Halobrecta Thomson, 1858

Gusarov, Vladimir I., 2004, A revision of the Nearctic species of the genus Halobrecta Thomson, 1858 (Coleoptera: Staphylinidae: Aleocharinae) with notes on some Palaearctic species of the genus, Zootaxa 746, pp. 1-25 : 2-7

Halobrecta Thomson, 1858

( Figs. 1–65 )

Halobrecta Thomson, 1858: 35 (type species Homalota puncticeps Thomson, 1852 , by monotypy).

Halobrectha: Thomson, 1861: 49 (as valid genus; incorrect subsequent spelling).

Glaphya Mulsant & Rey, 1873: 172 (as subgenus of Dinaraea Thomson, 1858 ; type species Dinaraea pubes Mulsant & Rey, 1873 , by monotypy).

Halobrechta: Mulsant & Rey, 1875: 35 (as valid genus; incorrect subsequent spelling).

Atheta (Halobrecta) : Fenyes, 1920: 185 (as valid subgenus).

Glaphya: Fenyes, 1920: 185 (as synonym of Atheta ( Halobrecta )).

Exatheta Cameron, 1920: 265 (type species Exatheta cingulata Cameron, 1920 , by subsequent designation (Blackwelder 1952)).

Atheta (Halobrecta) : Bernhauer & Scheerpeltz, 1926: 621 (as valid subgenus in subtribe Athetina Casey, 1910 ).

Glaphya: Bernhauer & Scheerpeltz, 1926: 621 (as synonym of Atheta ( Halobrecta )).

Exatheta: Bernhauer & Scheerpeltz, 1926: 681 (as valid genus in subtribe Schistogeniina Fenyes, 1918).

Atheta (Halobrecta) : Scheerpeltz, 1934: 1600 (as valid subgenus).

Halobrecta: Blackwelder, 1952: 179 (as valid genus).

Glaphya: Blackwelder, 1952: 170 (as synonym of Halobrecta ).

Exatheta: Blackwelder, 1952: 163 (as valid genus).

Halobrecta: Benick & Lohse, 1974: 219 (as valid genus in tribe Callicerini Lohse, 1969 ).

Halobrecta: Moore & Legner, 1975: 434 (as valid genus).

Halobrecta: Seevers, 1978: 121 (as valid genus in subtribe Xenotae Seevers, 1978 (nomen nudum )).

Halobrecta: Sawada, 1985: 108 (as valid genus in Coprothassa series).

Exatheta: Sawada, 1985: 108 (as synonym of Halobrecta ).

Halobrecta: Lohse, 1989: 219 (as valid genus in tribe Athetini ).

Halobrecta: Ashe in Newton, Thayer, Ashe & Chandler, 2000: 369 (as valid genus in subtribe Athetina Casey, 1910 ).

Diagnosis. Halobrecta is distinguished from other athetine genera by the combination of the following characters: body parallel­sided; anterior margin of labrum straight; sensilla a of epipharynx long; antennal article 2 longer than article 3, articles 7–10 transverse; ligula long, parallel­sided, with narrow base and slightly split apically ( Fig. 6 ); labial palpus with setae and present ( Fig. 6 ); pronotum slightly transverse, 1.1–1.2 times as wide as long, with microsetae directed anteriorly along anterior half of midline, and posteriorly along posterior half of midline; in lateral portions of the disc microsetae directed laterally (Type III, Benick & Lohse 1974) ( Fig. 14 ); pronotal macrosetae long; pronotal hypomera fully visible in lateral view; medial macroseta of mesotibia thin, as long as tibial width; mesothoracic process narrow ( Fig. 15 ); posterior margin of elytra emarginate; tarsal formula 4­5­5; metatarsal segment 1 longer than segment 2; single empodial seta longer than claws; abdominal terga 3–5 with transverse basal impression; posterior margin of female tergum 8 with comb of scattered tiny projections ( Figs. 20 , 39 ); median lobe of aedeagus without athetine bridge, apex of paramere long and narrow, medial lamellae of internal sac absent; copulatory piece with pointed apex ( Figs. 30 , 41 , 62 ) and without sclerotized suspensoria; spermatheca short, not divided into distal and proximal portions, with large umbilicus ( Figs. 32 , 51 ).

