Phlyctinus planithorax 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 : 16-19

Phlyctinus planithorax Haran sp. nov.

urn:lsid:zoobank.org:act:6D17741D-DBF6-4AF3-BD2B-DBBF5F0ADD8A

Figs 1D , 2D , 3D , 4E

Etymology

The species name refers to the absence of a median carina on the prothorax of this species.

Material examined

Holotype

REPUBLIC OF SOUTH AFRICA • ♂; Western Cape province, Gordons Bay; 34º10.823ʹ S, 18º49.843ʹ E; 14 Apr. 2019; at base of Hymenolepis crithmifolia (L.) Greuter ( Asteraceae ); CBGP code JHAR02264 ; SAMC.

Paratypes

REPUBLIC OF SOUTH AFRICA – Western Cape province • 2 ♂♂, 2 ♀♀; same collection data as for holotype; CBGP • 1 ♂, 1 ♀; same collection data as for holotype; SAMC • 1 ♂, 6 ♀♀; Gordons Bay ; 34º10.093ʹ S, 18º51.047ʹ E; 8 Nov. 2019; at base of Hymenolepis crithmifolia ; CBGP code JHAR03026; CBGP (ethanol coll.) • 7 ♂♂, 12 ♀♀; Gordons Bay, Sunbird ; 34º11.209ʹ S, 18º49.154ʹ E ;

8 Nov. 2019; at base of Carpobrotus edulis (L.) N.E.Br ( Aizoaceae ); CBGP code JHAR03027; CBGP (ethanol coll.).

Description

BODY LENGTH. 6.0– 6.8 mm.

COLOUR. Body integument black; vestiture of elytra consisting of elliptical scales, twice as long as wide, not concealing integument; scales pale or dark brown with scattered contrasting pearly green spots and an ill-defined transverse pale band on apical ⅔ of interstriae 1–3, mainly visible in females.

HEAD. Rostrum longer than wide (w/l ratio: 0.77) in both sexes, as wide as base at apex, sides slightly concave near middle of length in dorsal view; epifrons as wide as width of eye, at base narrower than distance between eyes, sides subparallel, 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 insertions 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 slightly narrower than diameter of eyes; mandibles trisetose, bare of scales. Forehead with a short longitudinal furrow between eyes; recumbent and suberect scales arranged centripetally towards a point below base of eyes, in dorsal view; eyes protruding, surface almost conical in dorsal view. Antennae slender, scape 0.75 × as long as funicle, slightly bisinuate, subclavate at apex, exceeding anterior margin of prothorax in repose; funicle with segments 1–2 elongate, 1 very slightly shorter (0.95 ×) 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. Wider than long (w/l ratio: 1.18), 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, upper face regularly convex, lacking carina or cuticular depression.

ELYTRA. Sides convex, widest before middle of length (w/l ratio: 0.75–0.80), integument micro-punctate and weakly reticulate, shiny, interstriae raised, 2–3× as wide as width of striae in basal half; small declivital callosities present on apical ¼ of interstriae 3, 5 and 7; each interstria with 1–2 series of semierect elongate brownish scales, condensed on callosities.

ABDOMEN. Underside with pearly green scales, scattered, not overlapping; ventrite 1 shorter than 2 +3+4, slightly convex in middle (♀) or concave with erect setae as long as claws (♂), ventrite 5 as long as 3+ 4, with sub-erect setae in middle and near apex (♀) or with a large cavity extending on apical ⁴⁄5, with long erect setae condensed on margin of cavity, forming two brushes at apical and basal margins, and a longitudinal line of erect setae in cavity, long in basal half and very short in apical half (♂) ( Fig. 3D ).

LEGS. Femora clavate, unarmed; tibiae straight, unarmed, slightly bisinuate on ventral side; claws simple, free, equal in length.

GENITALIA. Body of penis elongate, 0.65 × as long as apodemes, sides convex, widest in basal ¼ (w/l ratio: 0.44), in lateral view curvature weak ( Fig. 2D ); copulatory sclerite with left arm longer than body, not bearing setae at base; comb of right arm with setae converging, curved inward at apex; right area of body slightly wider than left area.

Sexual dimorphism

Males may be distinguished externally from females by the presence of a cavity and setae on ventrite 5. They usually lack a distinct transverse pale band on the elytra (visible on interstriae 1–3 in females).

Life history

All known specimens of P. planithorax sp. nov. have been collected at the base of Hymenolepis crithmifolia (Asteraceae) and Carpobrotus edulis (Aizoaceae) plants, which are probably its host plants ( Fig. 4 E–F). This species was not found on other plants present at the collection sites. Adults were collected in April and November.

Distribution

This species is only known from several sites of the western slope of the Kogelberg Mountain.

Remarks

Phlyctinus planithorax sp. nov. belongs to the P. littoralis sp. nov. species group and is similar to the other species included in it. Based on the series examined, it can be distinguished from them by the absence of a carina on its prothorax and by the erect scales on ventrites 1–4, which are more than twice as long as the recumbent scales (less than twice as long in P. littoralis sp. nov. and P. aloevorus sp. nov.). Phlyctinus planithorax sp. nov. is genetically closest to P. aloevorus sp. nov., the two species showing an interspecific uncorrected p-distance of 5.2%. The arrangement of erect setae on ventrite 5 of this species is similar to that of P. xerophilus sp. nov., but the erect setae on the median line are shorter and do not reach the apex of the cavity. Despite an intense search for Phlyctinus species in coastal habitats in the Western Cape province, this species was only found at the vicinity of its type locality.

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