Phlyctinus littoralis Haran, 2020

Haran, Julien M., Hansen, Steffan, Benoit, Laure & Addison, Pia, 2020, Description of five new species in the genus Phlyctinus Schoenherr (Coleoptera, Curculionidae): a first step in deciphering the P. callosus complex, European Journal of Taxonomy 669 (669), pp. 1-29 : 19-21

Phlyctinus littoralis Haran sp. nov.

urn:lsid:zoobank.org:act:49467405-4829-4E45-A2A5-70130EDA95E8

Figs 1E , 2E , 3F

Etymology

Phlyctinus littoralis sp. nov. is named in reference to the coastal habitat in which it was found and to which it seems to be restricted.

Material examined

Holotype

REPUBLIC OF SOUTH AFRICA • ♂; Western Cape province, Kogel Bay; 34º14.617ʹ S, 18º51.174ʹ E; 12 May 2018; at base of Arctotis angustifolia L. ( Asteraceae ); CBGP code JHAR00973 ; SAMC .

Paratypes

REPUBLIC OF SOUTH AFRICA • 2 ♂♂, 2 ♀♀; same collection data as for holotype; 16 Sep. 2018; CBGP • 1 ♂, 1 ♀; same collection data as for preceding; SANC .

Description

BODY LENGTH. 5.2–6.4 mm.

COLOUR. Body integument dark red, head and prothorax darker, usually black; vestiture of elytra with elliptic elongate scales, twice as long as wide, not concealing integument, greyish, forming a homogeneous grey appearance, usually with an ill-defined paler band on apical ⅔ of interstriae 1–3.

HEAD. Rostrum longer than wide (w/l ratio: 0.63) in both sexes, at base as wide as at apex, sides slightly concave near middle of length; epifrons slightly narrower in middle of length than width of eye in dorsal view, at base narrower than distance between eyes, sides subparallel, slightly widening apicad, upper face with a longitudinal carina extending from basal transverse groove to nasal plate, visible through scales; nasal plate V-shaped, reaching level of antennal insertion basally, bare of scales, with only minute setae inserted in scattered punctures and 3 pairs of long setae apically near insertion of mandibles (2 short and 1 very long); antennal scrobes slightly curved in lateral view, directed to middle of eye, separated from it by a strip of scales half as narrow as diameter of eyes; mandibles trisetose, bare of scales. Forehead with a short longitudinal furrow between eyes, scales and setae arranged centripetally towards a point below base of eyes; eyes protruding, margin rounded, surface slightly conical in dorsal view. Antennae slender, scape 0.8× as long as funicle, slightly bisinuate, subclavate at apex, exceeding anterior margin of prothorax in repose; funicle with segments 1–2 elongate, 1 slightly shorter (0.85 ×) than 2, segments 3–6 longer than wide, conical, shortening apicad, segment 7 longer and slightly wider than 6; club spindle-shaped, segment 1 longer than 2, margins slightly sinuous.

PROTHORAX. Slightly wider than long (w/l ratio: 1.20), widest near middle of length, apical margin 0.6× as wide as basal margin, sides rounded, apical half slightly concave; integument densely punctate, spaces between punctures forming ill-defined, concentric smooth ridges and a small, smooth and shiny median carina visible in approximately 50% of individuals; upper face regularly convex, lacking depressions.

ELYTRA. Sides convex, widest near middle of length (w/l ratio: 0.76–0.83), integument finely punctate and reticulate, shiny, interstria raised, 3–4 × as wide as width of striae in basal half; large declivital callosities absent or very reduced in apical ¼ of interstriae 3, 5 and 7; each interstria with a series of semi-erect elongate whitish scales, slightly more condensed in spots on declivity.

ABDOMEN. Underside with scattered scales similar to those on elytra, not concealing integument; ventrite 1 as long as 2+ 3+4, slightly convex in middle (♀), or concave with erect setae as long as claws (♂), ventrite 5 longer than 3 +4, with recumbent elongate setae in middle and near apex and a weak longitudinal carina near apex (♀) or with a large cavity extending over apical ⅔, with long erect setae mainly condensed on middle of basal margin of cavity and a brush on either side of apical margin; bottom of cavity with a few short recumbent or semi-erect setae (♂).

