Anchylorhynchus bicolor Voss 1943
Creators: name: De, Bruno A. S.
name: Vanin, Sergio A.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Curculionidae
Anchylorhynchus
Anchylorhynchus bicolor

description: Anchylorhynchus bicolor Voss, 1943
(Figures 3A, 8E, 10 H–K, 21E)
Ancylorrhynchus parcus bicolor Voss, 1943: 64 (description in key). Lectotype (designated by Vaurie, 1954): Male; Paraguay; coll. Kraatz. Deposited in DEI, examined.
Anchylorhynchus bicolor; Vaurie, 1954: 28, Fig.3E (revision, status nov. and lectotype designation); Viana, 1975:14, Figs. 2, 5, 10 e 12 (revision); Wibmer & O’Brien, 1986:195 (cat.)
Ancylorrhynchus leiospathae Bondar, 1950:454, Fig. 7 (description). Lectotype (designated by Vaurie, 1954): Male; Pirassununga, São Paulo, Brazil; X-1949; Bondar col.; in Cocos leiospatha. Deposited in FMNH, examined.
Anchylorhynchus leiospathae; Wibmer & O’Brien, 1986:195 (cat.); Vaurie, 1954:28 (revision, synonymy with Anchylorhynchus bicolor, lectotype designation).
Redescription. Male: Body size (length of elytra + pronotum) 4.5–7.1 mm.
Head: Rostrum 1.3–1.4 times as long as pronotum; 1.2–1.3 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 wide yellowish to orange scales directed toward the central carina, distinctively narrower towards the apex of rostrum. Eyes 1.5–1.7 times as high as wide; 1.6–1.7 times more separated above than below. Head with integument yellowish to dark brown and similar to rostrum; entirely covered by yellow to orange scales directed to the inter-ocular fovea. Antennae with scape straight, barely reaching the anterior eye margin; funicle: antennomere I of funicle only slightly wider than II; II shorter than I and about 1.5 times as long as III; VI wider than long and narrower than club; club as long as the whole funicle. Left mandible strongly sinuate at outer margin; with one dorsal seta; outer tooth forming a sharp angle with the mandible margin, with somewhat blunt apex; inner tooth well-developed; molar region straight. Left maxilla with stipes strongly elongate, with a long ventral seta; galeo-lacinial complex not reaching the apex of palpomere I; palpiger with transverse ventral region, dorsal region with an acute angle at base; palpomere I with two apical setae longer than the length of palpomere I; palpomere II longer than palpomere I. Labium with prementum slightly narrower than postmentum, about 2 times as wide as long, lateral margins parallel in median region, angled in lateral-apical region, with a median longitudinal row of short setae in dorsal region and with very long setae on the sides of dorsal region; ligula absent; palps separated by less than half the width of palpomere I; palpomere I transverse; palpomere II longer than palpomere III; palpomere III with one lateral seta.
Thorax: Pronotum width at base 1.6–1.7 times pronotum length; base not lobed at middle; lateral margins in dorsal view parallel at base and regularly curved to apex, with a subtle apical constriction; integument brown, similar to the head; entirely covered by orange scales in the disk and orange to yellow on the sides, with or without a pair of dark spots; scales on the disk directed to the apex. Profemur approximately 3 times as long as wide; dorsal margin with curvature about as pronounced as ventral margin; tooth well-defined; about 2 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 0.9–1.1 times longer than wide; integument brown, the same color as elytra; scales yellow to orange. Elytra 1.3–1.4 times wider than pronotum; 1.4–1.6 times longer than wide; 3.2–3.4 times longer than pronotum; humeri with a well-defined angle; lateral margins subparallel, only slightly wider at middle; with uniformly yellowish scales, or with brown scales on even intervals and yellowish scales on odd intervals, or black scales and yellow longitudinal bands on intervals I and VII; epipleura without a marked inflexion on interval IX, covered by dark scales. Ventral region of thorax integument with similar color to dorsal region; scales slightly lighter or similar to sides of pronotum. Hypomeron covered by sparse scales with truncated apex, similar in shape to those in pronotum; scales next to coxal cavities larger. Prosternum length 0.9–0.9 times the width of coxae; postocular lobes indistinct, with apical-lateral margin of prothorax regularly curved to slightly sinuate; covered by overlapping scales, with scales similar to or slightly wider than those in pronotum, with truncated apex. Metepisternum covered by non-overlapping scales, or overlapping only next to the anterior margin. Metasternum central concavity subtle; with very short setae in the center.
