Anchylorhynchus bucki Vanin, 1973

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 : 26-28

Anchylorhynchus bucki Vanin, 1973

( Figures 5F , 6H , 8F , 10L , 20B , 21F .)

Anchylorhynchus bucki Vanin, 1973:37 (description); Wibmer & O’Brien, 1986:195 (cat.). Holotype: Male; Itu, São Paulo, Brazil; 7-XII-1960; U. Martins col.; in “coco” flower (“em flor de coqueiro”). Deposited in MZSP, examined.

Redescription. Male: Body size (length of elytra + pronotum) 4.9–5.7 mm.

Head: Rostrum 0.7–0.8 times as long as pronotum; 1.3–1.4 times wider at apex than at base; integument yellowish to dark 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 wide scales, distinctively narrower towards the apex of rostrum and directed toward the central carina. Eyes 1.9–1.9 times as high as wide; 0.7 times more separated above than below. Head integument concolor with rostrum; entirely covered by large yellow scales or with large scales only around eyes and at sides and by microsetae elsewhere; scales directed to a point basal to the inter-ocular fovea. Antennae with scape straight, barely reaching the anterior eye margin; funicle: antennomere I only slightly wider than II, II shorter than I and about 1.5 times as long as III, VI longer than wide and narrower than the club; club about as long as antennomeres IV–VI of funicle. Left mandible straight at outer margin; with one dorsal seta; outer tooth not forming a sharp angle, with rounded apex; inner tooth absent or weakly developed; molar region straight. Left maxilla with stipes moderately elongate, with a long ventral seta; galeo-lacinial complex extending beyond the apex of palpomere I; palpiger with transverse ventral region, dorsal region with acute angle at base; palpomere I with two apical setae shorter than the length of palpomere I; palpomere II approximately as long as palpomere I. Labium prementum slightly narrower than postmentum, about 1.5 times as wide as long, lateral margins parallel in median region, angled in lateral-apical region, with sparse setae not arranged in rows; ligula shorter than half of 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 one lateral seta.

Thorax: Pronotum width at base 1.4–1.5 times pronotum length; base not lobed at middle; lateral margins in dorsal view parallel at base and regularly curved to apex, without apical constriction; integument brown, similar to head; entirely covered by scales; with yelllowish scales on the sides and a longitudinal median band of brown scales extending to the elytra and scutellum; scales on the disk directed to the base in 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 with 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, without sparse and long setae on the sides. Scutellum 0.9–1.2 times longer than wide; integument brown, the same color as elytra; scales brown. Elytra 1.2–1.3 times wider than pronotum; 1.6–1.7 times longer than wide; 2.8–3.1 times longer than pronotum; humeri with a well-defined angle; lateral margins subparallel, only slightly wider at the middle; with one longitudinal band of brown scales on the basal fourth of intervals I and II and yellowish scales elsewhere; epipleura without a marked inflexion on interval IX, covered by dark scales. Ventral region of thorax integument color similar to sides of pronotum; scales with color similar to or slightly lighter than sides of pronotum. Hypomeron covered by sparse scales narrower than those of pronotum; scales with apex truncated to acuminate, those next to coxal cavities larger. Prosternum length 0.8 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 narrower than those in pronotum, with acuminate or truncated apex. Metepisternum covered by non-overlapping scales, or overlapping only next to the anterior margin. Metasternum without a central concavity; with very short setae in the center.

Abdomen: Ventrites III–V covered by recumbent setae. Aedeagus 2–2.5 times as long as wide; about 5 times as long as high; slightly wider at opening; with an acute anterior process; ventral plate thin and barely sclerotized, extending to approximately 0.3 times the length of apodemes. Apodemes about 2 times as long as aedeagus. Endophallus membranous and slightly sclerotized in area anterior to the basal sclerite; with microtrichae of apical region not organized in bands.

Female: Body size 4.7–6.0 mm. Rostrum 0.8 times longer than pronotum; width at apex 1.4–1.5 times width at base. Eyes 1.7–1.8 times as high as wide; 0.8–0.9 times more separated above than below. Pronotum 1.4–1.5 times as wide at base as long. Prosternum length 0.9–1.0 times the coxal width. Scutellum 0.9–1.5 times as long as wide. Elytra 1.3–1.4 times as wide as pronotum; 1.6–1.7 times as long as wide; 3.1–3.4 times as long as pronotum. Ventrites III and IV with posterior retraction not sinuate and restricted to the posterior end of the segment.

Remarks. This species can be distinguished by the very short rostrum (0.7–0.8 times as long as the pronotum) and by the color pattern with a band of brown scales extending from the pronotum to the basal fourth of the elytra ( Figure 10L ). Some individuals of A. aegrotus have a similar band of brown scales (e. g. Figure 10A ), but in that case it does not extend until the basal fourth of the elytra and the rostrum is longer (at least as long as the pronotum). Anchylorhynchus bucki also has a more elongate shape than A. aegrotus and most species of Anchylorhynchus .

Geographical Distribution. This species is known from savannas (cerrado) in the states of São Paulo, Minas Gerais and Goiás, Brazil ( Figure 24 ).

Host Plants. Syagrus deflexa Noblick & Lorenzi (voucher SPF B.A.S. Medeiros 323), Syagrus macrocarpa Barbr. Rodr. (voucher SPF B.A.S. Medeiros 113)

Likely: Syagrus loefgrenii Glassman or Syagrus flexuosa (Mart.) Becc.

We collected this species from Syagrus deflexa and Syagrus macrocarpa . The type series was obtained from flowers of a small unidentified palm in cerrado in the state of São Paulo (U. Martins, personal communication). Both S. loefgrenii and S. flexuosa are small cerrado palms closely related to the other known hosts that occur in the region of the type locality ( Noblick 2017).

Examined Specimens. Type Material. BRAZIL. São Paulo: Itu, U. Martins , 07/XII/1960 (♂ holotype Anchylorhynchus bucki MZSP , 3♀, 3♂ paratypes Anchylorhynchus bucki MZSP ); 13/XI/1960 (2♀ paratypes Anchylorhynchus bucki MZSP )

Other Material. BRAZIL. Goiás: Alto Paraíso de Goiás , B. A. S. Medeiros & G. P. Murayama, 26/XI/2014 (2 sex undetermined MZSP) . Minas Gerais: Paracatu, D. B. Thomas, 22/I/1980 (1♂ ASUCOB) ; Turmalina, B. A. S. Medeiros & F. M. Gudin, 04/XII/2013 (3 sex undetermined MZSP) .

Figures

FIGURE 5. Left maxillae of species of Anchylorhynchus (ventral view). Scales: 50 µm. A A. amazonicus. B A. trapezicollis. C A. tricarinatus. D A. minimus. E A. tremolerasi. F A. bucki. G A. aegrotus. H A. vittipennis. I A. variabilis.

FIGURE 6. Labia of species of Anchylorhynchus (dorsal view). Scales: 50 µm. Palp setae illustrated only on left side and lateral-apical setae of prementum only on right side. A A. amazonicus. B A. trapezicollis. C A. minimus. D A. pinocchio. E A. tricarinatus. F A. tremolerasi. G A. bicolor. H A. bucki. I A. aegrotus J A. variabilis.

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 20. Ventrites of species of Anchylorhynchus. Retraction of ventrites III–IV is shown in grey. Scales: 500 µm. A A. amazonicus, female. B A. bucki, female. C A. bicarinatus, female. D A. bicarinatus, male. E A. bicolor, female. F A. vittipennis. G A. variabilis, female. H A. variabilis, male.

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.