Anchylorhynchus luteobrunneus 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 : 39-41

Anchylorhynchus luteobrunneus de Medeiros & Núñez-Avellaneda, 2013

( Figures 8N , 11 I–K, 22E)

Anchylorhynchus luteobrunneus de Medeiros & Núñez-Avellaneda, 2013:399 , Figs. 1 D–F, 2C, 3C (description). Holotype: Male ; Corregimiento Morichal, Yopal, Casanare, Colombia; 30-IX-2010; L. Núñez & J. Carreño col.; in flowers of “ Syagrus sancona ”. Deposited in ICN, images examined.

Redescription. Male: Body size (length of elytra + pronotum) 3.9–4.7 mm.

Head: Rostrum 1.4–1.6 times as long as pronotum; 1.2–1.3 times wider at apex than at base; integument brown to black; with seven longitudinal carinae (including a pair along scrobes), the pair of carinae along the scrobes indistinct near the base; scrobes parallel to rostrum; apex covered by narrow and elongate scales; areas between dorsal carinae covered by wide yellowish to brown scales, distinctively narrower towards the apex of rostrum, directed toward the central carina. Eyes 1.3 times as high as wide; 0.7–0.9 times more separated above than below. Head integument brown to black, similar to rostrum; entirely covered by black, brown or yellow scales directed 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 longer than I and about 2 times as long as III; VI as wide as long and narrower than club; club as long as antennomeres III–VI of the funicle. Left mandible straight 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 moderately elongate, with a long ventral seta; galeo-lacinial complex almost reaching the apex of palpomere I; palpiger with elongate ventral region, dorsal region forming with abtuse angle at base; palpomere I with two apical setae longer than the length of palpomere I; palpomere II approximately as long as palpomere I. Labium prementum slightly narrower than postmentum, about 2 times as wide as long, lateral margins parallel in median region, with a right angle in lateral-apical region, with two oblique rows of setae in dorsal region; ligula shorter than half of the length of prementum; palps separated by about half the width of palpomere I; palpomere I transverse; palpomere II shorter than palpomere III; palpomere III with one lateral seta.

Thorax: Pronotum width at base 1.4–1.5 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, lighter than head; scale colors vary: uniformly yellow scales, or yellow scales on disk and narrow longitudinal bands of brown scales on the sides, or brown scales on most of the area and narrow rows of yellow scales on lateral margins and at the base; scales basal half of disk directed to the base. Profemur approximately 4 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 distinctively longer than tarsomere III; tarsomeres I and II longer than wide; with short and dense setae on the ventral surface and sparse and long setae on the sides. Scutellum 1.0–1.1 times longer than wide; integument brown to black; scales entirely yellowish or yellowish at base and on the sides and brown in the middle. Elytra 1.4–1.6 times wider than pronotum; 1.4–1.6 times longer than wide; 3.0–3.4 times longer than pronotum; humeri rounded; lateral margins subparallel, only slightly wider at the middle; scale color varies: uniformly yellow scales, or sides and apex with brown scales interspersed by yellow scales, or entirely covered by brown to black scales interspersed by yellow scales; epipleura without a marked inflexion on interval IX, covered by dark scales or concolor with disk. Ventral region of thorax integument yellowish to black; scales pale yellow, distinctively lighter than those in pronotum. Hypomeron densely covered by mostly non-overlapping scales with apex truncated to acuminate similar in shape to those in pronotum; scales next to coxal cavities with size similar to others. 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 scales, with acuminate scales similar to those in pronotum. Metepisternum entirely covered by overlapping scales. Metasternum central concavity subtle; with long setae in the center.

Abdomen: Ventrites III–V covered by recumbent setae. Aedeagus 2–2.5 times as long as wide; about 6 times as long as high; not wider at opening; with an acute anterior process; ventral plate strongly sclerotized, extending to approximately 0.4 times the length of apodemes. Apodemes about 2.5 times as long as aedeagus. Endophallus membranous and slightly sclerotized in area anterior to basal sclerite; microtrichae of the apical region not organized in bands.

Female: Body size 4.3–4.8 mm. Rostrum 1.4–1.6 times longer than pronotum; width at apex 1.2–1.3 times width at base. Eyes 1.4–1.5 times as high as wide; 0.7 times more separated above than below. Pronotum 1.4–1.5 times as wide at base as long; lateral margins in dorsal view parallel at based and evenly curved to apex. Prosternum length 1.1–1.2 times the coxal width. Protarsus without long setae; Scutellum 1.1–1.2 times as long as wide. Elytra 1.5–1.6 times as wide as pronotum; 1.4–1.6 times as long as wide; 3.4–3.6 times as long as pronotum. Ventrites III and IV with posterior retraction not sinuate and reaching the middle of the segment.

Remarks. Specimens with dark brown scales ( Figures 11 J–K) can be distinguished from other Anchylorhynchus by the unique color pattern. The combination of wide (1.4–1.6 times longer than wide) elytra with parallel margins, basal pronotal scales directed to the base ( Figure 8N ), seven rostral carinae (with those along the scrobe indistinct near base as in Figure 2D ) and pronotal margins parallel at base ( Figure 8N ) may further distinguish the yellow-colored specimens from any other species of Anchylorhynchus .

Geographical Distribution. This species is known only from the type locality ( Figure 24 ). Host plant occurs in lowland rainforests, gallery forest and piedmont forests in Colombia (Casanare, Meta and Guaviare), at elevations ranging from 100 to 1000 m ( de Medeiros & Núñez-Avellaneda 2013) .

Host Plants. Syagrus sancona H. Karst.

Núñez-Avellaneda (2014) found 10–55 individuals per inflorescence of Syagrus sancona , with A. luteobrunneus being one of the main pollinators of the species.

Examined Specimens. Type Material. COLOMBIA. Casanare: Sabanalarga , Vereda Piñal, L. A. Núñez , 10/ VIII/2010 (7♀, 4♂ paratypes Anchylorhynchus luteobrunneus MZSP , 1♀ paratype Anchylorhynchus luteobrunneus NHMUK ); 15/VIII/2008 (1♂ paratype Anchylorhynchus luteobrunneus MZSP ); 19/X/2009 (5♀, 2♂ paratypes Anchylorhynchus luteobrunneus MZSP , 1♀ paratype Anchylorhynchus luteobrunneus AMNH ); Yopal, Corregimiento Morichal, L. A. Núñez, 6/XI/2008 (5♀, 11♂ paratypes Anchylorhynchus luteobrunneus MZSP ); 17/XI/2010 (7♀, 2♂ paratypes Anchylorhynchus luteobrunneus MZSP , 1♀, 1♂ paratypes Anchylorhynchus luteobrunneus CMNC , 1♂ paratype Anchylorhynchus luteobrunneus NHMUK , 1♂ paratype Anchylorhynchus luteobrunneus 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 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 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 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.