Eurhoptus LeConte, 1876

Anderson, Robert S. & Caterino, Michael S., 2018, A revision of the genus Eurhoptus LeConte, 1876 (Curculionidae, Cryptorhynchinae) of America north of Mexico, ZooKeys 787, pp. 37-80 : 41-43

Eurhoptus LeConte, 1876

Eurhoptus LeConte, 1876: 245; Blatchley and Leng 1916: 496; Kissinger 1964: 64; Papp 1979: 163; O’Brien and Wibmer 1982: 136; Downie and Arnett 1996: 1581; Alonso-Zarazaga and Lyal 1999: 131; Salsbury 2000: 347; Anderson 2002: 765; Ciegler 2010: 166.

Europtus ; Fiedler 1940: 300 (error, in key).

Eurrhoptus Rye 1878: 93 (unjustified emendation).

Type species.

Eurhoptus pyriformis LeConte, 1876: 245 (by monotypy). Gender masculine.

Redescription

(U.S.A. species only). Small, convex, rounded, dull black or dark-brown. Body length (exclusive of head and rostrum) 1.8-3.2 mm, cuticle either largely bare, variously covered with short, fine to coarse, recurved seta-like scales, lacking other scales or variously clothed with dense approximate to imbricate flat scales in addition to recurved seta-like scales. Rostrum short, stout, flattened dorsally, about as long as prono tum or slightly less, scaly towards base, glabrous, finely punctured towards apex in female, more coarsely so in male; medially carinate or not. Eyes small, flat, oval, largely covered by slight post-ocular lobes when rostrum in repose. Head with frons scaly, not impressed. Antennae red-brown, funicle of 7 desmomeres, club small, oval. Pronotum about as wide as long, lateral margins rounded or straight; if straight, then margins tapered more or less evenly from base to apex with greatest width at base; if rounded, then apical portion constricted, tubulate with greatest width before base. Basal margin nearly straight, disc variously punctured, medially carinate, sulcate or evenly punctured; post-ocular lobes slight. Elytra robust, strongly rounded dorsally and laterally, striae distinct, of small to very large punctures; all elytral intervals evenly elevated, slightly rounded, each with single row of recurved seta-like scales. Scutellar shield not visible. Mesoventral cup distinct, metaventrite short, medially impressed behind cup or carinate. Abdomen with ventrite 1 variously modified with large median or paired rather deep pits, pit either glabrous, shining or filled with erect scales; areas around pit often with dense, fine golden setae encircling depression; ventrite 5 broadly triangular, about as long as ventrites 2-4 combined. Legs with femora not toothed, narrow to stout (greatly so in some species where width accentuated by dense, erect scales along dorsal and lateral margins); tibiae narrow to stout (greatly so in some species where width accentuated by dense, erect scales along dorsal and lateral margins); tarsi fine, narrow, article 3 widest, bilobed; tarsal claws minute. Male with aedeagus short, one-half or less length of aedeagal apodemes, in lateral view very slightly curved ventrally to almost straight, in dorsal view with lateral margins subparallel, slightly to abruptly convergent towards apex at about apical one-third to one-fifth. Internal sac with apical sclerite complex of modified cruciform arrangement. Female with bursa copulatrix and vagina lacking any internal sclerotization, spermatheca L-shaped; distal gonocoxite elongate-triangular, with distinct long, slender apical stylus, sternite 8 with apical lamellae short, basally widely divergent, basal apodeme rather robust, elongate, expanded slightly at apex, tergite 8 tapered towards truncate or acuminate finely irregularly serrate apex.

Diversity.

For many years two species have been recorded as occurring in the eastern U.S.A., E. pyriformis and E. sordidus ; however, specimens from central Texas of E. sordidus differed in the structure of ventrite 1 with two separate impressions and not a single larger impression thus suggesting a third species was present. This species and two additional undescribed species were noted by Anderson (2002).

Natural history.

Almost all records of specimens of Eurhoptus are from sifting leaf litter in various forested habitats. Otherwise, nothing is known of life history and immature stages.