Halobrecta differs from other littoral aleocharines with the same tarsal formula ( Adota Casey, 1910 , Psammostiba Yosii & Sawada, 1976 , Pontomalota Casey, 1885 , Tarphiota Casey, 1894 ) in having a different type of pronotal pubescence ( Fig. 14 ); the posterior margin of the elytra emarginate; the posterior margin of the female tergum 8 with a comb of scattered tiny projections ( Figs. 20 , 39 ); the median lobe without the athetine bridge ( Figs. 25, 28 ); the paramere with a long apex ( Figs. 36 , 50 ) and a short spermatheca with a large umbilicus ( Figs. 32 , 51 ).

Description. Length 2.9–3.9 mm, pronotal width 0.53–0.66 mm. Body parallelsided, dark brown, with legs, basal or all antennal articles, and mouthparts yellowish brown to yellow.

Head transverse; eye length to temple length ratio 0.7–1.2; infraorbital carina complete. Antennal article 2 longer than article 3, article 4 elongate, 5 elongate or subquadrate, 6 subquadrate or transverse, 7–10 transverse, apical article without coeloconic sensilla, as long as articles 9 and 10 combined. Labrum ( Fig. 1 ) transverse, with straight anterior margin. Epipharynx ( Fig. 2 ) with long sensilla a, with three pairs of small marginal setae, medial field with 32 pores, lateral rows with two pores each, anterolateral groups with three pores each, transverse row with six pores, posterolateral groups with three–four pores each, with one medial proximal pore on each side and two lateral proximal pores. Mandibles ( Figs. 3–5 ) broad, right mandible with a small medial tooth; velvety patch of dorsal molar area not visible at 400x. Maxilla ( Figs. 8–11 ) with galea projecting slightly beyond apex of lacinia; apical lobe of galea covered with numerous fine and short setae; internal margin of galea with long subapical setae ( Fig. 9 ); distal comb of lacinia is divided into isolated groups of 5 and 2 closely placed spines ( Figs. 10–11 ), middle portion produced medially and covered with numerous fine setae ( Figs. 10–11 ), ventral surface of lacinia with a marginal group of 4 strong setae ( Fig. 10 ), dorsal surface of lacinia with a row of 18 weak setae ( Fig. 11 ). Labium as in Figs. 6–7, 12 ; ligula long and parallel­sided, with narrow base, slightly split apically ( Fig. 6 ); medial area of prementum with 2 pores and 12 pseudopores, lateral areas each with two asetose pores, single setose pore and 9–10 pseudopores ( Fig. 6 ). Hypopharyngeal lobes as in Fig. 7 . Labial palpus with setae and present ( Fig. 6 ). Mentum ( Fig. 12 ) with concave anterior margin.

Pronotum ( Fig. 14 ) slightly transverse, 1.1–1.2 times as wide as long, with microsetae directed anteriorly along anterior half of midline, posteriorly along posterior half of midline, and laterally in lateral portions of the disc (Type III, Benick & Lohse 1974) ( Fig. 14 ); macrosetae long; hypomera fully visible in lateral view. Meso­ and metasternum as in Fig. 15 , mesosternal process narrow, extending about 3/5 length of mesocoxal cavities, metasternal process short, mesosternum and mesosternal process not carinate medially; relative lengths of mesosternal process: isthmus: metasternal process in ratio of about 3:1:1; mesocoxal cavities margined posteriorly; mesocoxae contiguous. Medial macroseta of mesotibia thin, as long as tibial width. Tarsal segmentation 4­5­5, metatarsal segment 1 longer than segment 2 ( Fig. 17 ). One empodial seta, longer than claws ( Fig. 16 ). Posterior margin of elytra emarginate. Wings fully developed.

Abdominal terga 3–5 with moderate basal impressions. Tergum 7 is as long as tergum 6. Punctation on terga 6–7 finer and slightly sparser than on terga 3–5. Tergum 7 with wide white palisade fringe. Posterior margin of female sternum 8 with comb consisting of tiny projections ( Fig. 21 ). Posterior margin of female tergum 8 with irregular comb of scattered projections ( Fig. 20 , 39 ) (in some males this comb is also present but may consist of just a few projections).