LEGS. Femora clavate, unarmed, with a double vestiture of recumbent and semi-erect greyish scales; tibiae straight, unarmed, slightly bisinuate on ventral side; claws simple, free, equal in length.

GENITALIA. Body of penis elongate, 0.75 × as long as apodemes, sides almost straight, converging regularly towards apex, more abruptly near apex, widest at base (w/l ratio: 0.40), in lateral view curvature weak, slightly stronger near middle of length ( Fig. 2E ); copulatory sclerite with left arm longer than body, not bearing setae at base; comb of right arm with setae converging; right area of body slightly wider than left area.

Sexual dimorphism

Males may be distinguished externally from females by the slightly more slender elytra (w/l ratio: 0.76, 0.83 in ♀) and the cavity and setae on ventrite 5.

Life history

The type series of P. littoralis sp. nov. was collected from the base of Arctotis angustifolia (Asteraceae) plants growing on the gravel parts of Kogel Bay beach ( Fig. 4 G–H). Adults were collected between May and September but gravid females only in May.

Distribution

This species is only known from its type locality.

Remarks

Phlyctinus littoralis sp. nov., P. planithorax sp. nov. and P. aloevorus sp. nov. form a species group characterized by the presence of only very small or no tubercles on the elytral declivity and short setae on ventrite 1 of the males. Preliminary phylogenetic analysis of COI sequences indicated that they form a distinct genetic cluster ( Fig. 5 ). They have so far only been found in coastal habitats. Phlyctinus littoralis sp. nov. is most closely related to P. planithorax sp. nov., from which it can easily be distinguished by its homogeneous grey vestiture. The two species show an interspecific genetic p-distance on COI of 4.6%.

Figures

Fig. 1 (opposite page). Habitus of species of Phlyctinus Schoenherr, 1826 males (left) and females (right). A. P. callosus (Schoenherr, 1826). B. P. grootbosensis Haran sp. nov. C. P. xerophilus Haran sp. nov., holotype ♂. D. P. planithorax Haran sp. nov., holotype ♂. E. P. littoralis Haran sp. nov., holotype ♂. F. P. aloevorus Haran sp. nov., holotype ♂. Scale bars = 3 mm .

Fig. 2. Penis of Phlyctinus Schoenherr, 1826, in dorsal (left) and lateral (right) view, and copulatory sclerite (top right). A. P. callosus (Schoenherr, 1826). B. P. grootbosensis Haran sp. nov. C. P. xerophilus Haran sp. nov., holotype ♂. D. P. planithorax Haran sp. nov., holotype ♂. E. P. littoralis Haran sp. nov., holotype ♂. F. P. aloevorus Haran sp. nov., holotype ♂. Scale bars = 500 µm. Copulatory sclerite not to scale.

Fig. 3 (opposite page). A–B. Ventrites of males of Phlyctinus Schoenherr, 1826 (left: ventrites 1–5, right: ventrite 5). A. P. callosus (Schoenherr, 1826). B. P. grootbosensis Haran sp. nov. C–D. Ventrite 5. C. P. xerophilus Haran sp. nov., holotype ♂. D. P. planithorax Haran sp. nov. E–F. Vestiture of basal right side of elytra. E. P. callosus (Schoenherr, 1826) (left). F. P. littoralis Haran sp. nov. Scale bars = 0.5 mm.

Fig. 4 (opposite page). Habitus in natura, host plants and biotopes of Phlyctinus Schoenherr, 1826 species. A. P. callosus (Schoenherr, 1826). B. P. xerophilus Haran sp. nov. C–D. P. grootbosensis Haran sp. nov. and its host plant, Osteospermum moniliferum L. E–F. P. planithorax Haran sp. nov. and its host plant, Hymenolepis crithmifolia (L.) Greuter. G–H. Biotope and host plant (Arctotis angustifolia L.) of P. littoralis Haran sp. nov. I–J. P. aloevorus Haran sp. nov. on its host plant, Aloe arborescens Mill., with details of feeding damage on floral peduncle .

Fig. 5. PhyML tree of Phlyctinus Schoenherr, 1826 species inferred from mitochondrial Cytochrome oxidase I (COI, 658 base pairs). Bootstrap support values as obtained from 1000 replicates (*above 80, ** above 95). Specimens codes were shortened for representation: JHAR0 = J and _0101 = -1.