Microlia silacea ( Erichson, 1839 )

Gusarov, Vladimir I., 2002, A revision of the genus Microlia Casey, 1910 (Coleoptera: Staphylinidae: Aleocharinae: Hoplandriini), Zootaxa 34, pp. 1-24 : 9-12

1. Microlia silacea ( Erichson, 1839) ( Figs. 19­33)

Homalota silacea Erichson, 1839: 120 .

Homalota silacea: Bland, 1865: 398 .

Dolosota (Microlia) pernix Casey, 1910: 144 .

Homalota silacea: Leng, 1920: 115 .

Homalota pernix: Leng, 1920: 115 (as synonym of H. silacea ). Atheta silacea: Leng, 1920: 119 .

Atheta (Microdota) silacea: Fenyes, 1920: 187 .

Atheta (Microdota) pernix: Fenyes, 1920: 187 (as synonym of A. silacea ). Atheta (Microdota) silacea: Bernhauer & Scheerpeltz, 1926: 635 . Atheta (Microdota) pernix: Bernhauer & Scheerpeltz, 1926: 635 (as synonym of A. silacea ). Atheta (Microdota) silacea: Leng & Mutchler, 1927: 22 .

Atheta (Microdota) pernix: Leng & Mutchler, 1927: 22 (as synonym of A. silacea ). Atheta (Microdota) silacea: Moore & Legner, 1975: 374 . Atheta (Microdota) pernix: Moore & Legner, 1975: 374 (as synonym of A. silacea ). Acrotona (Microlia) silacea: Seevers, 1978: 257 .

Acrotona (Microlia) pernix: Seevers, 1978: 257 (as valid species).

Type material. Lectotype of H. silacea (here designated):, “5462”, “ silacea Er. Am. [ Amerika] spt. [Septentrionale] Zimm. [Zimmermann]” (green label), “ Type ” (red label)”, “Zool. Mus. Berlin” ( MNHUB); paralectotypes: (with head and prothorax missing), “Americ. sept. Zimmerm. Nr. 5462” (green label), “ silacea Er. Typ. ”, “ Type ” (red label), “Zool. Mus. Berlin”; 1 specimen (with the apex of abdomen missing), “Americ. sept. Zimmerm. Nr. 5462” (green label), “ Type ” (red label), “Zool. Mus. Berlin” (all in MNHUB). The purpose of the lectotype designation is to assure correct and consistent application of the name in the future.

Lectotype of D. pernix (here designated):, “Va” (with a dot under “a”) [ Norfolk], “ Microlia pernix Csy. ”, “Casey bequest 1925”, “ Type USNM 39192” (red label) ( NMNH). The purpose of the lectotype designation is to assure correct and consistent application of the name in the future.

Additional material: UNITED STATES: North Carolina:, 2, (Sherm.) without precise locality data ( FMNH).

Diagnosis: Microlia silacea can be distinguished from other species of Microlia by the shape of the aedeagus, particularly the apical process of median lobe ( Figs. 26­29 ), by having female accessory sclerites ( Fig. 25 ) and spermatheca forming two­three coils ( Fig. 32­33 ).

Description: Length 1.8­1.9 mm. Head, elytra and abdominal segments 3­4 yellowish brown, pronotum, legs, antennal articles 1­7 and mouthparts brownish yellow, abdominal segments 5­7 and antennal articles 8­11 brown.

Head surface glossy, on disk with weak isodiametric microsculpture, puncturation fine, distance between punctures ½­1 time their diameter. Eyes 2­2.5 times as long as temples.

Pronotum strongly transverse, 1.3 times wider than head, width 0.43­0.46 mm, length 0.30­0.31mm, width to length ratio 1.5, surface glossy, with weak and poorly visible (at x70) transverse microsculpture; puncturation as on head or finer, distance between punctures 1­2 times their diameter. Elytra wider (0.56­0.59 mm) and longer (0. 41­0.43 mm, measured from humeral angle) than pronotum (pronotal length to elytral length ratio 0.71), 1.3 times wider than long, glossy, microsculpture and puncturation as on pronotum. Mesotarsus with 5 segments.

Abdominal terga glossy, with fine and poorly visible (at x70) microsculpture consisting of meshes, with fine puncturation, distance between punctures 1­3 times their diameter.

Male tergum 7 without tubercles; tergum 8 with several small tubercles in front of posterior margin ( Fig. 22 ). Posterior margin of male sternum 8 with pointed triangular lobe; some apical microsetae bifurcate ( Fig. 21 ). Aedeagus as in Figs. 26­29, 31 . Apex of median lobe with narrow process ( Fig. 29 ).

Female tergum 8 with slightly concave posterior margin ( Fig. 24 ), sternum 8 with posterior margin forming obtuse lobe ( Fig. 23 ). Females have two spine­like accessory sclerites ( Fig. 25 ). Spermatheca forming two­three coils ( Fig. 32­33 ).

Variability: In some specimens the basal abdominal segments are brown. Strength of pronotal puncturation is variable.

Synonyms. The types of Dolosota pernix and Homalota silacea are identical in external characters and genitalia. The synonymy established by Leng (1920) and Fenyes (1920) is confirmed.

Distribution: Known from Virginia and North Carolina ( Fig. 80 ).

Figures

FIGURE 80. Geographical distribution of Microlia Casey. 1 – M. silacea (Erichson); 2 – M. meticola (Casey); 3 – M. azteca (Casey); 4 – M. pentamera Gusarov, sp. nov.; 5 – M. tetramera Gusarov, sp. nov.; 6 – M. panamensis Gusarov, sp. nov.

FIGURES 26 ­ 33. Details of Microlia silacea (Erichson) (26 ­ 29, 31 – paralectotype of Homalota silacea; 30, 33 – North Carolina; 32 – lectotype of Homalota silacea). 26 – median lobe of aedeagus, lateral view; 27 – apex of median lobe of aedeagus, lateral view; 28 – median lobe of aedeagus, ventral view; 29 – apex of median lobe of aedeagus, ventral view; 30 – antenna; 31 – apical lobe of right paramere, internal view; 32 ­ 33 – spermatheca. Scale bar 0.2 mm (25, 27, 29, 31 ­ 33), 0.1 mm (26, 28, 30).

FIGURES 21 ­ 25. Abdominal segment 8 and female accessory sclerites of Microlia silacea (Erichson) (21 – paralectotype of Homalota silacea; 22, 25 – North Carolina; 23 ­ 24 – lectotype of Homalota silacea). 21 – male sternum 8; 22 – male tergum 8; 23 – female sternum 8; 24 – female tergum 8; 25 – female accessory sclerites. Scale bar 0.25 mm (21 ­ 24), 0.1 mm (25).