Alloraphes cantusfurca, Egan & Loewen & Mckellar, 2025

Alloraphes cantusfurca sp. nov.

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( Figs. 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 )

Type Material: Holotype specimen RSKM _ P3301.54 a ♂ , Paratype specimen RSKM _ P3301.54 b ♂, Dominican amber, Yanigua Formation, Miocene 20–15 Ma ( Iturralde-Vinent & Macphee 2019) (Commercial specimen, Dominican Republic, El Valle) .

Diagnosis. The main feature which separates A. cantusfurca from other taxa is its structure of aedeagus; long slender median lobe, parameres slender with rounded apices possessing singular long setae. Other characteristics informative in combination include; frons and vertex confluent without impression, pronotum with arcuate antebasal transverse groove without median pit, elytra modified with impressed apical region and pointed apices, aedeagus in ventral view ( Fig. 2G View FIGURE 2 ) with slight asymmetry in apex of median lobe; apical projections not visible.

Description— BL = 0.83 mm, BW = 0.34 mm. Body ( Fig. 2A, C View FIGURE 2 ) is ovate, convex and pubescent, weakly constricted between head and pronotum, and distinctly constricted between pronotum and elytra.

Head ( Fig. 2C View FIGURE 2 ) prognathous, sub-triangular, slightly wider than long (HL = 0.13 mm, HW = 0.16). Vertex weakly convex, shallow concave depression between eyes ( Fig. 3H View FIGURE 3 ). Frons flat, gradually declining anteriorly, posteriorly confluent with vertex. Frons constricted between antennal insertions, projecting anteriorly, subtriangular in shape. Strongly convex and moderately coarsely faceted compound eyes cover temporal region, forming widest portion of head. Occipital constriction slightly narrower than vertex.Antennal insertion visible dorsally ( Figs. 2A,C View FIGURE 2 ; 3D,E View FIGURE 3 ), separated by>1.5 times diameter of antennal socket.

Labrum ( Fig. 3E View FIGURE 3 ), anterior margin straight, lateral margins rounded.

Mandibles ( Fig. 3I View FIGURE 3 ) slightly asymmetrical compared to one another. Median tooth difficult to discern in CT-scan rendering.

Maxillary palps strongly elongate; palpomere I small, approximately as long as it is broad; palpomere II strongly elongate, pedunculate and gradually thickening distally; palpomere III strongly elongate and slightly longer than II, nearly cylindrical in distal half with widest point near distal end; palpomere IV approximately half as long as III, subconical with pointed apex delimited by a sulcus.

Labial palps ( Fig. 3F View FIGURE 3 ) narrowly separated at base; composed of 3 palpomeres: palpomere I and III similar length and width; palpomere II is longer than I and III combined, thin and pointed.

Antennae long relative to body length (0.26 times total body length; AnL = 0.30 mm), clavate, covered in setae; composed of 9 flagellomeres which gradually increase in size, scape and pedicle each larger than flagellomere I. Antennomeres IX–XI form indistinctly delimited club.

Pronotum ( Fig. 2C View FIGURE 2 ) 1.21 times as long as wide, broadest at middle (PL = 0.23 mm, PW = 0.19). In dorsal view, pronotum convex, bell-shaped; anterior and lateral margins rounded. Pronotum anterior angles not distinctive, poorly developed; with short, dense, and sub-erect setae present on sides of pronotum; antebasal groove distinct, lacking median pit.

Prosternum ( Fig. 2D View FIGURE 2 ) small, rectangular, wider than long. Intercoxal process acute.

Mesonotum with scutellum visible, sub-triangular in shape with rounded apex.

Mesoventral intercoxal process acute and projecting ventrally, connecting anteriorly with anterior ridge. Metaventrite laterally ridged; posterior transversely ridged. Metacoxal process acute and triangular, unclear if metacoxal process is notched in middle, due to artefacts in 3D renderings and limited visibility in amber.

Elytra ( Fig. 2A,C View FIGURE 2 ) sub-ovoid in shape (EL = 0.47 mm, EW = 0.34 mm, EI = 1.40 mm) modified with pointed apices which are impressed. Surface structure and sculpture of elytra difficult to discern in amber microscopy and CT model. Distinct sub-humeral lines present, with lengths approximately one-third of elytral length. Elytra densely covered with long, sub-erect setae. Pygidium not exposed.

Legs ( Fig. 3E View FIGURE 3 ) moderately long and slender. Procoxae and mesocoxae sub-globular and weakly conical; metacoxae strongly transverse. Trochanters all short and lenticular. Femora clavate, tibiae long and slender, both covered in long setae. Tarsomeres long and slender; tarsomeres I–III similar in length, tarsomere IV slightly shorter and tarsomere V slightly longer. Tarsomeres covered in dense setae. Simple tarsal claws present.

Abdomen ( Fig. 2D View FIGURE 2 ) with unmodified sternites. Sternites of similar sizes, with sternite I and V being slightly larger than II–IV. Sternites I–V unmodified, whilst VI connate; suture between sternite V and VI shallow.

Aedeagus ( Fig. 2E–G View FIGURE 2 ) weakly asymmetrical in apical region (AeL = 0.17 mm). Parameres free and weakly expanding distally and long, extending past median lobe by approximately one-third of their total length. Parameres apices rounded, with singular long setae ( Fig. 3G View FIGURE 3 ). Internal structure somewhat preserved ( Fig. 2H View FIGURE 2 ), with basal pumping apparatus bearing medial sclerotized projection extending internally and evidence of muscle fibre attachments.

Paratype measurements (in mm): BL = 0.72, HL = 0.11, HW = 0.13, AnL = 0.30, PL = 0.18, PW = 0.17, EL = 0.43, EW = 0.30, EI = 1.45.

Etymology. The species epithet cantusfurca refers to the species’ aedeagal characteristics, with the parameres resembling the shape of a tuning fork. The epithet combines the Latin terms cantus for “song” and furca for “fork”.

Remarks — Alloraphes cantusfurca sp. nov. is placed in the genus Alloraphes according to the following set of characteristics from the revised genus diagnosis by Jałoszyński (2013): head subtriangular, vertex not expanded dorso-caudad; occipital constriction only slightly narrower than vertex; thick and long bristles absent on head but present on sides of prothorax; posterior margins of eyes adjacent to occipital constriction; submentum demarcated latterly from hypostomae by sutures; maxillary palpomere III strongly elongate, palpomere IV nearly four times long as broad at base; antennae with indistinctly delimited club composed of antennomeres IX–XI; base of pronotum with transverse groove connected at each end to shallow lateral impression or pit, without sub-lateral carinae; prothoracic hypomeral ridges complete; basisternal part of prosternum much shorter than procoxal cavites. In males, the aedeagus in ventral view ( Fig. 2G View FIGURE 2 ) has slight asymmetry in the apical region with a basal pumping apparatus bearing a medial sclerotized projection extending internally with evidence of muscle fibre attachments; parameres free. Syninclusion is identified as A.cantusfurca due to it sharing diagnostic characters and morphological traits with holotype ( Fig. 1 View FIGURE 1 ).