Pseudosynarmostes, Ballerio, 2008
|
publication ID |
https://doi.org/ 10.5281/zenodo.5395397 |
|
persistent identifier |
https://treatment.plazi.org/id/03E98E1C-FF85-FFFD-FF14-02E5BF87C169 |
|
treatment provided by |
Marcus |
|
scientific name |
Pseudosynarmostes |
| status |
gen. nov. |
Genus Pseudosynarmostes View in CoL n. gen.
TYPE SPECIES. — Pseudosynarmostes mitsinjo n. sp.
ETYMOLOGY. — From Ancient Greek ΨΕΥΔΟς (false) and Synarmostes , because the appearance of the beetle when rolled up is very similar to that of Synarmostes . The gender is masculine.
DISTRIBUTION AND HABITAT. — Madagascar, see under individual species for more details.
DIAGNOSIS. — Pseudosynarmostes n. gen. can easily be distinguished from all other known genera of Ceratocanthinae by the following combination of characters: 1) head with a deep furrow between the tip of fore margin and the vertical part of clypeus, which bears a distinct sexually dimorphic process; 2) antennae with first segment of club unusually expanded basally and oriented longitudinally ( Fig. 13F View FIG ); 3) female protibiae sharp and S-shaped ( Fig. 13B View FIG ); 4) female protibiae, when the beetle is rolled up, are not completely visible, but only a small portion is visible at sides ( Fig. 12B View FIG ); 5) mesotibiae having only one apical spur; and 6) a likely hint of genal suture visible on head.
DESCRIPTION
Small Ceratocanthinae , body dorsally shiny, ventrally alutaceous; setose; “rolling up” coaptations perfect; winged but possibly flightless.
Head wide (W/L ratio = 1.75), subrectangular, fore margin forming a very obtuse angle (about 145°, excluding apical acute process) in the middle, scarcely protruding forward and with apex slightly protruding in a small acute setose process sexually dimorphic ( Fig. 10A, B View FIG ), both sides of the process smooth and very slightly curved, not reflexed upward; genae aligned with fore margin, protruding outwards, forming a rounded right angle with genal canthus; genal canthus relatively narrow, straight and complete, touching the occipital area; dorsal ocular area small, dorsal interocular area about 10-11 times the maximum width of the dorsal ocular area, ventral ocular area large; head surface plane, with variable punctures, transversal striae and pubescence, a transverse line just before the gena (genal suture?).
Pronotum distinctly wider than long (W/L ratio = 2), slightly wider than elytra; fore margin finely beaded at middle and feebly bisinuate; fore angles slightly but distinctly protrudent forward, subtruncate; sides not beaded, obtusely rounded; base very finely beaded at middle; pronotal surface regularly convex, uniformly sculptured and setose.
Scutellum large, wider than long (W/L ratio = 1.5), sides proximally subparallel and notched by elytral articular process, then convergent to form a triangle with acute apex and sides slightly curved inward. Apical portion of mesepisterna hardly visible from above, distinctly smaller than elytral articular process.
Elytra slightly longer than wide (W/L ratio = 0.91), apical 4th regularly rounded (dorsal view), apex slightly re-entering inward (lateral view); elytra regularly convex without forming a distinct pseudoepipleuron; elytral suture very feebly raised, sutural stria extremely narrow and approaching to suture; inferior sutural stria present, although very finely impressed, delimiting a small marginal elytral area, with irregular surface sculpturing; striated articular area narrow, visible in lateral view, made of 5 or 6 striae; humeral area rounded, lacking a distinct humeral callus; elytral articular process normally developed, smooth and shiny.
Apical vertical extremity of clypeus short and transversely deeply grooved in a sexually dimorphic way, medially the groove is setose and notched upwards by the acute process of apex of head and downwards by a setose sexually dimorphic process ( Fig. 10A, B View FIG ). Labrum relatively narrow and short, bearing several long setae. Distal epipharynx ( Fig. 11H View FIG ) subrectangular, longitudinally divided by a sharp strong anterior median process; pariae distinctly raised with respect to the haptolachus; median brush and corypha absent; apical fringe made of long fine setae, absent in the middle. Labium ( Fig. 11E View FIG ) ventrally flat, deeply emarginated in the middle, emargination regularly narrow-U-shaped; labial palpi (including palpiger) 4-jointed, 1st joint short and very transverse, joint 2 very short and weakly sclerotized, joint 3 longer than preceding one and slightly curved, joint 4 subconical, all joints, apart from the last one, fringed with long setae. Maxillae ( Fig. 11F View FIG ) with an elongate single membranous lacinia, covered with fine long setae, monolobed galea proximally sclerotized and distally clothed with very coarse medium sized thick spatulate setae (galeal brush; Fig. 11G View FIG )), maxillary palpi (including palpiger) 4-jointed, palpiger very small, joint 2 wide and relatively short, joint 3 about as wide as long, joint 4 long and subconical, distinctly longer than the preceding 2 together, apically bearing some short sensilla. Mandibles ( Fig. 11 View FIG A-D) relatively long, slightly asymmetrical, outer margin regularly convex, apiculus preceded by a short vertical tooth, apiculus relatively long and acutely pointed, exceeding the mesal brush by one third of the length, mesal brush narrow and well-developed, molar lobe very strong. Antennae 10-segmented ( Fig. 13F View FIG ), scape long (about half the total length of antenna), distally slightly clavate/ securiform, distally bearing some setae, funicle short with pedicellus plump and rounded, the remaining articles very short, distinctly wider than long, antennal club made of 3 articles, the first one expanded basally, oriented almost longitudinally following the longitudinal axis of the last article of funicle, articles of club hairy, relatively small.
