Randersonia Chamorro, 2022

Chamorro, M. Lourdes & Presnall, Tara Milovana, 2022, Randersonia Chamorro, a new genus with two new species of North American Cryptorhynchinae (Coleoptera: Curculionidae), Zootaxa 5222 (6), pp. 591-599 : 592

Randersonia Chamorro gen. nov.

( Figs 1–3 )

http://zoobank.org/ urn:lsid:zoobank.org:act:5CD84C86-2426-4159-9B8E-7FBD4D433D0B

Gender. Feminine

Type species. Randersonia schwarzi Chamorro & Presnall new species, here designated.

Differential diagnosis. The new genus is similar to Paracamptus ( Fig. 4 ) based on the presence of the following characters: simple claws, sternal channel extended posterior to mesosternum, funicle with 7 articles, metasternum long with the distance between the middle and hind coxae subequal or longer than length of antennal club, pronotum produced over head, and tibia very short, less than one-half as long as femur and with large erect scales. Randersonia differs from Paracamptus and other Cryptorhynchinae based on the presence of the following features: integument light reddish-brown colored, mostly glabrous with scattered plumose and elongate spatulate, erect scales (in Paracamptus the integument is clothed in tightly arranged scales obscuring the underlying cuticle); interstriae flat, (elevated in Paracamptus ), metanepisternal suture covered by elytra; punctation large and deep (diameter less than distance between punctures); wings absent, humeri not prominent; and hind tibiae with comb of stout setae.

Description. Body elongate-narrow to oval, 1.25–1.50 mm in length (exclusive of head and rostrum), 0.5–0.8 mm in width (measured at widest point), depth 0.4 mm, color light reddish-brown, integument mostly glabrous with deep punctation throughout and sparsely placed erect, plumose and elongate spatulate scales. Head not impressed, with scattered scales variously arranged. Rostrum straight, moderately long, about as long as or longer than pronotum, with dorso-ventrally flattened, scales variously arranged, antennae inserted one half to one-third from base of rostrum. Mandibles triangular. Antennae light brown, funicle with seven desmomeres, club narrow, pilose, elongate. Eyes separated by about diameter of eye, oval, flat, not covered by post ocular lobes. Pronotum produced over the head, two times longer than wide, anterior margin medially feebly emarginate to evenly convex, lateral margins subparallel, widest point medially or basally, in lateral view pronotum sinuate one third from anterior margin; prominently, variously punctate; with two types of variously located scales (erect clavate and plumose); post-ocular lobes weakly evident along ventral margin. Elytra elongate cylindrical to subcylindrical, twice length of pronotum, lateral margins subparallel in basal two-thirds, moderately narrowing apically, humeri weakly to not developed; large, deep punctures aligned into longitudinal striae, interstriae flat, with interspersed light brown, elongate, clavate, erect scales; disk of elytra without fascia. Metasternum long, distance between middle and hind coxae longer than length of antennal club; metanepisternal suture concealed under elytra. Scutellum small or apparently absent. Venter either clothed or not clothed with clavate scales, crust sometimes evident, sparsely setose, feebly punctate; sternal channel rimmed, well developed, extended posterad, ending between middle coxae, punctation not well-developed, distance between middle and hind coxae distinctly longer than length of antennal club. Abdominal ventrites 1 and 2 subequal in length, appearing fused, together at least 1.5 times longer than 3–5 combined, 3 and 4 shorter than 5. Pygidium covered by apex of elytra. Legs with outer surface with scattered clavate, erect scales; femora elongate, narrow, unarmed; tibia short, half as long as femora, hooked spur and row of stout spine-like setae forming comb at apex. Tarsi subequal in length to tibiae, first and second tarsomeres twice wider than long, third tarsomere bilobed, fifth tarsomere subequal in length to first and second combined, tarsal claws simple and divergent, stout, each longer than tibial spur.

Etymology. The genus is named in honor of Robert “Bob” Anderson, friend, colleague, and mentor. Bob has offered constant and unwavering guidance to MLCh and his knowledge of all things weevil, enthusiasm, and all around good nature and humor has served as an inspiration.

Distribution. Virginia, USA and Tampico, Mexico.

Figures

FIGURE 1. Habitus of Randersonia cartwrighti Chamorro & Presnall, sp. n., male. A—lateral view; B—dorsal view; C— ventral view.

FIGURE 2. Habitus of Randersonia schwarzi Chamorro & Presnall, sp. n., male.A—lateral view; B—dorsal view; C—ventral view.

FIGURE 3. Median lobe of Randersonia schwarzi Chamorro & Presnall, sp. n. A—lateral view; B—dorsal view.

FIGURE 4. Habitus of Paracamptus floridanus Sleeper. A—lateral view; B—dorsal view; C—ventral view.