Andrahomanus Pic, 1903

Kejval, Zbyněk & Cz, Domažlice, 2010, Taxonomic revision of the genus Andrahomanus (Coleoptera: Anthicidae), Acta Entomologica Musei Nationalis Pragae 50 (1), pp. 167-188 : 169-171

Andrahomanus Pic, 1903

Andrahomanus Pic, 1903: 98 . Type species: Andrahomanus luteipes Pic, 1903 ; fixed by monotypy.

Redescription. Body small to medium size (2.6–4.3 mm). Head with frontoclypeal sulcus fine but distinct; antennal insertion exposed and clearly visible; neck short and thick, always well differentiated from head; eyes small to medium-sized; last maxillary palpomere small, subtriangular.

Pronotum with distinct apical flanged rim (collar) and basal margin distinctly bordered by a thin, well-defined sulcus originating at lateral foveae. Prosternal area beneath coxae well sclerotized and extended posteriorly as a distinct sclerite; posterior margin of this sclerite moderately emarginate and distinctly angulately produced medially ( Fig. 50 ). Mesosternum triangular, with lateral margins nearly straight, its anterior angle separated from anterior margin of mesothorax by very narrowly joined mesepimera ( Fig. 48 ); intercoxal process of mesosternum fully separating mesocoxae. Lateral margins of mesepisterna simply connected (not raised) with mesepimera, bare, without distinct fringe of setae. Mesoscutellum triangular, bluntly pointed posteriorly. Metendosternite with short stalk, arms narrow and obsolete ventro-lateral projections/lamina. Elytra rather convex, mostly strongly declivous at scutellar area towards base, postscutellar impression and elytral humeri indistinct; apical notches in males absent; sutural striae absent. Posterior wings strongly reduced to absent (all known species are flightless and probably apterous).

Penultimate tarsomere rather simply cylindrical (not flattened/bilobed) in metatarsi, with terminal tarsomere articulated apically; paired terminal spurs well developed.

Abdominal sternum III without foveae immediately behind metacoxae, its intercoxal process truncate apically, bordered only laterally in ventral view ( Fig. 49 ). Male sternite VIII modified, with a pair of posteriorly projecting prongs ( Figs. 3 , 9 , 13 , 20 , 24 and 33 ); paired prongs more or less tightly joined medially, latero-basal plates small and less conspicuous. Male tergite VIII forming single sclerite ( Figs. 4 , 10 , 14 , 21 , 25 and 34 ). Male segment IX (spiculum) rather robust, clearly bifurcate apically, with a pair of apical sclerites ( Figs. 5 , 11 , 15 , 22 , 26 and 35 ).

Aedeagus with tegmen clearly divided into apical portion (formed by fused parameres) and basal piece; median lobe strengthened by simple, rod-like, sclerotized apodeme, gonopore situated rather in basal piece of aedeagus, near apodeme. Female ovipositor without apparent styli, conspicuously setose ( Fig. 18 ).

Sexual dimorphism. Males rarely with modified metatibiae and/or abdominal sternum VII ( Figs. 2 , 7, 8 and 32 ). Females of the presently known species do not display any unique sexual characters.

Immature stages. Unknown.

Biology. The life history of Andrahomanus is essentially unknown. Based on the label data, specimens have been collected by sifting reeds, grass, leaf litter and flood debris at a river bank, by shore washing, by using pitfall traps (with faeces, banana or meat bait), by sweeping in grasslands, and a single specimen was taken from old baboon dung.

Distribution. Madagascar, Namibia, South Africa, Botswana and Mozambique ( Fig. 51 ).

Relationships. Andrahomanus belongs in the tribe Formicomini Bonadona, 1974 , as suggested by the combination of three major characters: i) mesepisterna simply connected with mesepimera, their bare margins not raised; ii) intercoxal process of abdominal sternum III truncate and incompletely bordered in ventral view ( Fig. 49 ); iii) male abdominal sternite III modified, with distinct posteriorly projecting prongs. Other important characters of Andrahomanus are as follows: iv) basal sulcus of pronotum distinct both dorsally and laterally, reaching as far as lateral foveae; v) anterior angle of mesosternum separated from anterior margin of mesothorax by narrowly touching mesepisterna; vi) posterior wings reduced (all known species are flightless and probably apterous); vii) metafemora simple, lacking subapical protrusion on inner side; viii) male abdominal sternite VIII modified, paired prongs of sternite VIII more or less tightly joined medially, paired latero-basal plates rather small; ix) male tergite VIII forming single sclerite; x) male segment IX (spiculum) with a pair of distinct apical sclerites; xi) gonopore situated in basal portion of aedeagus (phallobase) near basal apodeme; xii) ovipositor rather short and wide, without apparent styli and conspicuously setose.