Ventral areas of prothorax, apart from the sides, setigerously punctured, setae long and recumbent. Hypomeron smooth, very folded in. Procoxae transversely oriented, apices nearly touching each other; fore trochanters relatively wide, with fore tips bearing a tuft of long setae; profemora slender, fore edge distinctly concave, surface smooth with few recumbent setae; protibiae sexually dimorphic ( Fig. 13A, B View FIG ), apical spur relatively long, sharp, distally curved downward, protarsi with 1st article slightly longer than the following articles together, articles 2 and 3 slightly dilated, article 5 slightly longer than the 4th article, bearing 2 short curved claws, each tarsomere, with the exception of the last one, ventrally bearing a tuft of coarse fine setae. Mesosternum narrow, short and plump, forming a sharp and fine carina protruding between mesocoxae and joining metasternum, mesocoxae large, almost adjacent to each other, longitudinally oriented, trochanters narrow, with hind tip acute, mesofemora slender, surface smooth, with hind edge emarginated at distal 3rd, emargination preceded by a small distinct tooth; mesotibiae ( Fig. 13C, D View FIG ) relatively short, sexually dimorphic, inner angle of apex with one straight apical spurs in both sexes, mesotarsi inserted near the inner angle of apical edge, slightly longer than apical edge of tibia, with first 3 articles subequal, 4th shorter, 5th almost as long as the preceding 2, bearing 2 small curved claws; each tarsomere, with the exception of the last one, ventrally bearing a tuft of coarse setae; trochanters of metafemora narrow, with hind tip acute, metafemora plumper than mesofemora, surface hairy, hind edge distally with a small emargination, metatibiae ( Fig. 13E View FIG ) triangular, very wide, flat, ending with 2 sharp fine spurs paired at the inner angle of the tibia, metatarsi almost as long as the apical edge of tibia, first article almost as long as the following 3 together, 5th almost as long as the first one, claws small and feebly curved; each tarsomere, with the exception of the last one, ventrally bearing a tuft of coarse setae. Outer face of meso- and metatibiae with longitudinal striae along inner margin and a variable sculpturing and setation along outer margin.
Wings ( Fig. 12A View FIG ) (L wing/L elytron ratio = 2.1): with reduced and poorly sclerotized venation, MP 1+2 -RP loop absent, RP2 relatively long (although weakly sclerotized), apical field with a small vertical secondary sclerification near the radial cell.
Sexual dimorphism: females have the acute process of apex of head more protruding forwards and bent upwards ( Figs 10B View FIG ; 14 View FIG ), grooves of vertical part of clypeus deeper and setose process of vertical part of clypeus larger and more setose than in males, female protibiae ( Fig. 13B View FIG ) sharpened and S-shaped, ending with 2 small short teeth, apical spur of protibiae plumper with tip more dramatically bent downwards, mesotibiae more narrowed apically ( Fig. 13C View FIG ) ending with a short process bent outwards marked by a tuft of short setae, whereas males have the protibiae normally shaped, with a broad distal part and ending with a single small outer tooth ( Fig. 13A View FIG ), apical spur of protibiae slender and more gently bent downwards, and mesotibiae almost straight, without any tuft of setae apically ( Fig. 11D View FIG ). While in the rolled up posture the female conceals the protibia, which in turn is normally visible in the male ( Fig. 12B View FIG ).
Male genitalia: genital segment fairly sclerotized. Aedeagus dorsally flattened with basal piece very slightly twisted, longer than parameres; internal sac relatively small, usually extroflected forwards; temones present; parameres dorsally flattened.
Female genitalia: no bursal sclerites and spermatheca weakly sclerotized; genital palpi weakly sclerotized, relatively small and short.
REMARKS
Both Fairmaire (1900) and Paulian (1979) stressed the unusual morphology of the habitus of Philharmostes perrieri , but, having only a single specimen at hand, they did not go further. Dissection of the holotype of P. perrieri and the collection of a long series of a new species in January 2006 allowed me to discover the unique antennal and head morphology as well as the unusual sexual dimorphism and therefore to find many autoapomorphies warranting the establishment of a new genus. The nearest affinities of Pseudosynarmostes n. gen. are unknown and the set of unique characters distinguishing this genus is truly amazing. No other Ceratocanthinae possess such a modified vertical part of clypeus with a groove so deeply excavated and the “setose process”. Th e secondary sexual dimorphism is particularly interesting and unique within the family ( Ballerio 2006). Th e female protibiae have a shape not found in any other known genus, being sharpened and S-shaped, this perhaps could be related to digging capabilities for egg laying. It is interesting to notice another unusual feature related to the shape of female protibiae: once rolled up the female of Pseudosynarmostes n. gen. does not show the outer face of protibiae ( Fig. 12B View FIG ), which in turn are regularly visible in the male. Possibly the morphology of aedeagus, head and mouthparts could suggest some similarities with Synarmostes and the continental African genera Melanophilharmostes Paulian, 1968 and Pseudopterorthochaetes Paulian, 1977 but the phylogenetic position of this new genus will be discussed in another paper. The metathoracic wings of Pseudosynarmostes n. gen. are relatively long, although they show a weak and reduced wing venation, so it is not possible to state whether the species in this genus are able to fly or not. It must also be observed that the humeral area is rounded and lacks a humeral callus, a typical feature related to flightlessness ( Scholtz 2000).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.