Minyomerus languidus [JF2015] Horn, 1876 sec. Jansen & Franz (2015)

Jansen, M. Andrew & Franz, Nico M., 2015, Phylogenetic revision of Minyomerus Horn, 1876 sec. Jansen & Franz, 2015 (Coleoptera, Curculionidae) using taxonomic concept annotations and alignments, ZooKeys 528, pp. 1-133 : 31-33

Taxon classification Animalia Coleoptera Curculionidae

Minyomerus languidus [JF2015] Horn, 1876 sec. Jansen & Franz (2015) Figs 16, 17, 18

== (INT) AND> (OST) Minyomerus languidus Horn, 1876: 18 sec. Horn (1876)

== (INT) AND> (OST) AND = Pseudelissa cinerea Casey, 1888: 274 sec. Casey (1888) (synonymized by Pierce 1909: 359)

Diagnosis.

Minyomerus languidus [JF2015] is most readily discerned from other congenerics by a combination of characters. The elytral setae are very uniform, linear, sub-recumbent, and brown, never with interspersed, longer, white setae. The elytral striae are often well defined and impressed, occasionally with punctures evident. The anterior margin of the pronotum has a reduced tuft of ocular vibrissae and is lined with linear setae that are inserted as far as 1/2 their length from the anterior margin. The nasal plate is bounded by a broad, somewhat weakly impressed sulcus. Importantly, the lateral margins of the oral cavity are strongly rounded, never straight, and longer than the posterior margin. Furthermore, the spermatheca has the ramus unconstricted and slightly bulbous.

Redescription - female.

Habitus. Length 3.28-3.91 mm, width 1.33-1.63 mm, length/width ratio 2.39-2.56, widest at anterior 1/3 of elytra. Integument orange-brown to black. Scales with variously interspersed colors ranging from slightly off-white to manila/tan to dark coffee brown, in some specimens appearing semi-translucent (in others opaque). Setae sub-recumbent.

Mandibles. Covered opalescent scales, with 2 longer setae, and 1 shorter seta between these.

Maxillae. Cardo bifurcate at base with an inner angle of ca. 100°, inner (mesal) arm 2 × longer than outer arm, inner arm of equal width to outer arm, inner arm of bifurcation equal in length to apically outcurved arm, glabrous. Stipes sub-quadrate, 1.5-2 × longer than wide, roughly equal in length to inner arm of bifurcation of cardo, glabrous. Galeo-lacinial complex apically incurved (mesally); setose in basal 1/2; dorsally with 6 apicomesal lacinial teeth; ventrally with 3 reduced lacinial teeth. Palpiger with a transverse row of 3 setae, sclerotized on basal 2/3.

Maxillary palps. Palpomeres I and II both apically oblique, forming a 45° angle with base, I and II each with 2 apical setae.

Labium. Prementum roughly pentagonal; apical margins sinuate, strongly angulate; lateral margins incurved; basal margin arcuate. Labial palps 3-segmented, I with apical 1/2 projecting beyond margin of prementum, reaching apex of ligula; III slightly longer than II.

Rostrum. Length 0.50-0.64 mm, anterior portion 1.5-2 × broader than long, rostrum/pronotum length ratio 0.63-0.72, rostrum length/width ratio 1.37-1.43. Dorsal outline of rostrum sub-rectangular, anterior half of dorsal surface strongly impressed, posterior half strongly rugose. Rostrum in lateral view rectangular; apical margin with 2 large vibrissae. Nasal plate strongly defined by Y-shaped, impressed lines, convex, covered wth whitish scales. Margins of mandibular incision directed 30° outward dorsally in frontal view; ventrolateral sulci usually defined, beginning as a sulcus dorsad of insertion point of mandibles, running parallel to scrobe, becoming fainter posteriorly and disappearing ventrally. Dorsal surface of rostrum with median sulcus running from fovea at posterior end of anterior half rostrum to midpoint of posterior half of rostrum. Rostrum ventrally lacking foveae in line with insertion point of mandibles. Oral cavity with lateral margins strongly curved.

Antennae. Dorsal margin of scrobe overhangs slightly (broadly, not forming a sharp tooth) ventrad of anterior margin of eye. Scape just extending to posterior 1/2 of eye. Funicular antennomeres evenly progressing from elongate to broader than long; terminal segment of equal length but wider than preceding segment and lacking appressed scales, having instead a covering of apically-directed pubescence with interspersed sub-erect setae. Club nearly 2.5 × as long as wide, with setation and pubescence as in final segment of funicle.

