Homalolinus tlanchinolensis Márquez, 2003

Márquez, Juan, 2013, Discovery of the Male of Homalolinus tlanchinolensis Márquez and Confirmation of Renda debilis (Sharp) (Coleoptera: Staphylinidae: Xantholinini) from Mexico, The Coleopterists Bulletin 67 (4), pp. 544-546 : 544

Homalolinus tlanchinolensis Márquez, 2003

Specimens Examined. “ México: Veracruz, Huayacocotla, Los Helechales, 2 km NE del entronque a Huayacocotla , N 20°37′29.1″, W 98°27′37.6, 1926 m, bosque mesófilo de montaña, trampa de intercepción de vuelo #3, 21-III a 4-IV- 2011, J. Márquez col.” (four males). Same data, except “trampa de intercepción de vuelo #2” (two females) .

Morphological Variation. The specimens agree with the diagnosis given in Márquez (2003), except for the following characters: males (n = 4) with total body length 16.0– 17.7 mm; females (n = 2) with total body length 16.2–17.3 mm; both males and females with scutellum nearly black, one male with scutellum reddish brown; pro- and mesosternum reddish brown to brown; last two abdominal segments and genital segment orange. Aedeagus pear-shaped; total length 1.32 mm; parameres asymmetrical; base of median lobe rounded; internal sac inconspicuous ( Fig. 1a–b ).

Homalolinus tlanchinolensis and H. divisus are sympatric in several places of Hidalgo and Veracruz, Mexico. Both species can be distinguished relatively easily because H. tlanchinolensis has the lateral area of the head with deep and dense punctures in the upper half and fine ones in the lower half, the scutellum is nearly black or at least reddish brown, the fifth visible abdominal segment is orange, and the base of the median lobe of the aedeagus is rounded, and the parameres are inserted near the middle of the median lobe ( Fig. 1a–b ); H. divisus has deep and dense punctures in all lateral areas of the head, the scutellum is orange or red, the anterior half of the fifth visible abdominal segment is black and the posterior half is orange, and the base of the median lobe of the aedeagus is longer, less rounded than in H. tlanchinolensis , and the parameres are inserted near the apical third of the median lobe ( Figs. 2–5 ). The differences in the aedeagi from both species are evident in spite of the considerable variation observed in specimens of H. divisus from different localities of Mexico, Guatemala, and Honduras; these differences do not correspond with differences in other morphological characters. Nevertheless, it is necessary to conduct a thorough re-analysis of many specimens of H. divisus from different geographical areas to determine if the variation in the shape of the aedeagus corresponds to several distinct species.

Figures

Figs. 1–5. 1) Ventral (a) and lateral (b) views of the aedeagus of Homalolinus tlanchinolensis. Ventral view of the aedeagus of Homalolinus divisus: 2) Typical form; 3) From Guanajuato, Mexico; 4) From Guatemala; 5) From Honduras (redrawn from Márquez 2003). Scale bar = 1 mm.