Median lobe of aedeagus without athetine bridge ( Figs. 25, 28 ), internal sac without medial lamellae ( Figs. 62–65 ); copulatory piece with pointed apex ( Figs. 30 , 62, 64 ) and without sclerotized suspensoria; paramere with long and narrow apex ( Figs. 33–36 ); spermatheca short, not divided into distal and proximal portions, with large umbilicus ( Figs. 32 , 51 ).

Type species. Homalota puncticeps Thomson, 1852 , by monotypy ( Thomson 1858).

Discussion. Halobrecta is usually placed in the tribe Athetini but it lacks the athetine bridge of the median lobe which is considered as an autapomorphy of Athetini ( Seevers 1978; Muona 1987; Newton et al. 2000) although this character is also present in the tribes Lomechusini Fleming (1821) and Falagriini Mulsant & Rey (1874). The lack of the athetine bridge in Halobrecta may suggest that it belongs to Oxypodini Thomson (1859). Another character traditionally used to distinguish between the aleocharine tribes is the tarsal formula (e.g., Lohse 1974). In Halobrecta it is 4­5­5 and supports the placement of the genus in Athetini . However there are examples of changes in tarsal formula even within a genus ( Gyronycha Casey, 1894 ( Seevers 1978) , Microlia Casey, 1910 (Gusarov 2002a)). In addition to lacking the athetine bridge, Halobrecta is similar to some Oxypodini in having the apex of the paramere long; the spermatheca short with a large umbilicus; the posterior margin of the elytra emarginate; the ligula bisetose, long and narrow, split only at the very apex. The tribal placement of Halobrecta cannot be resolved until the phylogeny of Athetini and Oxypodini is analyzed.

According to a recent review of the British intertidal beetles ( Hammond 2000) Halobrecta includes at least four valid species, all of them recorded from the British Isles: Ha. algae ( Hardy, 1851) , Ha. flavipes Thomson, 1861 , Ha. princeps ( Sharp, 1869) and Ha. algophila ( Fenyes, 1909) . Two species from Singapore were described by Cameron (1920) in the genus Exatheta Cameron, 1920 ( E. cingulata and E. consors ) and subsequently transferred to Halobrecta and synonymized with each other by Sawada (1985, 1987). Pace (1999) described Halobrecta discipula from Chile. I am aware of an additional species of Halobrecta ( AUSTRALIA: ɗ, Victoria (FMNH); GREECE: ɗ, 5 specimens (sex undetermined), Kérkira (J.Sahlberg); ɗ, Elevsís (J.Sahlberg) (FMNH); ITALY: 18 specimens (sex undetermined), Friuli, Lignano, 25.v.1929 (A.Gagliardi); ɗ, 1 specimen (sex undetermined), Fiumicino, 7.vi.1898 (FMNH); MACEDONIA: ɗ, Vardar (FMNH); YUGOSLAVIA: 5 specimens (sex undetermined), Sutorina (Paganetti); ɗ, Ψ, Sutorina near Castelnuovo; ɗ, 2 specimens (sex undetermined), Castelnuovo (Hummler) (FMNH)). This species differs from the other four species in the shape of the median lobe ( Figs. 64– 65 ) and may be conspecific with Ha. halensis Mulsant & Rey, 1873 described from the coast of Languedoc ( France).

Figures

FIGURES 1 – 5. Mouthparts of Halobrecta sp. aff. algae (Hardy) (female, Grado, Italy). 1 — labrum; 2 — epipharynx; 3 — left mandible, dorsal view; 4 — left mandible, ventral view; 5 — right mandible, dorsal view. Scale bar 0.1 mm.

FIGURES 6 – 12. Mouthparts of Halobrecta sp. aff. algae (Hardy) (female, Grado, Italy (6 – 11 )) and Ha. sp. cf. halensis Mulsant & Rey, 1873 (female, Lignano, Italy (12 )). 6 — prementum; 7 — hypopharynx; 8 — right maxilla, ventral view; 9 — right galea, ventral view; 10 — right lacinia, ventral view; 11 — right lacinia, dorsal view; 12 — mentum. Scale bar 0.1 mm (6 – 7, 9 – 12), 0.2 mm (8).

FIGURES 13 – 17. Details of Halobrecta sp. aff. algae (Hardy) (female, Grado, Italy). 13 — right antenna; 14 — pronotum; 15 — meso­ and metathorax; 16 — left metatarsal segment 5 and metapretarsus, anterior view; 17 — right metatarsus, posterior view. Scale bar 0.1 mm (16), 0.2 mm (13, 17), 0.4 mm (14 – 15).

