Anchylorhynchus parcus Fahraeus, 1843

De, Bruno A. S. & Vanin, Sergio A., 2020, Systematic revision and morphological phylogenetic analysis of Anchylorhynchus Schoenherr, 1836 (Coleoptera, Curculionidae: Derelomini), Zootaxa 4839 (1), pp. 1-98 : 44-45

Anchylorhynchus parcus Fahraeus, 1843

( Figures 8Q , 12D )

Anchylorhynchus parcus Fahraeus in Schoenherr, 1843:335 (description); Lacordaire, 1863:520 (revision); Sherborn, 1929:4758 (cat.); Blackwelder, 1947:827 (cat.); Vaurie, 1954:14 (revision); Wibmer & O’Brien, 1986:196 (cat.). Holotype: Male; Brazil; Faldermann col. Deposited in NHRS, accession NHRS-JLKB 000027289, images examined.

Ancylorrhynchus parcus ; Gemminger & Harold, 1871:2545; Voss, 1943:63 (revision); Bondar, 1943a: 361 (revision).

Redescription. Male: Body size (length of elytra + pronotum) 4.2 mm.

Head: Rostrum 1.4 times as long as pronotum; 1.2 times wider at apex than at base; integument reddish-brown; with seven longitudinal carinae (including a pair along scrobes) distinct throughout their length; scrobes parallel to rostrum; apex covered by microsetae; areas between dorsal carinae covered by yellowish scales; scales narrow to setiform at base and setiform at the apex of rostrum, directed toward the central carina. Eyes 0.8 times more separated above than below. Head integument reddish-brown, similar to rostrum; entirely covered by yellowish scales and dark microsetae directed to the inter-ocular fovea, with. Antennae with scape straight, barely reaching anterior eye margin; funicle: antennomere I of funicle only slightly wider than II, II about as long as I and about 1.5 times as long as III, VI as long as wide and narrower than club; club as long as antennomeres II–VI of the funicle. Left mandible slightly sinuate at outer margin; with one dorsal seta; outer tooth forming a sharp angle with the mandible margin, with truncated apex; with inner tooth well-developed; molar region straight.

Thorax: Pronotum width at base 1.5 times pronotum length; base slightly lobed at middle; lateral margins in dorsal view parallel from base to median region, then convergent to apex, with a subtle apical constriction; integument brown, similar to head; entirely covered by uniformly yellowish scales; scales on disk directed to center or apex. Profemur approximately 3 times as long as wide; dorsal margin with curvature about as pronounced as ventral margin; tooth well-defined; about 3 times as wide as protibia. Protarsus tarsomere I about as long as tarsomere III; tarsomeres I and II as long as wide; with short and dense setae on the ventral surface and sparse and long setae on the sides. Scutellum 1.4 times longer than wide; integument brown, similar to elytra; scales yellowish. Elytra 1.7 times wider than pronotum; 1.3 times longer than wide; 3.2 times longer than pronotum; humeri with a well-defined angle; lateral margins subparallel, only slightly wider at middle; dorsal region with yellowish scales; epipleura without a marked inflexion on interval IX, covered by yellowish scales similar to disk. Ventral region of thorax integument reddish brown similar to dorsal region; scales similar or slightly lighter than dorsal region. Hypomeron covered by sparse scales with truncated apex, similar in shape to those in pronotum; scales next to coxal cavities larger. Prosternum length 0.7 times the width of coxae; postocular lobes indistinct, with apical-lateral margin of prothorax regularly curved to slightly sinuate; densely covered by mostly non-overlapping scales with truncated apex, narrower than those in pronotum. Metepisternum covered by non-overlapping scales, or overlapping only next to the anterior margin. Metasternum central concavity distinct; with very short setae in the center.

Abdomen: Ventrites III–V covered by narrow scales.

Remarks. This is species is only known from the holotype, lacking one elytrum ( Figure12D ). It can be distinguished from the other species with uniform yellow scales by the scales of the pronotum directed to the apex ( Figure 8Q ) (against towards the base or center for A. trapezicollis , A. goiano , A. latipes , A. camposi , A. rectus , A. amazonicus , A. centrosquamatus and A. imitator ), the lateral margins of the pronotum parallel at base (against converging for A. minimus ), the rostrum brown (against black for A. albidus and A. pinocchio ) and with seven carinae (against 2–3 carinae for A. bicarinatus and A. tricarinatus ).

Geographical Distribution. The holotype was collected in Brazil, locality unknown

Fahraeus states that the type specimen was donated by Faldermann ( Schoenherr 1843), which indicates that the sample was obtained from a Russian expedition to Brazil taking place a few years earlier ( Faldermann 1831). This expedition covered most of the biomes in the country, so the type locality of this species cannot be known from this information alone. Considering that no other specimens have been collected since then and we did not find additional material for the species in our own extensive sampling, we find it likely that the host species is either a highly endemic Syagrus species in a hilltop vegetation (“campos rupestres”) within the cerrado biome or an Amazonian species not sampled by us.

Host Plants. Unknown. Ancestral state reconstruction indicates a species of Butia ( Figure 27 ).

Examined Specimens. Type Material. BRAZIL. No region: No locality, Faldermann , no date (♂ holotype Anchylorhynchus parcus NHRS) .

Figures

FIGURE 8. Prothorax of all Anchylorhynchus species. Except for A. parcus, only known from the male holotype, the thorax of a male (left) and a female (right) are shown for each species. Arrows show the direction of scales in each position. Scale: 500 µm. A A. aegrotus. B A. albidus. C A. amazonicus. D A. bicarinatus. E A. bicolor. F A. bucki. G A. burmeisteri. H A. camposi. I A. centrosquamatus (from de Medeiros & Núñez-Avellaneda 2013). J A. chrysomeloides. K A. goiano. L A. imitator. M A. latipes. N A. luteobrunneus (from de Medeiros & Núñez-Avellaneda 2013). O A. minimus. P A. multisquamis. Q A. parcus. R A. pinocchio (from de Medeiros & Núñez-Avellaneda 2013). S A. rectus. T A. trapezicollis U A. tremolerasi V A. tricarinatus W A. vanini X A. variabilis Y A. vittipennis.

FIGURE 12. Habitus of species of Anchylorhynchus (continued). Some images are mirrored in relation to originals. Scales: 1 mm. A A. multisquamis. B A. pinocchio (male). C A. pinocchio (female). D A. parcus (male holotype). Photographed by Johannes Bergsten © 2017 Naturhistoriska riksmuseet. Background removed from original photo, light levels and contrast adjusted. Made available by the Swedish Museum of Natural History under CC-BY 4.0 international license. E A. rectus. F A. trapezicollis. G–L A. tremolerasi.

FIGURE 27. Ancestral state reconstruction for the association with host plant genus on the Bayesian tree.