Lissorhoptrus LeConte, 1876

O'Brien, Charles W. & Haseeb, Muhammad, 2014, Revision of the “ Rice Water Weevil ” Genus Lissorhoptrus LeConte (Coleoptera: Curculionidae) in North America North of Mexico, The Coleopterists Bulletin 68 (2), pp. 163-186 : 165

Lissorhoptrus LeConte, 1876

Lissorhoptrus LeConte 1876: 183 . Type species: Bagous simplex Say 1832 , by subsequent designation (Kuschel 1952: 28); original designation (LeConte 1876: 183) based on misidentification. Gender masculine. Champion (1902); Kolbe (1911); Blatchley and Leng (1916); Hustache (1926); Tanner (1943); Kuschel (1952); Kissinger (1964); O’ Brien and Wibmer (1982); Wibmer and O’ Brien (1986, 1989); Alonso-Zarazaga and Lyal (1999); Anderson (2002).

Redescription. Small to large (length 2.00– 4.20 mm), moderately stout to slender, elongateoval; cuticle reddish brown to black; dorsum and much of venter densely clothed with imbricate scales and waterproof coating. Rostrum: Moderately long (shorter than prothorax), thick, nearly straight, dorsum weakly curved (rarely gibbous basally), venter straight; dorsal surface and occasionally lateral surfaces with waterproof coating, dorsum toward apex with hydrofuge scales; scrobe short, directed ventrally, dorsal margin usually evident in lateral view; suprascrobal groove narrow to broad, often partly concealed by waterproof coating, clothed with dense hydrofuge scales. Antennae: Inserted ca. 1/4 − 2/5 from apex of rostrum; scape not reaching eye, with 1 coarse seta (often abraded); 6 funicular antennomeres; club elongate, narrow, usually strongly asymmetrical, basal antennomere usually glabrous (tomentose in Lissorhoptrus panamensis (Champion) , much more than 0.50X length of club. Head: Weakly to moderately convex; frons usually subequal in width to rostrum at apex, rarely narrower or wider; eyes moderately to weakly convex, lateroventral or lateral. Pronotum: Strongly transverse; with few, relatively inconspicuous, marginal setae; punctures concealed by scales and waterproof coating; postocular lobes usually strong. Scutellum: Not visible. Elytra: Humeri oblique, well-developed to very weakly developed; sides subparallel to declivity, then suddenly strongly narrowed to conjointly rounded, subquadrate, or subacutely emarginate apices; sutural interval not depressed; intervals flat to convex, none more elevated, odd-numbered with inconspicuous to conspicuous, moderately short, coarse to fine, curled, erect to suberect setae; striae with enlarged foveae; macropterous. Venter: Prosternum not medially sulcate, lacking ridge or elevation in front of fore coxa; scales of prosternum, part of mesosternum, coxae, and abdominal ventrites III–V hydrofuge; mesepimeron normal, lacking anteriorly projecting tubercle; abdominal ventrites I–II not vaulted, moderately convex, but not on same level as ventrites III–V. Legs: Moderately stout; fore coxae contiguous, not strongly elongate, middle coxae narrowly separated; femora and outer surface of tibiae clothed with dense agglutinate scales, inner surface of tibiae clothed with coarse setae and dense hydrofuge scales; outer margin of apex of tibiae rounded to subquadrate, lacking denticle, inner margin not denticulate; fore tibiae with strong uncus and premucro, other tibiae mucronate and with premucro; middle tibiae blade-like, with evenly strongly curved outer margin, with dense, elongate swimming hairs (or rarely short swimming bristles) on inner and outer margins for entire length; male hind tibia with apical mucro modified with variously shaped and sized tubercles or teeth, female with simple hook and premucro unmodified on all legs; tarsi moderately short, tarsomeres together not as long as tibia, with ventral to lateral, mediumlength hairs, linear to sublinear, tarsomere 3 truncate to cordate and feebly emarginate, tarsomere 4 not visible in lateral view, claw tarsomere clearly extending beyond tarsomere 3, lacking long, curled, apical seta and lacking pad or scale between long, fine approximate tarsal claws. Male: Median lobe ( Figs. 31–34 ) lacking flagellum; apodemes much longer than median lobe, inserted between 1/3 from base and near middle of median lobe; median lobe moderately flat, dorsal plate indistinct, ventral plate little narrowing behind apodemal insertions; membranous sac short to medium-sized, far from reaching tips of apodemes, with large apical plate, and spicules throughout length; tegmen closed apically, with 2 very long, inwardly directed processes fused to sides of ring; spiculum gastrale with arms usually somewhat at angle with apodeme in lateral view (spiculum rarely rather evenly, strongly curved), apodeme expanded laterally at base, arms medium to long, fused apically, with moderately narrow, thin (almost transparent), lateral “wings”; sternite X divided into 2 plates; tergite VII lacking anteriorly directed processes, apical margin with broad liplike edge. Female: Sternite VIII with apodeme not bifurcate, free portion somewhat shorter than blade; spermatheca with cuticle nonreticulate; ramus scarcely distinct, arising far from nodulus; spermathecal duct very short, moderately broad, flexible, attached at apex of bursa copulatrix; bursa not constricted at base; coxite flattened (blade-like); stylus lacking; apex of tergite VI moderately emarginate, margin somewhat irregular; apex of tergite VII rounded or slightly produced medially, margin smooth with blade-like edge.

Figures

Figs. 31–34. Lissorhoptrus species, male median lobe, dorsal view. 31) L. simplex; 32) L. oryzophilus; 33) L. lacustris; 34) L. robbinsorum.