Anchylorhynchus bicarinatus O’Brien, 1981

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 : 22-24

Anchylorhynchus bicarinatus O’Brien, 1981

( Figures 2 I–J, 7B, 8D, 9C, 10G, 15A, 20C–D, 21D)

Anchylorhynchus bicarinatus O’Brien, 1981:501 , Figs. 1–5 (description); O’Brien & Wibmer 1982:96 (cat.); Núñez-Avellaneda et al. 2015:42, 49, Fig. 4 (biology). Holotype: Male; Canal Zone, Barro Colorado Island, Panama; 30-X-1976; H. Wolda col. Deposited in ASUCOB, specimen examined.

Anchylorhynchus gottsbergerorum Vanin, 1995:878 , Figs. 15–20 (description) [new synonym]. Holotype: Male ; Reserva Ducke, Amazonas, Brazil; 14-III-1993; Heike Küchmeister col. Deposited in INPA, not examined.

Redescription. Male: Body size (length of elytra + pronotum) 2.5–4.3 mm.

Head: Rostrum 1.2–1.4 times as long as pronotum; 1.2–1.4 times wider at apex than at base; integument brown to black; with two or three longitudinal indistinct carinae; scrobes parallel to rostrum; apex covered by narrow and elongate scales; areas between dorsal carinae covered by dense wide yellowish scales directed toward the base of the rostrum, only slightly narrower towards the apex of rostrum. Eyes 1.3–1.4 times as high as wide; 0.5–0.8 times more separated above than below. Head with integument brown, similar to or lighter than rostrum; entirely covered by scales; scales directed to the inter-ocular fovea, yellow. Antennae with scape straight, barely reaching anterior eye margin; funicle: antennomere I about 1.5 times wider than II, II longer than I and about 2 times as long III, VI as wide as long and narrower than the club; club about as long as the antennomeres IV–VI of funicle. Left mandible straight on outer margin; with one dorsal seta; outer tooth not forming a sharp angle, with strongly acute apex; inner tooth well-developed; molar region slightly concave. Left maxilla with stipes subquadrate, with a long ventral seta; galeo-lacinial complex almost reaching the apex of palpomere I; palpiger with ventral region about as long as wide, dorsal region forming an acute 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 with prementum almost as wide as postmentum, about 1.5 times as wide as long, lateral margins parallel in median region, with a right angle in lateral-apical region, with a median longitudinal row of short setae in dorsal region; ligula present and about half the length of prementum; palps separated by about half the width of palpomere I; palpomere I longer than wide; palpomere II longer than palpomere III; palpomere III with one lateral seta.

Thorax: Pronotum width at base 1.4–1.7 times pronotum length; base slightly lobed at middle; lateral margins in dorsal view parallel from base to median region, then convergent to apex, without apical constriction; integument brown, lighter than head; entirely covered by uniformly yellowish scales; scales on the disk 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 with 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, without sparse and long setae on the sides. Scutellum 0.9–1.5 times longer than wide; integument brown, the same color as elytra; scales yellowish. Elytra 1.5–1.8 times wider than pronotum; 1.4–1.6 times longer than wide; 3.5–4.0 times longer than pronotum; humeri rounded; lateral margins subparallel, only slightly wider at middle; dorsal region with yellowish scales; epipleura without a marked inflexion on interval IX, scales with the same color as disk. Ventral region of thorax integument brown with similar color to dorsal region; scales yellowish, similar or slightly lighter than dorsal region. Hypomeron densely covered by mostly non-overlapping truncated to acuminate scales similar in shape to those in pronotum; scales next to coxal cavities with size similar to others. Prosternum length 0.7–0.8 times the width of coxae; postocular lobes distinct, with the apical lateral margin of prothorax clearly sinuate; covered by overlapping acuminate scales wider than those in pronotum. Metepisternum covered by nonoverlapping scales, or overlapping only next to anterior margin. Metasternum central concavity subtle; covered by scales in the center.

