Acoptus LeConte, 1876: 264

Anzaldo, Salvatore S., 2017, Review of the genera of Conoderinae (Coleoptera, Curculionidae) from North America, Central America, and the Caribbean, ZooKeys 683, pp. 51-138 : 68

Acoptus LeConte, 1876: 264 Figs 5 , 24 , 42 , 73

= Homogaster Provancher, 1877: 530 [Syn.: Blackwelder and Blackwelder 1948: 48]. Type species: Homogaster quebecensis Provancher, 1877 [by monotypy].

Type species.

Acoptus suturalis LeConte, 1876 [by monotypy].

Gender.

Masculine.

Diagnosis.

Acoptus can be easily recognized from the rest of the conoderines treated here by the following characteristics: the inner margin of eyes towards the top has a large lanceolate space (Fig. 42 ) and the eyes are nearly touching above and below the lanceolate space, the mandibles are somewhat falcate and are in contact only at the apex (visible in Fig. 5 ), and the tibial apex distally has the dorsal margin dilated and premucro absent from all tibiae (Fig. 24 ). The relatively forward facing eyes that do not extend much on lateral portions of head (genae large), the first funicular article that is longer than the second, the unmodified mesoventrite, the ventrally toothed and non-carinate metafemora, the unarmed femoral apices, the small and non-ascending mesopleura, the absent sclerolepidia, and the abdominal ventrites that are not rapidly ascending additionally help diagnose the genus and in combination separate it from all Lechriopini and other New World Conoderinae .

Notes.

The species Homogaster quebecensis was first placed in synonymy with Piazurus subfasciatus LeConte, 1876 (= Lechriops subfasciatus (LeConte)) by LeConte (1880: xii), where it remained in catalogs until Blackwelder and Blackwelder (1948: 48) listed it in synonymy with Acoptus suturalis . Provancher’s description agrees with that of Acoptus .

Phylogenetic relationships.

In keys to North American genera, Acoptus is always separated from the rest of the North American genera along with Psomus by the flat abdominal ventrites (e.g. Hespenheide 2002: 755). Casey (1892: 458, 1897: 666) suggested a relationship to Psomus on these grounds, but this similarity only suggests they are both aberrant in their placement in the Lechriopini - they are otherwise very different in appearance, as also noted by Casey (1892: 458). LeConte (1876: 264) originally distinguished his genus from Copturus (which, with the geographic scope and time of publication of the key included only species currently placed in Cylindrocopturus and Eulechriops ) and Zygops by the nearly flat abdominal ventrites and elongate first funicular article. Provancher (1877: 530), apparently independently, separated his genus Homogaster from Zygops and Copturus (as well as the South American Timorus ) for the same reasons. A phylogeny by Davis (2014) recovered Acoptus as closer to the Old World genus Mecopus ( Conoderinae : Mecopini ) than any of the included New World conoderines, a result consistent with the new placement of the genus (the study did not include Othippiini ).

Host associations.

Mentions in the literature of host plants include Fagus L. ( Fagaceae Dumort) ( Chittenden 1890: 171), Ulmus americana L. ( Ulmaceae Mirb.) ( Hoffman 1942: 12) and Juglans cinerea L. ( Juglandaceae DC. ex Perleb) ( Halik and Bergdahl 2002). Sleeper (1963: 215) additionally reports Quercus L. ( Fagaceae ), Cercis canadensis L. ( Fabaceae Lindl.), Carya Nutt. ( Juglandaceae ), and Platanus occidentalis L. ( Platanaceae T. Lestib.). Adults of A. suturalis have been implicated as vectors of the chestnut blight fungus, Cryphonectria parasitica (Murrill) Barr ( Pakaluk and Anagnostakis 1977) and the butternut canker fungus, Sirococcus clavigignenti-juglandacearum Nair, Kostichka & Kuntz ( Halik and Bergdahl 2002).

Described species.

One.

Range.

Eastern Canada, Eastern U.S.A., extreme northeastern Mexico ( Sleeper 1963: 215). Specimens have not been observed from Mexico or even Texas to confirm Sleeper’s range extension; recently the genus was reported for the first time from Arkansas ( Skvarla et al. 2015).