Abdomen: Ventrites III–V covered by narrow scales. Aedeagus about 3 times as long as wide; about 6 times as long as high; slightly wider at opening; without an anterior process; ventral plate strongly sclerotized, extending to approximately 0.4 times the length of apodemes. Apodemes about 1.5 times as long as aedeagus. Endophallus with two pairs of membranous pockets containing microtrichae next to the basal sclerite; microtrichae of the apical region organized in a pair of bands, apparently the result of folds in membranes in this area.
Female: Body size 5.4–6.4 mm. Rostrum 1.3–1.5 times longer than pronotum; width at apex 1.2–1.3 times width at base. Eyes not measured. Pronotum 1.5–1.6 times as wide at base as long. Prosternum length 0.9–1.0 times the coxal width. Scutellum 0.9–1.2 times as long as wide. Elytra 1.3–1.5 times as wide as pronotum; 1.4–1.6 times as long as wide; 3.0–3.4 times as long as pronotum. Ventrites III and IV with posterior retraction not sinuate and reaching the middle of the segment.
Remarks. Anchylorhynchus bicolor can be easily distinguished by the antennal club as long as the funicle (Figure 3A). The club is always shorter than the funicle in other species (Figures 3 B–I).
There is a high variability in color pattern in this species. All specimens previously examined by Voss (1943), Bondar (1950) and Vaurie (1954) have an entirely orange pronotum or the disk orange with sides yellow (Figure 10H). Viana (1975) reported specimens with two brown spots in the pronotum, some of them with rows of dark brown scales along the even intervals in the elytra (Figure 10J). I have observed these four color patterns in the specimens studied. There are, however, new patterns still unreported in the literature and rare in collections. Four individuals from Paraguay deposited in the NHMUK (Figure 10K) show a color pattern very similar to some of the morphs of Anchylorhynchus tremolerasi (Figure 12L). However, in A. bicolor the dark scales are dark brown instead of black, the females have larger scales near the procoxae and the antennal club is as large as the funicle, clearly identifying them as A. bicolor. Gottsberger & Silberbauer-Gottsberger (2006) present an image of Butia paraguayensis (Barb. Rodr.) L. H. Bayley from Brazil with several individuals of Anchylorhynchus resting in a spathe. Most of them represent the previously known color morphs for A. bicolor, but one individual has a color pattern similar to that shown in Figure 10K.
Geographical Distribution. This species occurs in savannas (cerrado) and grasslands in Brazil, Paraguay, Uruguay and Argentina (Figure 24).
Host Plants. Butia paraguayensis (Barb. Rodr.) L. H. Bailey
Likely Butia purpuracens Glassman Unlikely Butia capitata (Mart.) Becc. and Butia yatay (Mart.) Becc.