Abdomen: Ventrites III–V covered by narrow scales. Aedeagus less than 2 times as long as wide; about 5 times as long as high; not 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 a longitudinal slightly sclerotized area next to the posterior margin of aedeagus; microtrichae of the apical region not organized in bands.

Female: Body size 2.6–4.3 mm. Rostrum 1.2–1.5 times longer than pronotum; width at apex 1.3–1.5 times width at base. Eyes 1.5–1.5 times as high as wide; 0.6–0.6 times more separated above than below. Pronotum 1.4–1.7 times as wide at base as long. Prosternum length 0.7–0.8 times the coxal width. Scutellum 1.2–1.5 times as long as wide. Elytra 1.4–1.7 times as wide as pronotum; 1.5–1.8 times as long as wide; 3.6–4.2 times as long as pronotum. Ventrites III and IV with posterior retraction not sinuate and restricted to the posterior end of the segment.

Remarks. Anchylorhynchus bicarinatus can be distinguished by the small size (less than 5 mm pronotum + elytra), elytra much wider than pronotum ( Figure 10G ) and not more than three longitudinal carinae in the rostrum ( Figures 2 I–J). The only other species with a reduced number of carinae is A. tricarinatus ( Figure 2 G–H), which has a larger body size (5.7–6.1 mm). O’Brien (1981) described A. bicarinatus as always having two carinae on the rostrum and brown to black rostrum. Vanin (1995) described A. gottsbergerorum as a new species distinguished by having three dorsal carinae and rostrum yellowish-brown as the head. In reality, both characters are variable, with the median carina being variably developed and rostrum varying from distinctly darker to similar in color to the head in all populations analysed. The male genitalia of both are indistinguishable. For that reason, the latter species is considered as a junior synonym here. Núñez-Avellaneda et al. (2015) identified the pollinators of Oenocarpus minor Mart. as A. bicarinatus and considered them to be a different species from sympatric samples from Oenocarpus balickii F.Kahn. There is no reliable diagnostic morphological character distinguishing these putative species. Due to the lack of diagnostic characters, here we consider all of these to be Anchylorhynchus bicarinatus , which is the senior synonym by priority. Additional work with more extensive sampling and molecular methods might reveal that some of these forms are separate, cryptic species.

Geographical Distribution. This species occurs throughout the Amazon basin and in Panama, where species of Oenocarpus can be found ( Figure 24 ).

Host Plants. Oenocarpus bacaba Mart. , oenocarpus balickii F.Kahn , oenocarpus distichus Mart. , oenocarpus minor Mart , Oenocarpus mapora H.Karst.

Núñez-Avellaneda et al. (2015) collected them from Oenocarpus balickii F.Kahn and Oenocarpus minor Mart. in Leticia , Amazonas, Colombia. The type locality (Barro Colorado Island, Panama) has a single species of Oenocarpus ( Oenocarpus mapora H.Karst., STRI 2015 ), the host in that region. Specimen labels indicate that this species was sampled from flowers of Oenocarpus bacaba Mart. and Oenocarpus minor Mart. in Reserva Ducke, Amazonas, Brazil and Oenocarpus distichus Mart. in Caxiuanã, Pará, Brazil.

Examined Specimens. Type Material. PANAMA. Panamá: Barro Colorado Island , H. Wolda , 30/X/1976 (♂ holotype Anchylorhynchus bicarinatus ASUCOB); 03/III/1978 (1♀ paratype Anchylorhynchus bicarinatus STRI); 05/XI/1976 (1♀, 2♂ paratypes Anchylorhynchus bicarinatus USNM) ; 07/I/1978 (1♀ paratype Anchylorhynchus bicarinatus STRI); 10/X/1976 (1♀ paratype Anchylorhynchus bicarinatus FMNH); 10/XII/1977 (1♀ paratype Anchylorhynchus bicarinatus STRI); 16/IX/1976 (1♀ paratype Anchylorhynchus bicarinatus FMNH); 17/I/1978 (1♀ paratype Anchylorhynchus bicarinatus STRI); 18/IX/1976 (1♀ paratype Anchylorhynchus bicarinatus FMNH); 20/ IX/1976 (1♀ paratype Anchylorhynchus bicarinatus FMNH); 21/IX/1976 (1♀ paratype Anchylorhynchus bicarinatus FMNH); 22–23/IX/1978 (1♀ paratype Anchylorhynchus bicarinatus STRI); 22/IX/1976 (1♂ paratype Anchylorhynchus bicarinatus FMNH); 22/IX/1978 (1♀, 1♂ paratypes Anchylorhynchus bicarinatus STRI); 26/XI/1976 (2♂ paratypes Anchylorhynchus bicarinatus USNM).

