Anchylorhynchus centrosquamatus de Medeiros & Núñez-Avellaneda, 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 : 32-33

Anchylorhynchus centrosquamatus de Medeiros & Núñez-Avellaneda, 2013

( Figures 2A , 8I , 9A , 11D , 21I )

Anchylorhynchus centrosquamatus de Medeiros & Núñez-Avellaneda, 2013:397 , Figs. 1C , 2B , 3B , 4 (description); Núñez-Avellaneda & Carreño, 2017:227, Table 2 (biology). Holotype: Male ; Vereda la Tigrana, Monterrey, Casanare, Colombia; 07/VIII/2009; L. Núñez & J. Carreño col.; in inflorescence of “ Syagrus orinocensis ”. Deposited in ICN, images examined.

Redescription. Males: Body size (length of elytra + pronotum) 5.3–5.9 mm.

Head: Rostrum 1.5–1.6 times as long as pronotum; 1.3–1.4 times wider at apex than at base; with integument brown to black; 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 narrow to setiform scales at base to setiform at apex, directed toward the central carina. Eyes 1.4–1.5 times as high as wide; 0.7 times more separated above than below. Head integument brown, lighter than rostrum; entirely covered by yellow scales directed to the inter-ocular fovea. Antennae with scape straight, clearly not reaching anterior eye margin; funicle: antennomere I of funicle only slightly wider than II, II longer than I and about 1.5 times as long as III, VI as wide as long and approximately as wide as club; club about as long as antennomeres IV–VI of funicle. Left mandible slightly sinuate at outer margin; with one dorsal seta; outer tooth not forming a sharp angle, with strongly acute apex; inner tooth well-developed; molar region straight. Left maxilla with stipes subquadrate, with a long ventral seta; galeo-lacinial complex extending beyond the apex of palpomere I; palpiger with elongate ventral region, dorsal region with an abtuse angle at base; palpomere I with three apical setae longer than the length of palpomere I; palpomere II approximately as long as palpomere I. Labium prementum almost as wide as postmentum, about 1.5 times as wide as long, lateral margins parallel in median region, lobed in lateral-apical region, with two oblique rows of setae in dorsal region; ligula about as long as half the length of prementum; palps separated by about half the width of palpomere I; palpomere I approximately as long as wide; palpomere II approximately as long as palpomere III; palpomere III with two lateral setae.

Thorax: Pronotum width at base 1.7 times pronotum length; base slightly lobed at middle; lateral margins in dorsal view convergent and regularly curved from base to apex, with a subtle apical constriction; integument brown, similar to head; entirely covered by uniformly yellowish scales directed to the center or to the basal half. Profemur approximately 3 times as long as wide; dorsal margin with curvature about as pronounced as ventral margin; tooth well-defined; about 2.5 times as wide as protibia. Protarsus tarsomere I about as long as tarsomere III; tarsomeres I and II slightly wider than long; with short and dense setae on the ventral surface and sparse and long setae on the sides. Scutellum 0.8–0.9 times longer than wide; integument brown, sometimes darker than elytra; scales yellowish. Elytra 1.4–1.5 times wider than pronotum; 1.4–1.5 times longer than wide; 3.5–3.6 times longer than pronotum; humeri with a well-defined angle; lateral margins distinctively 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 brown, similar to dorsal region; scales pale yellow, distinctively lighter than those in pronotum. Hypomeron densely covered by mostly non-overlapping scales with truncated apex, similar in shape to those in pronotum; scales next to coxal cavities larger. Prosternum length 1.1–1.2 times the width of coxae; postocular lobes indistinct, with apical-lateral margin of prothorax regularly curved to slightly sinuate; covered by overlapping acuminate scales, similar to 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 less than 2 times as long as wide; about 5 times as long as high; not wider at opening; with a truncated anterior process; ventral plate strongly sclerotized, extending to approximately 0.4 times the length of apodemes. Apodemes about 4 times as long as aedeagus. Endophallus with a pair of L-shaped sclerites anterior to the basal sclerite; with microtrichae of the apical region not organized in bands.

