Asytesta Pascoe 1865

Setliff, Gregory P., 2012, 3462, Zootaxa 3462, pp. 1-125 : 32-34

Asytesta Pascoe 1865

Asytesta Pascoe, 1865: 426 . Type species: Asytesta humeralis Pascoe, 1865: 426 , subsequent designation in Setliff 2007: 10. Zygara Pascoe, 1885: 288 new synonymy. Type species: Asytesta doriae Kirsch, 1879: 19 , original designation.

Generic diagnosis. Asytesta has a well developed semicircular to subcordate carina on the vertex of the head ( Figures 102–106) that is also present in species of Cyamomistus , Nothotragopus , and Panopides in the crowned weevil group. This “crown” will distinguish Asytesta from all other weevil genera except the three aforementioned genera. It differs from these genera in the abruptly expanded flange located on the ventral margin of the protibia ( Figure 6), compressed tibiae, minute (sometimes absent) scutellum ( Figure 4), short metasternum, middle and hind coxae separated by distance less than one-half the length of a mesocoxa, and the intercoxal process on ventrite 1 is broader than long ( Figure 5). Additionally, the male rostrum in all Asytesta species lack a median, horn-like granule at the base ( Figure 3), which is found in all other crowned weevil genera for which the male is known ( Figures 9, 10, 13, 15, 17, male of Cyamomistus is not known).

Redescription. Body sub-globular, slightly broader than long to more than 2 X longer than broad. Length 3.4–10.5 mm, width 1.6–5.0 mm. Pronotum and elytra subequal in width. Integument dark reddish-brown to black, antennae, tarsi, and mouthparts reddish-brown. Dorsum sparsely to densely squamose, glabrous in A. doriae species group. Head, pleura, venter, legs, and tarsi variously squamose in all species. Ventral portion of head, dorsal and ventral apex of rostrum, and antennae glabrate to glabrous. Vestiture composed of appressed, elliptical background scales, interspersed with longer, suberect scales originating from punctures on dorsum and sparsely distributed on legs; suberect scales usually capitate, often lighter in color than background scales. Pronotum and elytra of most species variously marked with pale vittae or maculae.

Head. Convex, visible in dorsal view (except A. frontalis new species), with thin, glabrous, subcordate to semicircular, crown-like carina on vertex above eyes; crown with posterior margin interrupted by flattened, glabrous V-shaped area where head articulates on pronotum ( Figures 102–104, 106). Eyes situated sublaterally, finely faceted, slightly convex, as long as wide or slightly longer, subcordate to oval, dorsal and anterior margins rounded, posterior margin nearly straight. Interocular distance variable, narrower than basal width of rostrum to broader (compare Figures 105 and 106). Rostrum weakly and evenly arcuate, shorter than or equal to pronotal length, parallel sided to near apex, moderately widened and depressed at apex, with small, medial interocular pit at base often obscured by squamae. Dorsal face of male rostrum rugose from base to antennal insertions, smooth in female rostrum. Antennae inserted slightly beyond middle in both sexes; scrobe mostly concealed beneath sides of rostrum; scape not reaching eye, funicular articles 1 and 2 each longer than any remaining articles, article 7 as broad as long, larger and more densely setose than previous articles; club oval to elongate-elliptical, longer than or equal to length of funicular articles 1+2 ( Figure 7). Mandible simple, margin entire, without teeth, apex evenly convex, spoon-shaped. Ventral portion of head with very fine, parallel strigae; sparse at midline, more closely approximate and densely distributed on ventrolateral portion of head.

Thorax. Pronotum 1.0–1.5 X broader than long, usually broadest at base occasionally at middle, abruptly constricted towards head, sides rounded behind cervical constriction to more or less parallel sided ( Figure 4), usually coarsely punctate, with small, shiny, rasp-like granules at posterior margin of punctures (except A. doriae group), each granule bearing long, capitate, anteriorly directed, decumbent scale. Postocular lobes well developed ( Figure 3) with fine vibrissae covering posteroventral portion of eye when head in repose ( Figure 104). Posterior pronotal margin nearly truncate to weakly sinuate. Prosternal canal shallow to deep, with lateral margins nearly vertical, carinate; floor of canal and mesosternal receptacle usually glabrous, interior lateral margins squamose. Mesosternal receptacle slightly cavernous to cavernous, with lateral margins produced, posterior margin enclosed to slightly open or receptacle very shallow, nearly obliterated, lateral margins not or only weakly produced, posterior margin broadly open. Posterior margin of receptacle reaching middle of mesocoxae ( Figures 5, 104). External scutellum circular to oval, minute, absent in 4 species. Elytra and pronotum behind cervical constriction strongly convex in lateral view such that scutellum lies on significantly lower plane; humeri subcontiguous with posterolateral margin of pronotum, steeply declivous past midline or gradually sloping to apex. Elytral length variable, slightly broader than long to 1.5 X longer than broad. Anterior margin truncate to emarginate at middle. Humeri flattened and anteriorly produced in A. dorsalis and A. emarginata species groups. Laterally truncated at seventh intervals, most noticeable at humeri. Intervals typically granulate (smooth in A. doriae group); granules bearing a single decumbent scale. Granulate prominence on third intervals raised above all other intervals, intervals 4, 5, 6, and/or 7 also elevated in some species, always to lesser extent than intervals 3 (see Figures 69–80). Ten striae visible, tenth stria greatly reduced, usually restricted to basal 1/3 of elytra. Hind wing well developed or vestigial. Punctures on elytra circular, moderately deep to shallow, size variable, interspaces between punctures about half as long as puncture (interspace longer in A. doriae species group), each puncture bearing one, usually short, decumbent scale. Pleural sclerites with all margins entire; lateral portion of mesosternum square; mesepisternum triangular, small, lower margin not extending more than one half length of lateral portion of mesosternum; mesepimeron subparallel sided; metepisternum not concealed by epipleural margin of elytra, sclerolepidia not observed on anapleural suture. Metasternum very short, meso- and metacoxae closely approximate, intercoxal space narrower than width of mesocoxa, lateral portion punctate (often obscured by scales), posterior margin depressed anterior to metacoxa, resulting in produced ventrolateral ridge ( Figure 8).

