Anchylorhynchus burmeisteri Faust, 1894

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 : 28-29

Anchylorhynchus burmeisteri Faust, 1894

( Figures 2F , 8G , 11 A–B, 16B, 18A, 21G)

Anchylorhynchus burmeisteri Faust, 1894: 152 (description); Blackwelder, 1947:827 (cat.); Vaurie, 1954:30, Fig. 3F (revision); Viana, 1975:16, Fig. 11 (revision); Wibmer & O’Brien, 1986:195 (cat.). Lectotype (designated here): Male; Entre Rios, Argentina; Berg col.; collection J. Faust. Deposited in MTD, images examined.

Anchylorhynchus burmeisteri var. bimaculatus Faust, 1894: 152 (description); Blackwelder, 1947:827; (cat.) Vaurie, 1954:30 (revision, synonymy to Anchylorhynchus burmeisteri ). Holotype: Male; Entre Rios, Argentina; Berg col; collection J. Faust. Deposited in MTD, images examined.

Ancylorrhynchus burmeisteri ; Voss, 1943:63 (revision); Bondar, 1943a:361 (revision).

Redescription. Male: Body size (length of elytra + pronotum) 7.6–8.6 mm.

Head: Rostrum 1.3–1.4 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), distinct throughout their length; scrobes parallel to rostrum; apex covered by microsetae; areas between dorsal carinae covered by yellowish scales, narrow to setiform at base and setiform at the apex, directed toward the central carina. Eyes 1.3–1.5 times as high as wide; 0.9–1.0 times more separated above than below. Head with integument brown to black, similar to or lighter than rostrum; entirely covered by yellow scales directed to the base of rostrum. Antennae with scape straight, barely reaching anterior eye margin; funicle: antennomere I of funicle only slightly wider than II, II about as long as I and about 1.5 times as long as III, VI as wide as long and narrower than club; club about as long as antennomeres V–VI of funicle. Left mandible strongly sinuate at outer margin; with one dorsal seta; outer tooth not forming a sharp angle, with somewhat blunt apex; inner tooth well-developed; molar region slightly concave. 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 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 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; ligula present but inconspicuous; palps separated by less than 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 1.6–1.7 times pronotum length; base slightly lobed at middle; lateral margins in dorsal view strongly convergent from base to apex, with an inflexion in the median region, with a subtle apical constriction; integument uniformly brown to black; covered by yellowish scales on most of its area and black scales on lateral-apical region; scales on disk with basal half directed to the base. Profemur approximately 3 times as long as wide; dorsal margin with curvature less pronounced than 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 0.7–1.0 times longer than wide; integument brown to black, usually darker than elytra; scales yellowish on the sides and brown to black in the middle. Elytra 1.3–1.5 times wider than pronotum; 1.5–1.6 times longer than wide; 3.4–3.7 times longer than pronotum; humeri rounded; lateral margins subparallel, only slightly wider at middle; with uniformly yellow scales, or with round spots of black scales next to the epipleura and yellow scales elsewhere; epipleura without a marked inflexion on interval IX, covered by dark scales. Ventral region of thorax integument brown to black; scales black in the proepisternum and mesepimeron and elsewhere yellowish to white, lighter than those in pronotum disk. Hypomeron covered by sparse scales with truncated apex larger and wider than those in pronotum; scales next to coxal cavities larger. Prosternum length 0.8–0.9 times the width of coxae; postocular lobes indistinct, with apical-lateral margin of prothorax regularly curved to slightly sinuate; covered by overlapping scales with truncated apex, narrower than those in pronotum. Metepisternum entirely covered by overlapping scales. Metasternum central concavity distinct; covered by scales in the center.

Abdomen: Ventrites III–V covered by narrow recumbent scales and erect setae. Aedeagus 2–2.5 times as long as wide; about 5 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 2 times as long as aedeagus. Endophallus membranous and slightly sclerotized in area anterior to the basal sclerite and with one pair of membranous pockets containing microtrichae next to the basal sclerite; microtrichae of the apical region not organized in bands.