FIGURES 18 – 21. Abdominal segment 8 of Halobrecta algophila (Fenyes) (male lectotype (18 – 19) and female paralectotype of At. algophila (20 – 21 )). 18 — male tergum 8; 19 — male sternum 8; 20 — female tergum 8; 21 — female sternum 8. Scale bar 0.2 mm.

FIGURES 22 – 29. Aedeagus of Halobrecta algophila (Fenyes) (male lectotype of At. algophila (22 – 25), and male from the environs of Bolinas, California (26 – 29 )). 22, 27 — apex of median lobe, parameral view; 23, 26 — apex of median lobe, parameral view; 25, 28 — median lobe, lateral view; 24, 29 — apex of median lobe, lateral view. Scale bar 0.1 mm (22, 24, 27, 29), 0.2 mm (23, 25, 26, 28).

FIGURES 30 – 36. Genitalia of Halobrecta algophila (Fenyes) (male lectotype (30 – 31, 33 – 36) and female paralectotype of At. algophila (32 )). 30 — details of retracted internal sac, abparameral view; 31 — details of retracted internal sac, lateral view; 32 — spermatheca; 33 — left paramere, view from the side facing the median lobe; 34 — left paramere, marginal view; 35 — left paramere, view from the side opposite to the median lobe; 36 — apex of left paramere, marginal view. Scale bar 0.1 mm (32, 36), 0.2 mm (30 – 31, 33 – 35).

FIGURES 37 – 40. Abdominal segment 8 of Halobrecta flavipes Thomson (male (37 – 38) and female paralectotypes Atheta pocahontas Casey (39 – 40 )). 37 — male tergum 8; 38 — male sternum 8; 39 — female tergum 8; 40 — female sternum 8. Scale bar 0.2 mm.

FIGURES 41 – 44. Aedeagus of Halobrecta flavipes Thomson (male from Oskarshamn, Sweden (41 – 42), and male paralectotype of Atheta pocahontas Casey (43 – 44 )). 41, 43 — median lobe, parameral view; 42, 44 — apex of median lobe, parameral view. Scale bar 0.1 mm (42, 44), 0.2 mm (41, 43).

FIGURES 45 – 48. Aedeagus of Halobrecta flavipes Thomson (males, from Oskarshamn, Sweden (45 – 46), and lectotype of Atheta pocahontas Casey (47 – 48 )). 45, 47 — median lobe, lateral view; 46, 48 — apex of median lobe, lateral view. Scale bar 0.1 mm (46, 48), 0.2 mm (45, 47).

FIGURES 49 – 51. Genitalia of Halobrecta flavipes Thomson (male (49 – 50) and female paralectotypes of Atheta pocahontas (51 )). 49 — details of retracted internal sac, lateral view; 50 — apex of left paramere, marginal view; 51 — spermatheca. Scale bar 0.1 mm (50 – 51), 0.2 mm (49).

FIGURES 52 – 55. Abdominal segment 8 of Halobrecta algae (Hardy) (male lectotype (52 – 53) and female paralectotype of Homalota puncticeps Thomson (54 – 55 )). 52 — male tergum 8; 53 — male sternum 8; 54 — female tergum 8; 55 — female sternum 8. Scale bar 0.2 mm.

FIGURES 56 – 61. Genitalia of Halobrecta algae (Hardy) (male lectotype (56 – 60) and female paralectotype of Homalota puncticeps Thomson (61 )). 56 — median lobe, parameral view; 57 — apex of median lobe, parameral view; 58 — median lobe, lateral view; 59 — apex of median lobe, lateral view, 60 — apex of left paramere, marginal view; 61 — spermatheca. Scale bar 0.1 mm (57, 59 – 61), 0.2 mm (56, 58).

FIGURES 62 – 65. Details of Halobrecta sp. aff. algae (Hardy) (male, Grado, Italy (62 – 63 )) and Ha. sp. cf. halensis Mulsant & Rey, 1873 (male, Lignano, Italy (64 – 65 )). 62 — median lobe with everted internal sac, parameral view; 63 — median lobe with everted internal sac, lateral view; 64 — median lobe with partially everted internal sac, parameral view; 65 — median lobe with partially everted internal sac, lateral view. Scale bar 0.2 mm.