Derelomus strelitziae Haran, 2025

Derelomus strelitziae Haran sp. nov.

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Fig. 12 View Fig

Diagnosis

Derelomus strelitziae sp. nov. can be distinguished from other species in the genus by its scutellum concealed by a dense cover of whitish setae. The body is flat in lateral view and the integuments on mature specimens are dark brown with a few pale brown patterns on the elytra. GenBank accession numbers for the corresponding DNA barcodes: ON553428 View Materials –29.

Etymology

The specific epithet refers to the genus name of the host plant of this Derelomus : Strelitzia nicolai .

Material examined

Holotype

REPUBLIC OF SOUTH AFRICA • ♂; “Republic of South Africa; KZN Pr. [ KwaZulu-Natal Province], Margate ; 6.x.2018; J. Haran coll.” “ -30.857 30.376 [30°51′26″ S 30°22′34″ E]; Strelitzia nicolai flowers; JHAR01561_0101 ; Cirad” “Holotype; Derelomus ; strelitziae ; Haran, 2025”; SANC.

GoogleMaps

Paratypes

REPUBLIC OF SOUTH AFRICA – KwaZulu-Natal Province • 2 ♂♂, 3 specs (preserved in ethanol); same collection data as for holotype; CBGP GoogleMaps • 1 ♂; same collection data as for holotype; MNHN GoogleMaps • 5 ♀♀; Bluff Nature Reserve ; 29°56′13″ S, 30°59′40″ E; Aug. 2008; Ş. Procheş coll.; on flowers of Strelitzia nicolai ; JHAR07394 ; CBGP GoogleMaps • 1 ♂, 2 ♀♀, 17 specs (preserved in ethanol); Durban, uMhlanga ; 29°43′09″ S, 31°05′27″ E; 7 Oct. 2010; J. Haran coll.; on flowers of Strelitzia nicolai ; JHAR01572 ; CBGP GoogleMaps • 2 ♂♂, 1 ♀; Queen Elizabeth Park , lake area; 29°34′19″ S, 30°19′27″ E; Jun. 2008; Ş. Procheş coll.; on flowers of Strelitzia nicolai ; JHAR07393 ; CBGP GoogleMaps • 1 ♂, 1 ♀; Enseleni; 28°41′21″ S, 32°00′00″ E; Oct. 2009; Ş. Procheş coll.; on flowers of Strelitzia nicolai ; JHAR07396 ; CBGP GoogleMaps • 1 ♂; same collection data as for preceding; TMSA GoogleMaps • 1 ♂, 1 ♀; same collection data as for preceding; NHMUK GoogleMaps • 2 ♂♂, 1 ♀, 8 specs (preserved in ethanol); Port Edward; 31°02′39″ S, 30°13′34″ E; 12 Jul. 2019; J. Haran coll.; on flowers of Strelitzia nicolai ; JHAR02369 ; CBGP GoogleMaps • 1 ♂; San Lameer, Mondazur Hotel ; 30°56′42″ S, 30°17′49″ E; Jul. 2012; Ş. Procheş coll.; on cultivated flowers of Strelitzia nicolai , but within natural range, naturally occurring less than 1 km away; JHAR07402 ; CBGP GoogleMaps • 1 ♂, 1 ♀; Sordwana Bay, 5 km NW of town; 27°28′42″ S, 32°38′42″ E; Oct. 2009; Ş. Procheş coll.; on flowers of Strelitzia nicolai ; JHAR07397 ; CBGP GoogleMaps • 1 ♂; UKZN Westville, School of Business ; 29°48′57″ S, 30°56′46″ E; Sep. 2009; Ş. Procheş coll.; on wall; JHAR07395 ; CBGP GoogleMaps • 1 ♀; UKZN Westville, Biomedical Center ; 29°49′24″ S, 30°56′52″ E; Nov. 2011; Ş. Procheş coll.; on flowers of Strelitzia nicolai ; JHAR07401 ; CBGP GoogleMaps • 1 ♀; Umtentueni ; Jul. 1953; E.L. Sleeper leg.; SANC • 2 ♂♂; Umbogintwini; 30°01′08″ S, 30°54′14″ E; Nov.– Jan. 1925; Hardenberg coll.; NHMUK. GoogleMaps – Western Cape Province • 1 ♀; Plettenberg Bay; 34°04′01″ S, 23°22′23″ E; Dec. 2009; Ş. Procheş coll.; on flowers of Strelitzia nicolai ; JHAR07398 ; CBGP. GoogleMaps – Eastern Cape Province • 1 ♂; Mbotyi village ; 31°27′55″ S, 29°43′55″ E; Dec. 2009; Ş. Procheş coll.; on flowers of Strelitzia nicolai ; JHAR07400 ; CBGP GoogleMaps • 1 ♂; same collection data as for preceding; MCZR GoogleMaps • 1 ♂; same collection data as for preceding; RB GoogleMaps • 1 ♀; Van Stadens Nature Reserve ; 33°54′40″ S, 25°13′09″ E; Dec. 2009; Ş. Procheş coll.; on cultivated flowers of Strelitzia nicolai , outside natural range; JHAR07399 ; CBGP GoogleMaps • 1 ♂; Summerstrand, Port Elizabeth ; 33°59′24.0″ S, 25°39′36.0″ E; Ş. Procheş coll.; on Strelitzia nicolai ; ANIC. GoogleMaps

Description ( ♂)

MEASUREMENTS. Body length 3.0–5.0 mm.

