Rhynchitapion pallidum, Wanat, 2021

Wanat, Marek, 2021, New basal taxa of South African Apioninae (Coleoptera: Curculionoidea: Brentidae), Zootaxa 5035 (1), pp. 1-60 : 15-19

Rhynchitapion pallidum sp. n.

( Figs. 56–88 , 290 )

Type material. Holotype ♂: a) RSA (S) E Cape 255 m /- 33.9649S / 23.6627E / Tsitsikamma N.P. / Khoisan Village , Rugbos trail/(circuit), medium wet forest/ 22.11.2013, leg. M. Wanat ( SANC) . Paratypes (6 ♂ 8 ♀): Eastern Cape: a) S. Africa. / R . E.Turner. / Brit. Mus. /1923–510, b) Port St John,/ Pondoland. / Sept. 1923 (1 ♀, BMNH); a) S. Africa. / R . E.Turner. / Brit. Mus. /1932–521, b) E. Cape Prov. / Katberg / 4000ft. Oct.1932 (1 ♂ 1 ♀, BMNH); Xholorha Forest , yellow trail 0-1.1 km, - 32.5368S / 27.3647E, 940-1050 m, 17.11.2013, leg. R . Ruta (1 ♂, MWC); Tsitsikamma N.P.: Big Tree Forest trails, - 33.9656S / 23.8947E, 260 m, 21.11.2013, leg. MW (1 ♂, MWC) ; same data as holotype (2 ♀, MWC), 22- 23.11.2013, leg. R . Ruta (1 ♀, MWC). Western Cape: a) South Africa, CP/ Bloukrans Pass,/ Tsitsikamma , / 33.57S 23.38E / 06.xii.1988 / R . Oberprieler [-33.95/23.6333] (2 ♀, SANC); a) S. Afr ..: Cape Prov. / Lily Vlei Nat. Res. / 33.56 S — 23.02 E, b) 4. 1983/wet forest/leg. J. Koen [-33.9333 / 23.0333](1 ♀, TMSA); a) S.Afr., S. Cape /Hark- erville Forest / 34.04S- 23.10E, b) 14.12.75, E-Y: 1313/ Sift. at for. marsh/leg. Endrödy-Younga [-34.0667 / 23.1667, one specimen teneral, with deformed elytra] (2 ♂, TMSA); Tsitsikamma N.P.: Nature’s Valley , Grootkloof trail, km 0-1.5, - 33.9678S / 23.5604E, 10-30 m, 23.11.2013, beating, leg. R . Ruta (1 ♂, MWC) .

Diagnosis. Much less variable and usually smaller (<3.0 mm) than Rh. variiforme sp. n., differing from the latter species in orange-testaceous head with rostrum, antennae and legs, sparser and all golden-yellowish erect setae on entire body, longer and weaker curved rostrum, narrower head, not enlarged junction of elytral striae 3+8, penis narrowly rounded apically, female having sinuous spiculum ventrale, common oviduct at base with peculiar 3-lobate expansion. It can be distinguished from the uniformly brown Rh. usambarense sp. n. by the presence of darker fasciae on elytra, more numerous long setae on the whole body, longer and narrower rostrum and elytra, and narrower penis. Moreover, Rh. pallidum sp. n. is distinct from both congeners in having by far the thinnest tarsi (basal protarsomere well over 3 × as long as wide) and having frena as the only sclerites in endophallus.

See also the key to Rhynchitapion species below.

Description. Body 1.90–2.65 mm long, together with appendices light testaceous; elytra lighter than pronotum, pale testaceous or yellowish, with more or less distinctly darkened suture (but not entire sutural intervals), basal twothirds of intervals 9 and 10, and shorter median portions of intervals 7 and 8, additionally each with a variably sized darker fleck in middle of intervals 3–5; intervals 2 and 6 always remaining entire not darkened ( Fig. 57 ). Antennae entirely light testaceous, concolorous with rostrum and legs. Erect hair-like setae fine, all golden-yellow, on elytra not longer than combined breadth of three intervals.

