Derelomus strangulatus Haran, 2025

Derelomus strangulatus Haran sp. nov.

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Fig. 13 View Fig

Diagnosis

Derelomus strangulatus sp. nov. can be distinguished based on the following combination of features: body very flat in lateral view, sides of pronotum strongly strangulate anteriorly, sexual dimorphism marked, protibiae of males with an internal comb of erect golden setae, females with a very narrow rostrum, 0.5× as wide as in males. GenBank accession number for the corresponding DNA barcode: ON553437 View Materials .

Etymology

The specific epithet refers to the distinctly strangulated apex of the pronotum of this species, which is unique in the genus.

Material examined

Holotype

REPUBLIC OF SOUTH AFRICA • ♂; “Republic of South Africa; WC Prov. [ Western Cape Province] Pringle Bay ; 28.xi.2019; J. Haran coll.” “ -34.347 18.826 [34°20′49″ S 18°49′34″ E]; Phoenix reclinata ; JHAR03077_0101 ; Cirad” “Holotype; Derelomus ; strangulatus ; Haran, 2025”; SAMC.

GoogleMaps

Paratypes

REPUBLIC OF SOUTH AFRICA – Western Cape Province • 7 ♂♂, 14 ♀♀; same collection data as for holotype; CBGP GoogleMaps • 1 ♂, 1 ♀; same collection data as for holotype; NHMUK GoogleMaps • 1 ♂, 1 ♀; same collection data as for holotype; MNHN GoogleMaps • 1 ♀; same collection data as for holotype; SAMC. GoogleMaps – KwaZulu-Natal Province • 1 ♀; St Lucia, Mission Rk ; 28°13′12″ S, 32°14′56″ E; 13 Dec. 1975; Phoenix reclinate ; E-Y: 971; Endrödy-Younga coll; TMSA. GoogleMaps

Description

Male

MEASUREMENTS. Body length 3.0– 4.2 mm.

COLOR. Body integument pale to dark brown; scutellar shield, median line and sides of pronotum, rostrum, funicle darker; elytra often darker in middle; dorsum with minute recumbent yellowish setae, not contiguous.

HEAD. Rostrum as long as pronotum in lateral view, moderately and regularly downcurved; in dorsal view 4× as long as wide, integument densely punctate, forming 5 longitudinal carinae from eyes to antennal insertion, median one interrupted before antennal insertion, prolonged into an elongated smooth and shiny area; covered with short recumbent and non-contiguous whitish setae oriented transversally; antennae inserted at apical ¼ of length; head capsule coarsely punctate in dorsal view, with marked furrow surrounding posterior margin of eyes; eyes convex, exceeding lateral curve of head capsule in dorsal view; antennal funicle with segment 1 slightly longer and wider than segment 2, 3–7 transverse, 5–7 and basal half of club usually darker.

PRONOTUM. Wider than long (W: L ratio: 1.20), widest in basal ½ of length, slightly narrower there than elytra at humeral angles; sides subparallel in basal ½, convex in apical ½, strongly strangulate near apical margin, constriction as wide as width of scape at apex; integument densely and irregularly punctate, space between punctures smooth, dull; setae only visible laterally, very small and recumbent, central area glabrous.

ELYTRA. Sides subparallel in basal ¾ of length (W: L ratio: 0.65); humeri raised; apex jointly rounded; striae with punctures 4× narrower than interstriae; interstriae convex, convexity slightly more marked on interstriae 5–6; scutellar shield rounded, glabrous, integument shiny.

ABDOMEN. Underside with minute recumbent whitish setae, not contiguous. Stridulatory plate with lines of 6–7 granules 2/5 × as long as median line.

LEGS. Profemora moderately thickened near middle of length; protibiae with external margin straight, meso- and metatibiae slightly curved outward near apex, internal margin straight, carinate, bearing a comb of elongated golden setae as long as largest width of protibiae, extending from basal ¼ to apex; meso and metatibiae lacking comb, downcurved in apical 1/5; claws simple.

TERMINALIA. Body of penis elongate (W: L ratio: 0.23), 2× as long as apodemes, widest near base; sides subparallel in dorsal view, slightly converging apicad in basal ⅔ of length, convex in apical ⅓, apex truncate; in lateral view curvature stronger in basal ½ of length, width narrowing apicad in apical ⅓ ( Fig. 13D View Fig ).

Sexual dimorphism

See section Diagnosis for the main distinguishing features. The rostrum of females is also longer and more downcurved in lateral view than in males. The antennae are inserted near the middle of the length in females (at apical ¼ in males).

Life history

Derelomus strangulatus sp. nov. was collected in several localities on the inflorescences of the wild date palm Phoenix reclinata ( Arecaceae ), which probably constitutes its host plant. Adults were collected in November and December.

Distribution

This species is endemic to the Republic of South Africa in our current knowledge. It was found near the coast in KwaZulu-Natal and Western Cape provinces. The population in the Western Cape is out of the natural range of P. reclinata and probably results from an introduction of this weevil with its host widely planted for ornamental purpose.

Remarks

Phylogenetic analyses show that D. strangulatus sp. nov. together with D. strelitziae sp. nov. is one of most early diverging species in Derelomus ( Fig. 33 View Fig ).