Female: Body size 8.3–9.3 mm. Rostrum 1.3–1.4 times longer than pronotum; width at apex 1.2–1.4 times width at base. Eyes 1.5–1.5 times as high as wide; 0.8–0.9 times more separated above than below. Pronotum 1.6–1.7 times as wide at base as long. Prosternum length 0.8–0.9 times the coxal width. Scutellum 0.7–0.9 times as long as wide. Elytra 1.4 times as wide as pronotum1.5–1.5 times as long as wide; 3.5–3.6 times as long as pronotum. Ventrites III–V with recumbent narrow scales. Ventrites III and IV with posterior retraction slightly sinuate and reaching the middle of the segment.

Remarks. Together with A. vanini , this is one of the largest species of Anchylorhynchus (more than 7.6 mm pronotum + elytra). In addition to the size, it has a number of distinctive characters: scales of the head directed toward the rostrum ( Figure 2F ), profemora with dorsal margin only slightly arcuate ( Figure 18A ), scutellum with both black and yellow scales ( Figure 11 A–B), male ventrites with both recumbent scales and erect hairs, pronotum with scales directed to the base until the median region and with an inflexion in the lateral margins ( Figure 8G ). The color patterns with ( Figure 11B ) and without ( Figure 11A ) a dark spot of black scales in the elytra are sympatric.

Faust described A. burmeisteri from at least five syntypes, one of them currently deposited in the USNM and the others deposited in the MTD. These syntypes have not been examined in previous revisions of the genus, so a lectotype for A. burmeisteri remains to be designated. Both male syntypes in the MTD lack middle legs and females appear to be intact. Despite this small damage, it is safer to have a male as lectotype as very closely related species can be more easily distinguished by male genitalia and secondary sexual characters. Here we designate one of the male specimens in the MTD as the lectotype, rendering the rest of the type series paralectotypes. Even though we have not visited MTD, the collection manager Olaf Jäger has provided images and labelled specimens accordingly.

Geographical Distribution. This species occurs in grasslands in Argentina, Uruguay and also likely in southern Brazil, where its host plant occurs ( Figure 24 ).

Host Plants. Butia yatay (Mart.) Becc.

The type series studied by Faust (1894) was reared from an unidentified palm. Viana (1975) collected specimens from Butia yatay in Entre Rios, Argentina, and we also sampled A. burmeisteri from this palm in the same area.

Examined Specimens. Type Material. ARGENTINA. Entre Rios: No locality, Berg , date illegible (♂ lectotype Anchylorhynchus burmeisteri MTD , 2♀, 1♂ paralectotypes Anchylorhynchus burmeisteri MTD ); no collector, no date (1♂ paralectotype Anchylorhynchus burmeisteri USNM ); Berg, date illegible (♂ holotype Anchylorhynchus burmeisteri var. bimaculatus MTD ) .

Other Material. ARGENTINA. Corrientes: No locality, C. Bruch, no date (1♂ MACN) . Entre Rios: Concordia , Caguerre, no date (3♀, 2♂ MACN) ; collector illegible, 11/I/1979 (1♂ MACN) ; No locality, M. J. Viana, XII/1946 (1♀ MLPA) ; Primero de Mayo , L. Gontero, I/1960 (4 sex undetermined MACN) ; Ubajay, Refúgio de Vida Silvestre La Aurora del Palmar , B. A. S. Medeiros, 28/I/2010 (5♀ MZSP) ; 29/I/2010 (3♀, 6♂ MZSP) ; Villa Elisa , no collector, no date (1 sex undetermined MACN) .

URUGUAY. Paysandú: Paysandú , CSC-MAM-PRSM, 16/XII/1966 (5♀, 9♂ MACN) .

NO COUNTRY. No region : No locality, no collector, no date (2♂ MACN) .

Figures

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 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 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 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.