BRAZIL. Amazonas: Manaus , Reserva Ducke, H. Kuchmeister, 15/IV/1992 (1♀ paratype Anchylorhynchus gottsbergerorum MZSP); G. Gottsberger, 26/III/1993 (1♀, 1♂ paratypes Anchylorhynchus gottsbergerorum MZSP); H. Kuchmeister, 28/III/1993 (1♂ paratype Anchylorhynchus gottsbergerorum MZSP) .

Other Material. BRAZIL. Amazonas: Manaus, Reserva Ducke, Barbosa, M. G. V ., VII /1995 (1♀ MZSP); H. Kuchmeister, 02/VI /1993 (1♂ MZSP); 07/VII /1993 (1♀, 2♂ MZSP); 15/VI /1993 (1♀, 2♂ MZSP). Pará: Caxiuanã (Melgaço), R . M. Valente, 10/XI/2006 (2♀ MZSP); Caxiuanã, ECFPn, R . M. Valente, 23/VIII/1995 (6♂ MZSP); 24/VIII/1995 (6♀, 2♂ MPEG, 1♀, 1♂ MZSP); 28/VIII/1995 (3♀, 1♂ MPEG) .

COLOMBIA. Amazonas: Leticia, LA Núñez & B. A. S. Medeiros, 02/ V /2014 (1♀, 1♂, 90 sex undetermined MZSP); 29/IV/2014 (129 sex undetermined MZSP) . Casanare: Monterrey, Vereda Tigrana, L. A. Núñez, 28/ VIII/2009 (1♀, 1♂ MPEG, 6♀, 2♂ MZSP) .

PANAMA. Panamá: Barro Colorado Island , H. P. Stockwell, 04/ VI /1974 (1♀ STRI) ; H. Wolda, 05–06/XI/1977 (1♂ STRI) ; 25/I/1975 (1♀ STRI) ; WD & SS Duckworth, 18–28/IV/1964 (1♀ USNM) ; Las Cumbres, H. Wolda, 14/II/1975 (2♀ STRI) .

PERU. Madre de Dios: Puerto Maldonado, Rio Tambopata , J. B. Heppner, 06–10/XI/1979 (2♂ USNM); 21– 25/XI/1979 (2♀ USNM) .

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 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 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 15. Prosterna of species of Anchylorhynchus, ventral view. Scales: 500 µm. A A. bicarinatus. B A. camposi. C A. chrysomeloides. D A. variabilis.

FIGURE 16. Meso- and metathorax of species of Anchylorhynchus, lateral view. Scales: 500 µm. A A. camposi. B A. burmeisteri. C A. multisquamis. D A. variabilis.

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 18. Prolegs of species of Anchylorhynchus. Scales: 500 µm. A A. burmeisteri, male. B A. camposi, male. C A. multisquamis, male. D A. minimus, male. E A. pinocchio, male. F A. tricarinatus, male. G A. variabilis, male. H A. trapezicollis, male. I A. trapezicollis, female. J A. latipes, male. K A. latipes, female.

FIGURE 19. Male ventrites of species of Anchylorhynchus. Scales: 500 µm. A A. amazonicus, showing recumbent hairs. B A. amazonicus, showing a morph with less elongate scales. C A. imitator, showing that scales on ventrites are never as elongate as in A. amazonicus. D A. goiano. E A. vittipennis. F A. variabilis.

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 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.