Balleriolus gen. n.

(Figures 1A–N, 2 A–E, 3 E, 4 A, B, E, F, H, I, M, N, 5B, C)

Type species. Balleriolus howdeni sp. n. (here designated).

Differential diagnosis. Balleriolus gen. n. morphologically resembles Ivieolus Howden and Gill, 1988 . On the pronotum both genera have a deep U- or V-shaped sulcus on the median posterior area, but Balleriolus gen. n. can be distinguished by the following combination of morphological characteristics ( Ivieolus morphology in parentheses): mandibles with 1 apical tooth (Figures 1M, N, 3H) (2 distinct apical teeth, Figure 3G); maxillary palpus slender (robust), distal palpomere subpiriform (Figures 1M, N, 3H, 4B) (piriform, Figure 3B, C, G); labium with 3 palpomeres (Figure 3H) (1 palpomere, Figure 3G), palpus small and cylindrical (Figure 3H) (large and nearly spherical, Figure 3G); sides of pronotum not constricted (Figures 1, 4A, B) (medially constricted, Figures 3A–F, 4C, D); posterior area of pseudoscutellum not separated from posterior border of pronotum by a margin (Figure 4A, B) (separated from posterior margin of pronotum, Figure 4C, D) (see Table 2).

Description. Body. Length 4.5–5.5 mm; width 1.5–1.9 mm; body form elongated. Head. Clypeus wide, lateral margin slightly rounded and contiguous with the gena, junction slightly rounded (Figure 1M, N); anterior area of mandibles, labrum and palps extending anteriorly to clypeus anterior margin. Mandibles with 1 tooth, anteriorly sclerotised (Figures 1M, N, 3H). Maxillae with 3 slender palpomeres; distal palp subpiriform (Figures 1M, N, 3H, 4B). Mentum small and slightly convex (Figure 3H); labial palpus with 3 small and cylindrical palpomeres (Figure 3H). Antennae with 8 antennomeres; scape slightly flattened, longer than funicle (antennomeres III–V, Figure 1M, N), proximal area narrow and sinuated; pedicel cylindrical; antennomere III smaller than IV–V; club composed by 3 antennomeres, distal lamella convex and smaller than proximal and medial lamella, medial lamella slenderer than others (Figures 1M, N, 3H, 4A, B). Thorax. Median posterior area of pronotum with a large and deep inverted U-shaped sulcus delimiting the pseudoscutellum; posterior area of pseudoscutellum convergent and not separated from posterior margin of pronotum (Figures 1, 4A, B). Legs. Procoxa subcontiguous, conical (Figure 3H); protibia with 2 acute outer teeth; distal tooth slightly unciform; spur indistinct (Figure 4I, J); tarsomeres setose laterally, cylindrical and slightly expanded distally (Figure 4I, J); tarsomeres I and V longer than II–IV; tarsal claws simple and symmetrical. Meso- and metacoxae contiguous; meso- and metafemora slender; meso- and metatibia with 2 long and simple spurs; metatarsomeres with ventral setae more robust than the dorsal setae. Abdomen. Visible sternites conical (Figures 1F, G, 2B, C).

Etymology. The genus is named after Dr Alberto Ballerio, who has dedicated many years to the study of the taxonomy and systematics of Ceratocanthinae . The gender of the name is masculine.