Figures

Figures 1 - 9. Variation in the mesoventrite. 1 Trichodocerus brevilineatus [ARTSYS 0000616] showing a prosternal rostral " sheath " with the sides converging below the procoxae, the transverse ridge anterior to the mesocoxae and the region of the mesoventrite posterior to the ridge with dense yellow scales 2 Lobops bonvouloiri [ARTSYS 0000527] showing a cup-shaped receptacle for receiving the rostrum 3 Piazurus trifoveatus [SSAC 0001118] with an " open " channel on the mesoventrite 4 Pseudopinarus condyliatus [SSAC 0001116] with an " open " channel on the mesoventrite 5 Acoptus suturalis [ASUHIC 0016914] showing a flat, unmodified mesoventrite 6 Copturus sanguinicollis [ASUHIC 0086638] showing a closed receptacle on the mesoventrite with lateral flanges 7 Cylindrocopturinus pictus [SSAC 0001288] showing a rostral channel of the mesoventrite formed by relatively parallel carinae and no posterior termination 8 Euzurus ornativentris [ARTSYS 0000796] 9 Hoplocopturus javeti [SSAC 0001289] with an inverted U-shaped carina and the region posterior to the carina invaginated.

Figures 19 - 36. Variation in the metatibial apex. 19 Mesotibial apex of Lechriops vestitus illustrating parts of the tibial apex: a) posterior apical angle with large, curved uncus; b) middle of the apex with produced, rounded inner flange; c) anterior apical margin with premucro; d) oblique ridge of premucro; e) apical setal tuft 20 Male Trichodocerus brevilineatus [ARTSYS 0000609] with a tibial uncus arising at the middle of the apex 21 Cratosomus punctulatus mexicanus [ASUHIC 0031510] with thick fascicles of golden setae near the anterior apical margin and a dense setal brush at the posterior apical face 22 Pseudopiazurus centraliamericanus [ASUHIC 0086627] with a large, subapical premucro 23 Piazurus laetus [SSAC 0001077], showing a typical tibial apex for that genus 24 Acoptus suturalis [ASUHIC 0016915] 25 Cylindrocopturinus pictus [SSAC 0001288] with a pointed, premucro-like inner flange 26 Pseudolechriops klopferi [SSAC 0001060] showing an elongate, uncus-like inner flange. 27 Arachnomorpha circumlineata [ARTSYS 0000535] 28 Archocopturus medeterae [ASUHIC 16884] 29 Cylindrocopturus adspersus [ASUHIC 0016896] with a rounded, produced inner flange 30 Helleriella longicollis [ASUHIC 0065241] with a very short uncus 31 Lissoderes cecropiae [ASUHIC 0064707] with an elongate uncus and minute premucro 32 Phileas granulatus [ARTSYS 0000528] with the middle of the apex (between uncus and premucro) sunken 33 Peltophorus adustus [ASUHIC 0012325] with a short uncus and posterodistal setal comb extending halfway to the base of the tibia 34 Zygops erythropygus [ASUHIC 0086640] with short posterodistal setal comb. 35 Philenis flavipes [ASUHIC 0065102] 36 Philinna bicristata [ARTSYS 0000799] with a small tooth at the anterior apical angle.

Figures 37 - 45. Variation in eye shape. 37 Trichodocerus brevilineatus [ARTSYS 0000609] with large, subcontiguous eyes that continue below rostral insertion 38 Cratosomus punctulatus mexicanus [ASUHIC 0031510] with relatively small, widely separated eyes 39 Lobops bonvouloiri [ARTSYS 0000658] with widely separated eyes and the frons concave between the upper half of the eye 40 Pseudopiazurus centraliamericanus [ASUHIC 0086627] with very large eyes that are contiguous in upper half 41 Pseudopinarus guyanensis [ASUHIC 0086636] with large, subcontiguous eyes and an arcuate carina on the vertex of the head 42 Acoptus suturalis [ASUHIC 0016914] with subcontiguous eyes separated at the top by a lanceolate space 43 Cylindrocopturinus pictus [SSAC 0001288] 44 Macrocopturus lynceus [SSAC 0001085] with very large, partially contiguous eyes 45 Microzygops nigrofasciatus [ARTSYS 0000802] with large eyes contiguous in the bottom 2 / 3 and widely separated at the top.

Figures 71 - 74. Lateral and dorsal habitus images of Piazurini, Othippiini and Lechriopini. Scale bars = 2 mm unless otherwise specified 71 a-b Pseudopiazurus centraliamericanus [ASUHIC 0086627]; scale bars = 5 mm 72 a-b Pseudopinarus condyliatus [ASUHIC 0086626]; scale bar for 72 a = 1 mm 73 a-b Acoptus suturalis [ASUHIC 0016914] 74 a-b Copturomimus cinereus [ASUHIC 0086628].