Legs long, hind femur exceeding elytral apex by at least one-fourth its length, mesofemur usually reaching or exceeding elytral apex. Femora weakly sulcate beneath, with small subapical denticle on venter of meso- and metafemora, profemora unidentate ( Figures 42–44, 47–55, 58–59, 62–63), bidentate ( Figures 45–46, 56–57, 60–61), or secondarily edentate ( Figure 55). Tibia strongly compressed, sublinear, dorsal margin straight, convex, or emarginate at middle; ventral margin of protibia with thin blade-like flange, tapering to tibial apex ( Figure 6). Female often with broader, more gradually tapering flanges, male flanges more abrupt, sometimes reduced in length to broad tooth-like process (compare Figures 48 and 49); flange secondarily absent in 3 species. Ventral margin of protibia fringed with sparsely distributed, suberect, hair-like setae near apex; setae longer than background vestiture. Apex of protibia with well developed uncus and premucro, broadly separated with small flange situated in between, flange supporting long setae; subapex with oblique row of short stout bristles ascending from near uncus to perpendicular angle of apex, forming tooth-like supra-uncal projection ( Figure 6), sometimes greatly reduced or absent ( Figures 53–55). Hind tibia with apical setal brush of short stiff setae arranged almost vertically. Tarsomere 1 longer than tarsomeres 2+3; tarsomere 2 strongly depressed, short and trapezoidal, or elongate and clavate.

Abdomen. Ventrite 1 as long as or longer than remainder of abdomen (ventrites 2–5) and on distinctly lower plane, usually somewhat overlapping ventrite 2; ventrites 1 and 2 connate; intercoxal process on ventrite 1 broadly V-shaped, broader than total length of ventrite 1; ventrite 2 often transversely folded along middle, anterior half forming part of declivity of ventrite 1. Flat portion of ventrite 2 subequal in length to 3, ventrite 2 twice as long as ventrite 3 when not folded (as in A. emarginata group); ventrite 5 twice as broad as long.

Male terminalia. Tergite VII broader than long, anterior margin convex, posterior margin weakly emarginate at middle, with two rows of fewer than 8 plectral tubercles each reaching posterior margin; tubercles minute, usually visible only under high magnification ( Figure 81). Tergite VIII slightly longer than broad, posterior margin rounded. Sternite VIII obsolescent, with hemisternites completely membranous, apical margins setose near base ( Figure 82). Spiculum gastrale with apodeme shorter than aedeagal apodemes; apical arms well developed, asymmetrical ( Figure 85). Tegmen with parameres undeveloped ( Figures 86–87). Body of aedeagus (= median lobe of authors) one-third to one-fourth as long as apodemes, weakly curved; apex produced, setose; apodemes and body united. Endophallus with inverted Y-shaped apical sclerite, pair of small sclerites near base, and pair of elongate apodeme-like basal sclerites ( Figures 83–84).

Female terminalia. Tergite VII longer than broad, anterior and posterior margins broadly convex, with two rows of fewer than 8 plectral tubercles each; plectral rows not reaching posterior margin; tubercles minute, usually visible only under high magnification ( Figure 88). Vagina with walls weakly sclerotized. Bursa more or less indistinct from vagina. Tergite VIII longer than broad, apex rounded, margin smooth, with numerous short, stout setae arising submarginally on ventral and dorsal surfaces, middle weakly sclerotized from base to past midline ( Figure 89). Apical plate on sternite VIII broad, with two patches of 6–8 long setae at apex, apodeme broadly connected to apical plate, widened at apex ( Figure 90). Hemisternites elongate, narrow, subcylindrical, 3 X longer than styli; styli 3.5 X longer than broad, cylindrical, with short apical setae ( Figure 91). Spermatheca hook-shaped, apex of cornu variably acute to bluntly rounded ( Figure 92).

Distribution. Broadly distributed throughout the Papuan region ( Moluccas, New Guinea and surrounding archipelagos, and the Solomon Islands) ( Figures 1, 189–194).

Remarks. Following the generic description of Asytesta, Pascoe (1865: 426) discussed its relationship with the South American genus Rhyephenes Schönherr (Cryptorhynchinae) and the Indo-Australian genus Arachnobas Boisduval (Conoderinae) . The similarities between these genera are entirely superficial. It is not clear from his brief comments if Pascoe genuinely considered these genera closely related or if he included the remarks simply to illustrate the artificial resemblance between these them. Nevertheless, Gemminger & Harold (1871: 2563) arranged Asytesta after Rhyephenes in their catalog and Hustache (1936: 236) did the same in the Coleopterorum Catalogus.