Andrahomanus shares most of the above mentioned characters with Chileanthicus , which is known to occur in Chile, Madagascar and Australia ( KEJVAL 2009). At least four of the characters (v, viii–x) appear to be primitive and suggest, along with the Gondwanian distribution, the rather basal position of these two genera within the Formicomini . The shared unique morphology of the ovipositor (xii) can be regarded as a synapomorphy supporting their close phylogenetic relationship (monophyly). Andrahomanus differs from Chileanthicus by the simple metafemora (lacking distal dent-like protrusions on the inner side) and the position of the primary gonopore in the basal portion of the aedeagus (mostly near the apex of the median lobe in Chileanthicus ).

As for the other genera of the Formicomini , Stenidius LaFerté-Sénectère, 1847 displays the primitive characters of Andrahomanus (v, viii–x) and a similar body form (in apterous species), but it differs mainly by a reduced basal sulcus of the pronotum (slightly indicated dorso-medially to absent) and a slender ovipositor with well-developed styli (see KEJVAL 2002, 2006). Anthelephila Hope, 1833 , the most derived member of the tribe, differs from Andrahomanus in many respects, mainly by medially widely-joined mesepimera and a slender ovipositor with well developed styli (see KEJVAL 2003). It also displays a reduced, laterally indistinct basal sulcus of the pronotum and more conspicuous sexual dimorphism. Males of most species can be easily recognized by modified fore legs and abdominal sternum VII, and the structure of male abdominal segment VIII is typically more complex (the sternite is differentiated into five discrete parts, the tergite is composed of two sclerites). However, these male characters are not stable and in some species may resemble those found in Andrahomanus (see KEJVAL 2007).

Figures

Figs. 44–50. 44 – Andrahomanus luteipes Pic, 1903, holotype, labels. 45–46 – A. particularis (Pic, 1932), lectotype (male): 45 – labels; 46 – head and pronotum in dorsal view. 47 – A. ovaliceps sp. nov, holotype (female), head base and pronotum in dorsal view. 48–50 – A. sabulicola sp. nov., paratype (male): 48 – meso- and metathorax; 49 – intercoxal process of abdomen; 50 – procoxal cavities in cranial view.

Figs. 1–6. Andrahomanus crassicornis sp. nov., holotype (male): 1 – antenna; 2 – sternum VII; 3 – sternite VIII in dorsal view; 4 – tergite VIII; 5 – segment IX; 6 – aedeagus in ventral (right) and lateral (left) view. Scale = 0.2 mm: A – Fig. 6; B – Fig. 3; C – Fig. 5; D – Figs. 2, 4; E – Fig. 1.

Figs. 7–12. Andrahomanus luteipes Pic, 1903, holotype (male): 7 – apex of metatibia; 8 – sternum VII; 9 – sternite VIII in dorsal view; 10 – tergite VIII; 11 – segment IX; 12 – aedeagus in ventral (left) and lateral (right) view. Scale = 0.2 mm: A – Fig. 12; B – Figs. 8, 10; C – Fig. 11; D – Fig. 7; E – Fig. 9.

Figs. 13–18. Andrahomanus opacus sp. nov. 13–17 – holotype (male): 13 – sternite VIII in dorsal view; 14 – tergite VIII; 15 – segment IX; 16 – aedeagus in ventral view; 17 – aedeagus in lateral view. 18 – paratype (female), ovipositor. Scale = 0.2 mm: A – Fig. 13, 16, 17; B – Fig. 14, 15; C – Fig. 18.

Figs. 19–23. Andrahomanus particularis (Pic, 1932), lectotype (male): 19 – antenna; 20 – sternite VIII in dorsal view; 21 – tergite VIII; 22 – segment IX; 23 – aedeagus in ventral (right) and lateral (left) view. Scale = 0.2 mm: A – Fig. 20; B – Fig. 23; C – Figs. 21, 22; D – Fig. 19.

Figs. 24–30. Andrahomanus sabulicola sp. nov. 24–27 – holotype (male): 24 – sternite VIII in dorsal view; 25 – tergite VIII; 26 – segment IX; 27 – aedeagus in ventral (left) and lateral (right) view. 28 – paratype (male, Punda Maria sands), prong of sternite VIII. 29–30 – non-type (male, Tswalu Nature Reserve): 29 – prong of sternite VIII; 30 – apical portion of aedeagus in ventral view. Scale = 0.2 mm: A – Fig. 29; B – Figs. 24, 27, 30; C – Fig. 25; D – Fig. 26; E – Fig. 28.

Figs. 31–36. Andrahomanus scholaris sp. nov., holotype (male): 31 – antenna; 32 – sternum VII; 33 – sternite VIII in dorsal view; 34 – tergite VIII; 35 – segment IX; 36 – aedeagus in ventral (right) and lateral (left) view. Scale = 0.2 mm: A – Figs. 31, 34; B – Fig. 32; C – Fig. 35; D – Fig. 36; E – Fig. 33.

Fig. 51. Distribution of Andrahomanus Pic, 1903.