Lithocharodes dubia, Irmler, 2024

Irmler, Ulrich, 2024, Additions to Neotropical species of the genera Lithocharodes Sharp, 1881 and Somoleptus Sharp, 1881 (Coleoptera, Staphylinidae), Contributions to Entomology 74 (1), pp. 13-34 : 13

Lithocharodes dubia sp. nov.

Figs 2a-d , 19B

Material examined.

Holotype: COSTA RICA male; Puntarenas; Osa Peninsula ; 4 km W Rancho Quemado; 8°41'36"N, 83°35'33"W; ridge forest litter; 500 m elevation; 24 VI 2001; R. Anderson leg.; KNHM CR1A01 121

Paratypes: COSTA RICA; 1 female; Guanacaste; Pitilla Biological Station ; 10°58'0"N, 85°25'0"W; 600 m elevation; Berlese leaf litter; 2 May 1995; R. Anderson leg.; KNHM CR1A95 4B .

Diagnosis.

According to the small dorsal plate of the aedeagus, L. dubia must be grouped to the L. obscura -subgroup. In contrast to both other species of the subgroup, L. obscura and L. hansoni , L. dubia has no concavely emarginate posterior margin of the head. The sclerotised edges of the orifice are similar as in L. hansoni . In the overall habitus, L. dubia resembles L. nigerrima Irmler, 2021 in size, colouration, proportion of the elytra and punctation. As the dorsal plate of the aedeagus is difficult to recognise, the taxonomic situation of the species is not clear.

Description.

Length: 4.3 mm; Colouration: black; abdominal tergites II-IV slightly lighter, brown; legs yellow-brown; antennae brown.

Head: 0.75 mm long, 0.61 mm wide; eyes moderately large, not prominent; PS:E ratio 3.6; postocular sides nearly parallel; in posterior half semi-circular; interantennal furrows short; setiferous punctation moderately deep and dense; on average, interstices between punctures at least as wide as diameter of punctures; partly wider; surface without microsculpture, polished; antennae with first antennomere elongate; approximately two thirds as long as head; second and third antennomere conical; longer than wide; combined half as long as first antennomere; following antennomeres wider than long; apically increasing in width. Pronotum: 0.87 mm long, 0.53 mm wide; widest in anterior third; 1.2 times as wide as in front of posterior angles; anterior angles widely convex; narrowed to neck; behind middle, abruptly narrower than in front; posterior sides nearly parallel; posterior angles sub-rectangular; posterior margin slightly convex; setiferous punctation deeper and denser than on head; on average, interstices between punctures half as wide as diameter of punctures; laterally partly sparser; wide mid-line impunctate; surface without microsculpture; polished. Elytra: 0.69 mm long, 0.66 mm wide; humeral angles obtuse; sides nearly parallel; posterior angles sub-rectangular; posterior margin retreated to suture; setiferous punctation deeper and denser than on pronotum; on average, interstices between punctures half as wide as diameter of punctures; partly denser; surface without microsculpture; polished. Abdomen with setiferous punctation finer and slightly sparser than on fore-body; surface without microsculpture; polished; sternite VII of male at posterior margin slightly convex with short central emargination; tergite VII of male at posterior margin nearly straight; meso-tibia with 5, meta-tibia with 2 ctenidia. Aedeagus widest in posterior half, in middle, abruptly narrowed to apex; apical part still narrower; long orifice with sclerotised inner edges; endophallus covered by moderately large spines; parameres long; bilobed; inner lobe three fourths as long as central lobe; elongate; slender; straight at base; from middle to apex curved; in basal part, three short setae; in central part with few sensillae; outer lobe transparent; half as long as inner lobe.

Etymology.

The species name derived from the same Latin word and means doubtful. It refers to the doubtful taxonomic situation of the species due to the hardly recognisable size of the aedeagal dorsal plate.

Geography.

Costa Rica.

Ecology.

Montane forest litter in May and June.

Figures

Figure 19. A. Fore-body of Lithocharodes andersoni; B. L. dubia; C. L. esmeraldae; D. L. falini; E. L. hansoni; F. L. hibbsi. Scale bars: 0.5 mm.

Figures 1 - 4. 1. Lithocharodes andersoni; 2. L. dubia; 3. L. esmeraldae; 4. L. falini. a. Aedeagus; b. Paramere; c. Sternite VII; d. Tergite VII. Scale bars: 0.5 mm (a, c, d); 0.1 mm (b).