COLOR. Body integument dark brown, often reddish brown on teneral adults; tibiae, tarsi and scape reddish brown; elytra with pale brown patterns generally forming circles laterally on basal half and apical half; dorsum with minute whitish setae, glabrous in appearance.

HEAD. Rostrum slightly longer than pronotum in lateral view, moderately and regularly downcurved; in dorsal view 3.6× as long as wide, integument densely punctate, forming 5 longitudinal carinae from eyes to antennal insertion, covered with short recumbent and non-contiguous whitish setae oriented transversally; antennae inserted near apical 1/5 of length; head capsule coarsely punctate in dorsal view; eyes convex, exceeding lateral curve of head capsule in dorsal view; antennal funicle with segments 1–2 subequal in length, 1 wider than 2, 3–7 transverse.

PRONOTUM. Wider than long (W: L ratio: 1.23), widest near middle of length, slightly narrower there than elytra at humeral angles; sides straight, subparallel or slightly convex, abruptly converging in apical ¼, apical constriction as wide as width of scape at apex; integument densely and irregularly punctate, space between punctures smooth, dull; setae more visible laterally, as long as width of punctures.

ELYTRA. Sides subparallel or slightly convex, widest near 3/5 of length (W: L ratio: 0.56); humeri raised; apex rounded, not contiguous; striae with punctures as wide as or slightly narrower than interstriae; interstriae flat or slightly convex, 9 raised into carina; scutellar shield rounded, concealed by whitish setae.

ABDOMEN. Underside covered with minute recumbent whitish setae, not contiguous. Stridulatory plate with lines of 10 granules ¾× as long as median line ( Fig. 12E View Fig ).

LEGS. Profemora moderately thickened near middle of length; protibiae with external margin straight, meso- and metatibiae slightly curved outward in apical half, internal margin of protibiae bisinuate, carinate, bearing a comb of elongated golden setae as long as or longer than largest width of protibiae, extending from basal 1/5 to apex ( Fig. 12F View Fig ); meso and metatibiae lacking comb of elongated setae; claws simple.

TERMINALIA. Body of penis elongate (W: L ratio: 0.20), 2 × as long as apodemes; sides subparallel in dorsal view, widest near basal ⅓ of length, converging regularly apicad, apex acuminate; in lateral view curvature stronger in basal ½ of length, width narrowing apicad in apical ¼ ( Fig. 12D View Fig ).

Sexual dimorphism

Females can be distinguished from males by the rostrum which is strongly downcurved in lateral view ( Fig. 12C View Fig ), almost forming a quarter circle (only moderately downcurved in males), and narrow in dorsal view, with only superficial punctures and carinae (rostrum slightly wider with strong punctures and carinae in males). The antennae are inserted at the apical ⅓ of the rostrum (apical 1/ 5 in males).

Life history

This species develops on Strelitzia nicolai ( Strelitziaceae ), the larvae mine the floral peduncle. Adults stand hidden at the base and between the white petaloid sepals during the day. There is no indication that this species can develop from other species of the genus ( SP obs.). Strelitzia nicolai flowers show a structure and a production of nectar typical of ornithophily and sunbirds ( Passeriformes , Nectariniidae ) were identified as the main flower visitors and pollinators of this species ( Frost & Frost 1981). Given the pollination activity in Derelomus and the general trend of phylogenetic conservatism of this behaviour at genus level ( Haran et al. 2023a), the implication of this species as a co-pollinator would deserve investigations. Adults were collected from June to December.

Distribution

Derelomus strelitziae sp. nov. follows the distribution range of its host along the southern coast of the Republic of South Africa ( Eastern Cape, KwaZulu-Natal & Western Cape provinces). Because the host plant of this species is naturally widespread, abundant, and commonly cultivated – and flowers throughout the year – it provided an ideal opportunity to assess the species’ occupancy. During a dedicated field trip between May and August 2010, we surveyed as many inflorescences as possible at each location where the host plant, Strelitzia nicolai , was present across the genus’ distribution range ( Fig. 12G View Fig ). Most S. nicolai specimens sampled were from natural populations, except in Plettenberg Bay and Barberton near Mbombela, where cultivated plants were included. The target species was found in all but one locality, with a frequency of occurrence ranging from 2% to 33% of flowers sampled. Its presence in areas where S. nicolai is not native indicates that D. strelitziae has expanded its range alongside its host. Flowers of Strelitzia caudata R.A. Dyer and S. alba (L.f.) Skeels could not be sampled during this study.

Remarks

This species is quite polymorphic, in some small males the protibial comb of setae is reduced. Phylogenetic analyses show that D. strelitziae sp. nov. together with D. strangulatus sp. nov. is one of the two most early diverging species in Derelomus ( Fig. 33 View Fig ).