Morphological indices (n=11): rl/pl: ♂ 1.15–1.38 (M: 1.28), ♀ 1.37–1.68 (M: 1.54); rl/mxrw: ♂ 3.43–4.40 (M: 3.91), ♀ 4.10–5.15 (M: 4.59); scl/msrw: ♂ 1.33–1.74 (M: 1.50), ♀ 1.46–1.77 (M: 1.64); msrw/mtrw: ♂ 1.03– 1.10 (M: 1.06), ♀ 1.10–1.12 (M: 1.11); msrw/arw: ♂ 1.03–1.15 (M: 1.06), ♀ 0.95–1.03 (M: 1.00); msrw/minrw: 1.03–1.20; msrw/eyl: 0.73–0.87; brl/eyl: ♂ 1.55–2.22 (M: 1.85), ♀ 1.71–2.30 (M: 2.12); eyl/hl: 0.58–0.73; frw/ mtrw: ♂ 0.90–1.05 (M: 0.99), ♀ 1.00–1.15 (M: 1.07); hl/hw: 0.68–0.81; mpw/hw: 1.10–1.23; bpw/apw: 0.95– 1.07; pl/mpw: 1.10–1.24; mew/mpw: 1.72–1.95; el/pl: 2.77–3.14; el/mew: 1.74–2.00; mew/bew: 1.29–1.48; bew/mpw: 1.25–1.45; pft/msrw: 1.06–1.28; ptbl/pl: 1.13–1.31; ptbl/ptbmw: ♂ 6.86–7.25 (M: 6.99), ♀ 8.55–9.83 (M: 9.33).

Rostrum parallel-sided, without expansion at antennal insertion, weakly dilated at base ( Figs. 63, 64 ), in profile slightly regularly arched ( Figs. 58, 65 ); entire rostrum finely punctate, on metarostrum also with obsolescent fine dorsal median rib, often incomplete; on sides upper margin of scrobe extended towards rostrum base as fine darker carina ( Fig. 65 ); prorostrum ventrally with thin flat median keel not associated with regular sulci, punctures unordered, partly contiguous, with short, half-erect setae; septum of scrobes flat, vanishing well before head venter; the extreme base of rostrum ventrally with fine irregular furrows.

Antennae 0.8–0.9 × as long as elytra, entirely unicolorous and with protruding setae ( Fig. 66 ); antennal insertion sexually different ( Fig. 63, 64 ), ♂: 0.50–0.55, ♀: 0.44–0.49 from rostrum base; length/width ratio: scape 5.5–6.8, fun1 3.6–4.0, fun2 3.3–3.9, fun6 2.2–2.6, fun7 2.0–2.4, club 5.9–6.8; length of scape/fun1 1.6–1.9, fun1/ fun2 1.0–1.1, fun3–fun7 all similar, 0.6–0.7 × as long as fun1; club longer than combined length of four most distal funicular segments, with denser and weaker protruding setae.

Head narrower than in Rh. variiforme sp. n. ( Figs. 63, 64 ); eyes almost semi-globular; epifrons between eyes slightly concave, with five short longitudinal sulci not much wider than single ommatidium; genae with several fine protruding setae, often arranged in a sparse subocular fringe; temples with a single row of setiferous punctures along posterior margin of eyes, then with several flattened wrinkles ( Fig. 65 ); vertex in middle with small setiferous punctures, on sides in front with punctures bearing long erect setae, posteriorly with few wrinkles continued from temples; gular sector convex, impunctate, between eyes with several blurred transverse wrinkles extending upwards to temples.

Pronotum shaped as in Fig. 60 , widest in middle, shiny; punctuation differentiated, in front and middle of disc very fine, with few punctures smaller than ommatidium, bearing long erect setae, in basal half and on sides with punctures a few times larger and much denser, some lateral ones arranged in oblique rows, bearing setae 3–4 × shorter and semi-recumbent ( Fig. 61 ); basal edge of pronotal disc slightly raised; prosternum elevated on anterior margin and declining posterad, about 3 × shorter than hypomeron; prosternellum small, prominent as a conical tubercle; hypomeron with a complete raised rim of procoxae, bare, with irregular elongate punctures on sides.

Scutellar shield minute, flat, subquadrate.

Elytra regularly convex, with indistinct caudal part, broadest in middle or slightly behind ( Figs. 57, 58, 62 ); striae shallowly impressed, not sharply edged, with small and distant punctures having minute semi-recumbent setae shorter than double diameter of ommatidium, surrounded with visible internal elongate integumental chambers forming catenulate rows darker than pale integument of elytron; intervals gently convex, polished, impunctate, in middle several times broader than striae, in basal parts with sparse minute setae beside the long erect ones; interval 1 weakly raised along suture along middle third of its course; erect setae golden-yellowish, at most 3 × as long as breadth of intervals, gently bent posterad, more distant from each other than double interval’s breadth.

