Anchylorhynchus vanini Valente & de Medeiros, 2013

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 : 56-58

Anchylorhynchus vanini Valente & de Medeiros, 2013

( Figures 4H , 8W , 13 F–G, 17C–D, 23D)

Anchylorhynchus vanini Valente & de Medeiros, 2013:395 , Figs.1–2 (description). Holotype: Male ; Projeto Níquel Vermelho, Canaã dos Carajás, Pará, Brazil (S6°28’32”, W49°52’27”); R. M. Valente col.; in inflorescence of “ Syagrus vermicularis ”. Deposited in MPEG, images examined.

Redescription. Male: Body size (length of elytra + pronotum) 7.0– 9.7 mm.

Head: Rostrum 1.2–1.4 times as long as pronotum; 1.4–1.5 times wider at apex than at base; integument brown to black; with seven longitudinal carinae (including a pair along scrobes), two lateralmost pairs of carinae indistinct near the base or distinct throughout their length; scrobes parallel to rostrum; apex covered by microsetae; areas between dorsal carinae covered by yellowish scales, narrow to setiform at base and setiform at the apex of rostrum, directed toward the central carina. Eyes 1.3–1.5 times as high as wide; 0.8–0.9 times more separated above than below. Head integument black or brown, similar to or darker than rostrum; covered by large yellowish scales only around the eyes and on the sides and dark microsetae elsewhere; scales directed to a point basal to the inter-ocular fovea. 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 wide as long and narrower than club; club about as long as antennomeres III–VI or IV–VI of the funicle. Left mandible straight at outer margin; dorsally with one large and one small seta; outer tooth forming a sharp angle or evenly connected to the mandible margin, with somewhat blunt apex; molar region straight. Left maxilla with stipes moderately elongate, with a long ventral seta; galeo-lacinial complex not reaching the apex of palpomere I; dorsal region with an acute angle at base; palpomere I with three apical setae shorter than the length of palpomere I; palpomere II approximately as long as palpomere I. Labium prementum distinctively narrower than postmentum, about 1.5 times as wide as long, lateral margins parallel in median region, with a right angle in lateral-apical region, with sparse setae not arranged in rows; ligula shorter than half of the length of prementum; palps separated by less than half the width of palpomere I; palpomere I approximately as long as wide; palpomere II approximately as long as palpomere III; palpomere III with one lateral seta.

Thorax: Pronotum width at base 2.0–2.2 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, lighter than head; entirely covered by uniformly yellowish scales; scales on disk directed to the apex. Profemur dorsal margin with curvature about as pronounced as ventral margin; tooth well-defined. Protarsus with short and dense setae on the ventral surface, without sparse and long setae on the sides. Scutellum 1.2–1.4 times longer than wide; integument brown to black, usually darker than elytra; scales yellowish to brown. Elytra 1.1–1.3 times wider than pronotum; 1.5–1.8 times longer than wide; 3.9–4.5 times longer than pronotum; humeri rounded; lateral margins subparallel, only slightly wider at middle; dorsal region with yellowish scales; epipleura with a distinct inflexion on interval IX, covered by yellowish scales similar to disk. Ventral region of thorax integument yellowish to brown, similar to dorsal region; scales pale yellow, distinctively lighter than those in pronotum. Hypomeron densely covered by mostly non-overlapping scales with acuminate apex narrower than those of pronotum; scales next to coxal cavities with size similar to others. Prosternum length 0.9–1.1 times the width of coxae; postocular lobes indistinct, with apical-lateral margin of prothorax regularly curved to slightly sinuate; covered by overlapping scales with acuminate 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 recumbent setae. Aedeagus about 3 times as long as wide; about 7 times as long as high; not wider at opening; with an acute anterior process; ventral plate thin and barely sclerotized, extending to approximately 0.4 times the length of the apodemes. Apodemes about 1.5 times as long as aedeagus. Endophallus membranous and slightly sclerotized in area anterior to the basal sclerite; microtrichae of the apical region not organized in bands.

Female: Body size 6.9–8.7 mm. Rostrum 1.2–1.4 times longer than pronotum; width at apex 1.4–1.5 times width at base. Eyes 1.4–1.5 times as high as wide; 0.7–0.9 times more separated above than below. Pronotum 1.8–1.9 times as wide at base as long; lateral margins in dorsal view converging from the base, with a marked inflexion at median region and a subtle apical constriction. Prosternum length 0.9–1.0 times the coxal width. Scutellum 1.1–1.7 times as long as wide. Elytra 1.4–1.6 times as wide as pronotum; 1.4–1.7 times as long as wide; 4.1–4.3 times as long as pronotum. Ventrites III and IV with posterior retraction not sinuate and reaching the middle of the segment.

Remarks. Anchylorhynchus vanini is very similar to Anchylorhynchus aegrotus and both can be easily distinguished from most other species of Anchylorhynchus by the elytra covered by yellowish to brown scales and variably reduced scales on head and pronotum revealing the punctures ( Figures 17 C–D, 7C). The shape of the pronotum, very wide in males and with a distinct inflexion in females, is also shared between A. aegrotus and A. vanini ( Figures 8A, 8W ). Males of A. vanini have a wider and less well-delimited metasternal concavity ( Figure 17C ) than males of A. aegrotus ( Figure 17B ). Females ( Figure 13G ) can be distinguished from A. aegrotus ( Figure 10B ) by the dark area on the pronotum. Finally, A. vanini is the only species of Anchylorhynchus with two long setae on the mandibles ( Figure 4H ). Most species have only one long external seta, while A. tricarinatus has three setae.

