Ceratoxenus inflatus Moreno & Zilberman, 2024

Moreno, Carlos & Zilberman, Bruno, 2024, Revalidation of the termitophilous genus Ceratoxenus Mann and description of two new species from the Neotropical region (Coleoptera: Staphylinidae: Aleocharinae: Corotocini), Zootaxa 5474 (1), pp. 35-49 : 41-42

Ceratoxenus inflatus Moreno & Zilberman sp. nov.

( Figs. 4 , 5 , 6B, E )

Diagnosis: The species is recognized by the larger and closely spaced lateral projections at frons; by the rounded triangular medial projection, overtaking the level of frontal elevations; gena elevated, broadly rounded, forming a longitudinal carina behind eyes; pronotum with anterior impression shorter and noticebly narrower than posterior, and with anterior margin arcuated.

Head. Gena somewhat smooth, broadly elevated behind eyes; head surface finely punctuate; lateral projections at frons larger and closely spaced; medial process roundely projected. Long bristles absent on vertex ( Figs. 4C , 6B,E ). Antenna with antennomere 1 cylindrical, with almost same length of antennomeres 2–4 combined; 2–4 longer than wide, subequal in length; 5–8 shorter than previous, slightly longer than wide, all subequal in length; 9– 10 slightly shorter than previous, subquadrate; 11 conical. Second maxilar palpomere broadly rounded and inflated at apex. Postmentum longer than wide occupying more than half of total head length,, slightly longer than gula, entirely covered by long bristles.

Thorax. Pronotum slightly broader on posterior region; pronotum light-brown with lateral margins darker; anterior impression shorter and noticeably narrower than posterior, and with anterior margin strongly arcuate, bearing long bristles marginally; lateral margins parallel with long bristles sparsely distributed ( Figs. 4C , 6E ). Elytra elongate, wider on posterior region; light-brown, outer margin darker. Legs with pro- and mesocoxae transverse; metacoxa triangular. Tibia slightly longer than femur, covered with long and thick bristles along entire length; outer margins of tibia slightly convex, and inner margin straight; pro-, meso-, and metatarsi increasing in length.

Abdomen. As described to genus. Male unknown.

Material examined. HOLOTYPE. Female. GUYANA. “TOPOTYPE”; “Kartabo, British Guiana, 13: III: 1924”; “Coll. by, A.Emerson, #24.50 [field number]”; “FMNHINS [ Field Museum of Natural History ] 4518561”.

Etymology. The epithet is derived from Latin, inflatus , essentially meaning “inflate”, in allusion to the bloated elevated gena, and to the conspicuously rounded lateral projections of head. Noun in masculine.

Remarks. The specimen studied contains the Emerson’s label “24.50” dated “ 13.III.1924 ”, and seemingly several termitophiles were collected by him in this date in different nests of Nasutitermes guyanae . The specimen here studied was not referenced in Emerson's synonyms paper, but he mentioned one specimen labeled as "24.61" as " Xenopelta cornuta " from this same date and locatity. Probably, these two specimens belong to the same species ( C. inflatus ), and based on these data we deduce that the host of C. inflatus is Nasutitermes guyanae , as this species was the only termite with termitophiles Emerson (1935) recorded at that particular place and date. It is noteworthy that the author erroneous synonym would stand along with any likely output, since there is no possibility of any of the abovementioned specimens belong to the genus Xenopelta . For comparison with other species, please see the other remarks above.

Biology. Probably Nasutitermes guayanae (see remarks section).

Distribution. Guyana —Kartabo.

Figures

FIGURE 4. Ceratoxenus inflatus Moreno and Zilberman sp. nov. Holotype. Habitus lateral (A), dorso-lateral (B), dorsal (C), and labels (D).

FIGURE 5. Ceratoxenus inflatus Moreno and Zilberman sp. nov. Holotype.Habitus ventral, head and thorax (A), and abdominal sternites II–V (B).

FIGURE 6. Comparative external morphology of head and thorax among Ceratoxenus species: C. tricornis Mann, 1923 (A, D), C. inflatus sp. nov. (C, E), and C. akerata sp. nov. (C, F). White arrows point to the lateral horns, yellow arrows point to the gena with a distinctive carina in C. inflatus and C. akerata, and uncarinated in C. tricornis, while cyan arrows point to the medial projection between lateral horns.