Wings as in Rh. variiforme .

Mesoventrite with a pair of small punctured fields, partly covered by prothorax; anapleural sutures well seen as dark lines; mesepimeral furrow narrow, with a single row of shortly setiferous punctures. Metaventrite smooth, very finely and sparsely punctate, on sides with long semi-recumbent setae; posterior rim of mesocoxae separated with distinct line. Abdomen elongate, 1.25–1.30 × as long as wide; ventrites 1–2 and 5 with minute and sparse setiferous punctures; ventrites 3–4 microreticulate; ventrite 5 with setiferous punctures denser on sides and close to apical margin.

Legs long and thin. Femora slender, 2.8–3.0 × as long as high, with shiny integument, around with semi-erect setae, scale-like microsculptured only near articulations. Protibia on inner side sharply edged in distal half (more distinctly in males), and along distal one-third with appressed setae, not forming a distinct stripe; apical comb of golden setae inconspicuous. Protarsus as in Fig. 68 , 4.2–4.8 × as long as wide; tarsomere 1 cylindrical at least in basal half, tarsomere 2 weakly widened apicad, both with a minute black median dot on apical margins; length/ width ratio of tarsomeres: 1st—3.2–4.5, 2nd—1.6–2.0, 3rd—0.9–1.1; onychium protruding beyond tarsomere 3 by 0.40–0.55 own length; claws with small triangular teeth ( Fig. 59 ).

Male. Protibia slightly bent inwards apically ( Fig. 69 ); meso- and metatibial mucro as in Fig. 67 . Abdominal ventrite 5 subtruncate apically, about 2.0 × as broad as long ( Fig. 74 ). Posterior margin of tergite VII with a very short fringe of microchaetae ( Fig. 73 ). Pygidium more rectangular in outline ( Fig. 70 ) and more globose than in Rh. variiforme , with apical declivity nearly vertical ( Fig. 71 ); internal tongue-like process isodiametric ( Fig. 72 ). Sternite VIII with lateral arms shorter than in Rh. variiforme and with fine sclerotized lines along basal and apical margins ( Fig. 81 ). Paired additional sclerites in the membrane between sternites VIII and IX circular. Spiculum gastrale symmetrical with straight arms ( Fig. 82 ). Tegmen with apodeme as long as basal piece arms ( Fig. 78 ); tegminal plate about twice as long as wide ( Fig. 77 ), widest subapically; suprafenestral sclerotizations asymmetrical, with straight basal margin, not fully marginal and surrounded apically with very short transparent membrane, bearing 5–6 long macrochaetae; transparent fenestral sector much smaller than in Rh. variiforme , with anterior extensions of prostegial lateral sclerotization reaching suprafenestral sclerites, additionally each parameral lobe laterally with a short longitudinal sclerotized carina; median transparent stripe of fenestral sector with microchaetae; postfenestral plate short, its margin closer to parameral lobes blurred; prostegium with well delimited one-third wide lateral sclerotized stripes and median transparent one. Penis with apodemes slightly shorter than pedon; pedon about 3.2–3.3 × as long as wide, slightly sinuate apically in profile ( Figs. 75, 76 ), in dorsal view regularly narrowing since about two-thirds length from base and narrowly rounded apically, apex poorly canaliculate and the lines not evidently radiate; endophallus with no sclerites but a pair of clavate frena situated at the pedon base in repose; inflated endophallus with a subtriangular apex having two pairs of v-like positioned dorsal conical lobes laying above each other, additional pair of finger-like latero-ventral lobes based at about the level of gonopore, bent apically; additional low median lobe present between the ventral lobes; ejaculatory duct entering in a deep dorsal depression before the inflated and lobate apex of endophallus ( Figs. 79, 80 ); gonopore on a small, bipartite, densely microspinose internal lobe ended with a minute hook.