Female: Body size 4.7–5.7 mm. Rostrum 1.6–1.7 times longer than pronotum; width at apex 1.2–1.4 times width at base. Eyes 1.4 times as high as wide; 0.7 times more separated above than below. Pronotum 1.7–1.8 times as wide at base as long. Prosternum length 1.1–1.1 times the coxal width; Protarsus with two most proximal tarsomeres as long as wide. Protarsus without long setae; Scutellum 0.8–1.0 times as long as wide. Elytra 1.5–1.6 times as wide as pronotum; 1.4 times as long as wide; 3.8–3.9 times as long as pronotum. Ventrites III–V with recumbent narrow scales. Ventrites III and IV with posterior retraction not sinuate and restricted to the posterior end of the segment.

Remarks. This species ( Figure 11D ) is very similar in general appearance to Anchylorhynchus amazonicus ( Figures 10 D–F) and Anchylorhynchus imitator ( Figure 11G ). It can be distinguished from both by the median basal scales of pronotum obliquely directed toward center-base ( Figure 8I ). In A. amazonicus and A. imitator , these scales are clearly directed to the base ( Figures 8C, 8L ). It can also be mistaken for Anchylorhynchus trapezicollis by the elytra distinctly wider at middle and the trapezoidal pronotum. In the latter species, however, the third antennomere of the funicle is about as long as the second ( Figure 3F ), and the pronotal scales are directed to the apex ( Figure 8T ).

Geographical Distribution. This species is only known from the type locality in the department of Casanare, Colombia ( Figure 24 ) .

Host Plants. Syagrus orinocensis (Spruce) Burret.

This species is a minor pollinator of Syagrus orinocensis ( Núñez-Avellaneda & Carreño 2017) .

Examined Specimens. Type Material. COLOMBIA. Casanare: Monterrey, Vereda Tigrana, L. A. Núñez, 15/VII/2008 (2♀, 4♂ paratypes Anchylorhynchus centrosquamatus MZSP , 1♀, 1♂ paratypes Anchylorhynchus centrosquamatus CMNC , 1♀, 1♂ paratypes Anchylorhynchus centrosquamatus MPEG , 1♂ paratype Anchylorhynchus centrosquamatus AMNH ) .

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 3. Antennae of males of species of Anchylorhynchus. Scales: 500 µm. A A. bicolor. B A. chrysomeloides. C A. variabilis D A. minimus. E A. pinocchio. F A. trapezicollis. G A. latipes. H A. rectus. I A. albidus.

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 9. Prothorax of species of Anchylorhynchus, lateral view. Scales: 500 µm. A A. camposi. B A. rectus, showing larger scales next to coxal cavities. C A. bicarinatus, showing scales in the hypomeron larger than in the pronotum. D A. tricarinatus, showing scales in the hypomeron larger than in the pronotum. E A. goiano, showing larger scales next to coxal cavities. F A. multisquamis, showing dense vestiture in the hypomeron. G A. tremolerasi, female. H A. tremolerasi, male, showing sexual dimorphism with larger scales next to coxal cavities.

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 11. Habitus of species of Anchylorhynchus (continued). Some images are mirrored in relation to originals. Scales: 1 mm. A–B A. burmeisteri. C A. camposi. D A. centrosquamatus (from de Medeiros & Núñez-Avellaneda 2013). E A. chrysomeloides. F A. goiano. G A. imitator. H A. latipes I–K A. luteobrunneus (from de Medeiros & Núñez-Avellaneda 2013). L A. minimus.

FIGURE 21. Male genitalia of species of Anchylorhynchus. A. parcus is known only from the holotype, which was not dissected. Scales: 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 (reproduced from de Medeiros & Núñez-Avellaneda, 2013).

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.