Species of Butia have a complex taxonomic history with unstable species concepts, rendering a list of host records based on labels difficult for A. bicolor. Bondar (1950) sampled from Cocos leiospatha Barb. Rodr. in Pirassununga, São Paulo, Brazil and specimens collected by I. Gottsberger from Botucatu, São Paulo, Brazil were labelled as sampled from Butia leiospatha (Barb. Rodr.) Becc. The latter is currently considered a junior synonym of Butia capitata (Mart.) Becc., but considering the geographical distribution (Lorenzi et al. 2010) these sampling events were most likely done in the species currently recognized as Butia paraguayensis (Barb. Rodr.) L. H. Bailey. This was the name used in a recent in publication using these specimens (Silberbauer-Gottsberger et al. 2013). Vaurie examined eight specimens from San Estanislao, Paraguay, claiming that they were collected from Butia yatay (Mart.) Becc. We examined three of these specimens, but there was no label indicating host plant. Considering that Butia paraguayensis (Barb. Rodr.) L. H. Bailey has been considered a subspecies of Butia yatay (Mart.) Becc. in the past, once again the most likely host plant is Butia paraguayensis considering the geographical distribution (Lorenzi et al. 2010). We have sampled A. bicolor from flowers of this plant species in Jardim, Mato Grosso do Sul, Brazil. Two specimens deposited in DEI and erroneously identified by Voss (1943) as A. parcus were collected in Jataí, Goiás, Brazil. The only species of Butia recorded in the area is Butia purpuracens Glassman. Even though there is no host record associated with these specimens, this is likely the host plant in the region.
Examined Specimens. Type Material. BRAZIL. São Paulo: Pirassununga, O. Schubart, X/1949 (♂ lectotype Anchylorhynchus leiospathae FMNH); 01/X/1949 (1♀ paralectotype Anchylorhynchus leiospathae AMNH).
PARAGUAY. No region: No locality, no collector, no date (♂ lectotype Anchylorhynchus parcus bicolor DEI, 1♀, 1♂, 1 sex undetermined paralectotypes Anchylorhynchus parcus bicolor DEI).
Other Material. ARGENTINA. Corrientes: No locality, M. J. Viana, X/1947 (4 sex undetermined MLPA); XI/1945 (4 sex undetermined MLPA). Misiones: No locality, Breyer, no date (1 sex undetermined MACN).
BRAZIL. Goiás: Jataí, no collector, no date (2♂ DEI); Pujol, no date (1♀, 1♂ NHMUK). Mato Grosso do Sul: Bonito, E. Trajano, 15/X/1990 (1♂ MZSP); Jardim, B. A. S. Medeiros & E. P. Antunes, 03/XII/2014 (7 sex undetermined MZSP). Paraná: Campo Mourão, no collector, I/1952 (2♀, 1♂ DZUP). São Paulo: Botucatu, Ilse Gottsberger, 03/ VII /1970 (1♀ MZSP); 04/IX/1970 (4♀, 4♂ MZSP); 07/VIII/1970 (1♀ MZSP); 08/I/1971 (1♂ MZSP); 18/IX/1970 (3♀, 1♂ MZSP); 23/ VII /1970 (1♀, 3♂ MZSP); Pirassununga, Emas, collector illegible, 28/ X/1949 (1♂ MZSP).
PARAGUAY. Cordillera: Altos, no collector, I/1914 (1 sex undetermined MACN). San Pedro: San Estanislao [San Estanislao de Kostka], Bridarolli, 21/I/1945 (2♀, 1♂ AMNH). Paraguarí: Sapucay [Sapucai], G. A. K. Marshall coll., 1950 (3♀, 1♂ NHMUK). No region: No locality, collector illegible, no date (1 sex undetermined MACN); no collector, no date (2♀, 1♂ DEI).
URUGUAY. Rivera: Sierra de la Aurora, C. S. Carbonell y L. C. de Zolessi, 15/I/1961 (1♂ MACN).
NO COUNTRY. No region: No locality, no collector, no date (5 sex undetermined MACN).
description: Published as part of De, Bruno A. S. & Vanin, Sergio A., 2020, Systematic revision and morphological phylogenetic analysis of Anchylorhynchus Schoenherr, 1836 (Coleoptera, Curculionidae: Derelomini), pp. 1-98 in Zootaxa 4839 (1) on pages 24-26, DOI: 10.11646/zootaxa.4839.1.1, http://zenodo.org/record/4487967