rounded than others (Figure 4I). Tarsomeres cylindrical and slightly expanded anteriorly. Meso- and metafemora setose; Meso- and metatibiae lacking distinct transversal carinae; meso- and metatarsomeres with ventral setae more robust than the dorsal setae. Metathoracic wings large. Abdomen. Surface of sternites with long and scattered setae.
Type material. Holotype: Sex not determined (CEMT); PERU: Atalaya prov., 7 km NWW, Atalaya, near Sapani vill., h = 360 m, December 2016; Holotype, Balleriolus alleni sp. n., des. Sousa and Vaz-de-Mello, 2021.
Distribution. Peru: Ucayali Region, Atalaya Province, Raymondi District (Figure 6A).
Etymology. The species is named in honour of Albert Allen (Boise, Idaho, USA), who kindly sent and donated the specimen to this study.
Key to species in the Ivieolus genus group (modified from Howden and Gill 2001)
1. Maxillary palpus slender (Figures 3H, 4A, B); distal palpomere subpiriform (Figures 3H, 4A, B). Labium with 3 palpomeres visible; palpus small and cylindrical (Figure 3H). Sides of pronotum not constricted (Figures 1A, E, I, 4A, B). Posterior area of pseudoscutellum not separated from posterior margin of pronotum (Figures 1, 4A, B) (Balleriolus gen. n.)............................................................................................................................... 2
- Maxillary palpus robust (Figures 3G, 4C, D); distal palpomere piriform (Figures 3G, 4C, D). Labium with 1 palpomere visible, large and nearly spherical (Figure 3G). Sides of pronotum constricted (Figures 3A–F, 4C, D). Posterior area of pseudoscutellum separated from posterior margin of pronotum (Figures 3A–F, 4C, D) (Ivieolus Howden and Gill, 1998).................................................................................................................................................. 3
2. Distal maxillary palpomere cylindrical (Figures 1N, 4A). Antennal scape slender (Figures 1N, 4A). Anterior lateral area of pronotum very concave (Figure 1I–K, N). Pseudoscutellum elongated (Figures 1I, 4A). Protibia outer margin serrate (Figure 4I). Peru .................................................................................................................................. B. alleni sp. n.
- Distal maxillary palpomere flattened (Figures 1M, 4B). Antennal scape outwardly expanded (Figures 3H, 4B). Lateral area of pronotum concave extending almost to anterior and posterior angles (Figures 1A–C, E–H, M, 4B). Protibia outer margin smooth (Figure 4J). Brazil .................................................................................. B. howdeni sp. n.
3. Pronotum with a V-shaped sulcus in posterior median half (Figures 3A–C, 4C); pronotal construction strongly distinct, concave in distal half (Figures 3A–C, 4C)... 4
- Pronotum with a deep U-shaped sulcus in posterior median half (Figures 3D–F, 4D); pronotal construction slightly distinct, not concave in distal half (Figures 3D–F, 4D). Venezuela, Guyana ........................................... I. pseudoscutellatus Howden and Gill, 1988
4. Clypeal margin anteriorly sinuated (Figures 3A, 4C). Pronotal lobes gradually narrowed posteriorly (Figures 3A–C, 4C). Elytron with slightly impressed striae (Figure 4G). French Guiana ................................................ I. brooksi Howden and Gill 2000
- Clypeal margin anteriorly evenly arcuated. Pronotal lobes of almost uniform width to abruptly narrowed apices. Elytron basally with deeply impressed striae; Ecuador .. ... ................................................................................................. I. inflaticollis Howden and Gill, 2001
description: Published as part of Sousa, Rafael & Vaz-de-Mello, Fernando Z., 2023, Balleriolus, a new termitophilous genus of Ceratocanthinae (Coleoptera: Hybosoridae) from South America and notes on termitophily in the tribe Scarabatermitini, pp. 1377-1395 in Journal of Natural History 57 (29 - 32) on pages 1389-1391, DOI: 10.1080/00222933.2023.2248689, http://zenodo.org/record/10492238