Balleriolus alleni, Sousa & Vaz-de-Mello, 2023

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, Journal of Natural History 57 (29 - 32), pp. 1377-1395 : 1389-1391

publication ID	https://doi.org/ 10.1080/00222933.2023.2248689
DOI	https://doi.org/10.5281/zenodo.10492215
persistent identifier	https://treatment.plazi.org/id/18494973-FF89-FF8D-FDB0-20F50FCCFF45
treatment provided by	Plazi
scientific name	Balleriolus alleni
status	sp. nov.

Treatment

Balleriolus alleni View in CoL sp. n.

( Figures 1I–L, N View Figure 1 , 4A, E, I View Figure 4 )

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 View 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 View Figure 1 ). 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 View Figure 1 , 4A View Figure 4 ). Labrum transverse with 2 long lateral seta on each side, disc slightly convex, anterior margin arcuated ( Figure 1K, N View Figure 1 ). Mandibles with 2 long setae on anterior area of outer face, inner margin slightly angulated, tooth acuminated ( Figure 1K, N View Figure 1 ). Antennal scape slender, club elongated and laterally setose ( Figure 1N View Figure 1 ). 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 View Figure 1 , 4A View Figure 4 ). Scutellum wide, posterior area narrow, acute, and coplanar to elytra ( Figure 1I View Figure 1 ). 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 View Figure 1 , 4E View Figure 4 ). 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 View Figure 4 ). 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 View Figure 6 ).

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 View in CoL genus group (modified from Howden and Gill 2001)

1. Maxillary palpus slender ( Figures 3H View Figure 3 , 4A, B View Figure 4 ); distal palpomere subpiriform ( Figures 3H View Figure 3 , 4A, B View Figure 4 ). Labium with 3 palpomeres visible; palpus small and cylindrical ( Figure 3H View Figure 3 ). Sides of pronotum not constricted ( Figures 1A, E, I View Figure 1 , 4A, B View Figure 4 ). Posterior area of pseudoscutellum not separated from posterior margin of pronotum ( Figures 1 View Figure 1 , 4A, B View Figure 4 ) ( Balleriolus View in CoL gen. n.)............................................................................................................................... 2

- Maxillary palpus robust ( Figures 3G View Figure 3 , 4C, D View Figure 4 ); distal palpomere piriform ( Figures 3G View Figure 3 , 4C, D View Figure 4 ). Labium with 1 palpomere visible, large and nearly spherical ( Figure 3G View Figure 3 ). Sides of pronotum constricted ( Figures 3A–F View Figure 3 , 4C, D View Figure 4 ). Posterior area of pseudoscutellum separated from posterior margin of pronotum ( Figures 3A–F View Figure 3 , 4C, D View Figure 4 ) ( Ivieolus Howden and Gill, 1998 View in CoL ).................................................................................................................................................. 3

2. Distal maxillary palpomere cylindrical ( Figures 1N View Figure 1 , 4A View Figure 4 ). Antennal scape slender ( Figures 1N View Figure 1 , 4A View Figure 4 ). Anterior lateral area of pronotum very concave ( Figure 1I–K, N View Figure 1 ). Pseudoscutellum elongated ( Figures 1I View Figure 1 , 4A View Figure 4 ). Protibia outer margin serrate ( Figure 4I View Figure 4 ). Peru.................................................................................................................................. B. alleni View in CoL sp. n.

- Distal maxillary palpomere flattened ( Figures 1M View Figure 1 , 4B View Figure 4 ). Antennal scape outwardly expanded ( Figures 3H View Figure 3 , 4B View Figure 4 ). Lateral area of pronotum concave extending almost to anterior and posterior angles ( Figures 1A–C, E–H, M View Figure 1 , 4B View Figure 4 ). Protibia outer margin smooth ( Figure 4J View Figure 4 ). Brazil.................................................................................. B. howdeni View in CoL sp. n.

3. Pronotum with a V-shaped sulcus in posterior median half ( Figures 3A–C View Figure 3 , 4C View Figure 4 ); pronotal construction strongly distinct, concave in distal half ( Figures 3A–C View Figure 3 , 4C View Figure 4 )... 4

- Pronotum with a deep U-shaped sulcus in posterior median half ( Figures 3D–F View Figure 3 , 4D View Figure 4 ); pronotal construction slightly distinct, not concave in distal half ( Figures 3D–F View Figure 3 , 4D View Figure 4 ). Venezuela, Guyana........................................... I. pseudoscutellatus Howden and Gill, 1988 View in CoL

4. Clypeal margin anteriorly sinuated ( Figures 3A View Figure 3 , 4C View Figure 4 ). Pronotal lobes gradually narrowed posteriorly ( Figures 3A–C View Figure 3 , 4C View Figure 4 ). Elytron with slightly impressed striae ( Figure 4G View Figure 4 ). 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 View in CoL