Geographical Distribution. This species is known only from the state of Pará, Brazil ( Figure 24 ), but its host plant is more widespread in transition zones between Amazonia and Cerrado.

Host Plants. Syagrus vermicularis Noblick

All specimens studied were directly collected from this species. Valente & de Medeiros (2013) report that A. vanini was searched in 19 other species of sympatric palms, including Syagrus inajai (Spruce) Becc. , Syagrus cocoides and species of Attalea Kunth , Astrocaryum G.Mey. , Bactris Jacq. ex Scop. , Euterpe , Geonoma Willd. , Mauritia L.f., Mauritiella Burret , Oenocarpus and Socratea H.Karst.

Examined Specimens. Type Material. BRAZIL. Pará: Canaã dos Carajás, Projeto Níquel Vermelho , R . M. Valente, 27/XI/2005 (♂ holotype Anchylorhynchus vanini MPEG); 07/V/2004 (1♂ paratype Anchylorhynchus vanini MZSP); 25/XI/2005 (3♀ paratypes Anchylorhynchus vanini MZSP); 27/XI/2005 (3♀, 3♂ paratypes Anchylorhynchus vanini CMNC, 1♀, 3♂ paratypes Anchylorhynchus vanini MZSP).

Other Material. BRAZIL. Pará: Canaã dos Carajás, Projeto Níquel Vermelho , R. M. Valente, 07/ V /2004 (1♂ MZSP); 25/XI/2005 (3♀ MZSP); 27/XI/2005 (2♀, 2♂ MZSP) .

Figures

FIGURE 1. Measurements taken and views used to take them, exemplified with a male of A. aegrotus. Scales: 500 µm. A Head, dorsal view: rostrum width at apex, rostrum width at base, distance between eyes above, head width. B Head, lateral view: rostrum length. C Head, ventral view: distance between eyes below. D Eye, frontal view: eye height and eye length. E Prothorax, dorsal view: prothorax length, prothorax width at base, scutellum length, scutellum width (in case scutellum at a different angle, an additional view with a detail of the scutellum was used). F Prosternum, ventral view: length of prosternum, coxal width. G Elytra, dorsal view: width of one elytrum. H Elytra, lateral view: length of elytra. I Proleg, lateral view: length of profemur, width of profemur, length of protibial, width of protibial. J Antenna, lateral view: length of scape, width of scape, length of each antennomere of the funicle, width of each antennomere of the funicle, length of club, width of club. K Male genitalia, dorsal view: width of aedeagus at base. L Male genitalia, lateral view: Length of aedeagus following the ventral curvature, length of ventral sclerotization beyond the insertion of apodemes, height of aedeagus, length of an apodeme following its curvature.

FIGURE 2. Heads of species of Anchylorhynchus. Scale: 500 µm. A A. centrosquamatus, male, showing five well-defined dorsal carinae in the rostrum and scales on the head directed to the interocular fovea. B A. centrosquamatus, male, showing the pairs of lateral carinae along the scrobe, totaling 7 carinae in the rostrum. C A. pinocchio, female, showing five dorsal carinae poorly defined towards the base. D A. pinocchio, female, showing the lateral carinae poorly defined towards the base. E A. aegrotus, showing scales in the head smaller and directed to the base of the head. F A. burmeisteri, showing scales in the head directed to the rostrum. G A. tricarinatus, male, showing three well-defined dorsal carinae. H A. tricarinatus, male, showing no lateral carinae. I A. bicarinatus, male, with three well-defined dorsal carinae. H A. bicarinatus, male, with only two dorsal carinae and no central carina.

FIGURE 4. Left mandibles of species of Anchylorhynchus (ventral view). Scales: 100 µm. A A. amazonicus. B A. trapezicollis. C A. tricarinatus D A. minimus. E A. tremolerasi. F A. variabilis. G A. aegrotus. H A. vanini.

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 10. Habitus of species of Anchylorhynchus. Some images are mirrored in relation to originals. Scales: 1 mm. A A. aegrotus (male) B A. aegrotus (female) C A. albidus D A. amazonicus (male holotype) E–F A. amazonicus (Canaã dos Carajás, Brazil) G A. bicarinatus H–K A. bicolor. Photographs in K provided by Roberta Valente based on specimens loaned from NHMUK. L A. bucki.

FIGURE 13. Habitus of species of Anchylorhynchus (continued). Scales: 1 mm. A–D A. tremolerasi. E A. tricarinatus. F A. vanini (male). G A. vanini (female). H A. variabilis (male). I–L A. variabilis (female).

FIGURE 17. Metathorax of species of Anchylorhynchus, ventral view. Scales: 500 µm. A A. trapezicollis. B A. aegrotus C A. vanini, male. D A. vanini, female.

FIGURE 24. Geographical distribution of species of Anchylorhynchus based on specimens examined, excluding suspicious locations as indicated in the main text. The distribution of A. parcus is unknown. A A. aegrotus, A. albidus, A. amazonicus, A. centrosquamatus. B A. bicarinatus, A. bicolor, A. burmeisteri, A. rectus. C A. bucki, A. goiano, A. imitator, A. luteobrunneus. D A. camposi, A. minimus, A. multisquamis, A. tremolerasi. E A. latipes, A. pinocchio, A. trapezicollis, A. vittipennis. F A. chrysomeloides, A. tricarinatus, A. vanini, A. variabilis.