Female. Abdominal ventrite 5 broadly rounded apically, about 1.7 × as long as wide, at inner side in a transmission light with sharply delimited bladal sclerotization, not margined by any rim or carina, just by a border line ( Fig. 88 ). The fold of genital sheath encompassing ovipositor with dense transverse rows of strongly transverse microplates. Tergite VII narrowly rounded, with marginal rim ( Figs. 83, 84 ). Tergite VIII divided into a pair of thin, largely reduced hemitergites forming a semi-circle in repose ( Figs. 84, 86 ). Spiculum ventrale strongly sinuate, with obsolescent basal plate ( Figs. 84, 86 ). Gonocoxites as in Fig. 85 ; styli long and narrow, more than 3 × as long as wide. Bursa large, simply membranous, subrectangular in profile when inflated. Common oviduct with a peculiar membranous accessory gland bearing three finger-like smaller lobes ( Fig. 87 ). Spermatheca narrow, with elevated bulbus receiving small gland and thin cornu abruptly bent subapically ( Fig. 56 ).

Biology unknown. Rainforest species.

Distribution. R.S.A. (Eastern Cape, Western Cape), from Port St Johns in the north to Harkerville in the south ( Fig. 290 ).

Etymology. The name consisting of Latin adjective pallidus —pale, with ending – um appropriate for neuter, and referring to generally light colour of the species, specifically of the elytra.

Figures

FIGURES 44–56. Rhynchitapion variiforme sp. n. (44–55). Male, inflated endophallus in dorsal (44) and lateral (45) views. Female, Karkloof: tergite VIII (46); sternal plate of spiculum ventrale (47); tergite VII (48). Female, Wilderness, gonocoxites, tergite VIII and spiculum ventrale (49). Male and female in copulation, Katberg: whole abdomina, male right (50); terminalia, male left (51); female terminalia with male endophallus in bursa, dorsal (52) and lateral (53) views; male terminalia, showing position of endophallic sclerites (54). Spermathecae: Rh. variiforme sp. n. (55); Rh. pallidum sp. n. (56).

FIGURES 57–74. Rhynchitapion pallidum sp. n. Male, Tsitsikamma, dorsal habitus (57). Female, Lily Vlei: lateral habitus (58); tarsal claws (59); prothorax in dorsal (60) and lateral (61) views; elytra in postero-lateral view (62). Rostrum and head in dorsal view, female (63), male (64).Female: rostrum and head in lateral view (65); antenna (66). Male metatibial mucro (67). Female protarsus (68). Male: protibia with mucro (69); pygidium in dorsal (70), lateral (71) and ventral (72) views; tergite 7 (73); abdominal ventrites (74).

FIGURES 75–91. Rhynchitapion pallidum sp. n. (75–88). Male: penis in dorsal (75) and lateral (76) views; tegminal plate, dorsal view (77); tegmen, lateral view (78); aedeagus with inflated endophallus in lateral (79) and dorsal (80) views; sternite VIII (81); sternite IX and additional sclerites (82). Female: tergite VII, dorsal view (83); tergites VII and VIII in posterior view and spiculum ventrale (84); gonocoxites (85); tergite VIII in dorsal view and sternal plate of spiculum ventrale (86); inflated bursa with accessory lobes (87); abdominal ventrites in transmission light (88). Rh. usambarense sp. n., holotype, male (89–91): sternite IX (89); tegminal plate in dorsal (90) and lateral (91) views.

FIGURES 289–296. Distribution in Africa: Rhynchitapion variiforme sp. n. (289); Rh. pallidum sp. n. (290); Rh. usambarense sp. n. (291); Apodytapion stepniewskii sp. n. (292); Turnerapion pondoense sp. n. (293); Lepanomus crinalis crinalis Balf.-Br. (294, circles); L. crinalis zuluensis ssp. n. (294, triangles); Lepanomidius ruthmuellerae sp. n., males (295, circles); Lepano- midius sp. cf. ruthmuellerae, female (295, triangle); Lepanomidius magdaloides sp. n. (296).

FIGURES 1–15. Rhynchitapion variiforme sp. n. Examples of colour forms and variation in size (all in the same scale): female, Komga (1); female, Karkloof (2); female, Tsitsikamma (3); male, Mariepskop (4); female, Wakefield (5); male, Karkloof (6). Holotype, male, dorsal habitus (7); male, Wakefield, habitus (8) and pronotum (9) in lateral views. Examples of pronotum, dorsal view: holotype, male (10); female, Karkloof (11). Rostrum in lateral view, male (12), female (13). Rostrum in dorsal view, male (14), female (15).