Head. Eyes separated in dorsal view by 4-5 × their anterior-posterior length, touching anterior prothoracic margin.

Pronotum. Length/width ratio 0.80-0.93, sub-cylindrical to conical; widest near anterior 1/4. Anterior margin arcuate, lateral margins feebly curved and widening into a slight bulge just past anterior 1/4 of pronotum, thence straight to posterior margin, posterior margin straight. Pronotum in lateral view with setae that reach beyond anterior margin; these setae becoming evenly longer laterally, reaching into anterior 1/2 of eye at their maximum length. Anterolateral margin with a reduced tuft of post-ocular vibrissae present, consisting of 5-7 setae, emerging near dorsal 1/2 of eye, becoming gradually, evenly longer ventrally, stopping just beneath ventral margin of eye; vibrissae achieving a maximum length 1/2-3/5 × anterior-posterior length of eye.

Scutellum. Hidden in some specimens, narrowly exposed in others (visible area approximately equal to length of appressed scales), margins straight.

Pleurites. Metepisternum covered by elytron near posterior 1/5 of metasternum.

Thoracic sterna. Mesocoxal cavities separated by distance 1/3-1/2 × width of mesocoxal cavity. Metasternum without apprent transverse sulcus; metacoxal cavities widely separated by 4-5 × their width.

Legs. Profemur/pronotum length ratio 0.93-1.03; distal 1/5 of profemur produced ventrally as a nearly semicircular projection covering tibial joint. Protibia/profemur length ratio 0.84-0.93; mucro reduced to a very small laterally projected tooth. Protarsus with tarsomere III equilateral. Metatibial apex with almond shaped convex ity ringed by 8 short, widely separated, spiniform setae.

Elytra. Length/width ratio 2.94-3.46; widest at anterior 1/3; anterior margins jointly 1.5-2 × wider than posterior margin of pronotum; lateral margins sub-parallel after anterior 1/4, more strongly rounded and converging in posterior 1/2. Elytra sculpted with a depression at anterior 1/3; posterior declivity angled at nearly 70° to main body axis. Punctures visible, deep and distinct in some specimens, separated by 3-4 × their diameter.

Abdominal sterna. Ventrite III elevated and set off from IV along lateral 1/4s of its length. Sternum VII mesally 3/5 × as long as wide; setae darker, longer, and becoming more erect and setiform in mesal 1/2 of posterior 2/5; anterior margin weakly curved.

Tergum. Pygidium sub-conical; medial 1/3 of anterior 2/3 of pygidium less sclerotized, with a patch of very short, fine setae.

Sternum VIII. Anterior laminar edges of spiculum ventrale each incurved forming a 100° angle with lateral margin; lamina more sclerotized medially.

Ovipositor. Coxites in dorsal view 2 × as long as broad; styli 3/4 × length of coxites, with 4 long setae near base.

Spermatheca. Comma-shaped; collum short, apically with hood-shaped projection sub-parallel to ramus, 2/3 × length of ramus and contiously aligned with curvature of bulb of ramus; collum sub-contiguous with, and angled at 90° to ramus; ramus bulbous, slightly larger than collum; corpus not swollen, of equal thickness to collum and cornu; cornu elongate, apically gradually narrowed, strongly recurved in basal 1/4, gently curved along mesal 1/2, and curved and somewhat flattened near apical 1/4 such that apex is sub-parallel to hood-shaped projection of collum.

Male.

Not available or known.

Material examined.

Holotype (for Minyomerus languidus sec. Horn [1876]) - female (only images seen: MCZ Type Database) "Cal/ Type No. 2800 [old ANSP number, red]/ Horn Coll H 8231/ Minyomerus languidus Horn/ MCZ TYPE 286 [red]" (MCZ); holotype (for Pseudelissa cinerea sec. Casey [1888]; junior synonym) "●Tex [Casey locality code: El Paso including both banks of the Riv. Grande which is here about 100 ft. in width]/ Casey bequest 1925/ Type USNM 35007 [red]/ Pseudelissa cinerea Cas" (USNM: 1 female). Additional specimens examined: "PORTAL, Ariz, 1 mi. E. i 6-VII-59, D.G. Kissinger, Acc. No. 510/ Minyomerus languidus , Horn, det. D.G. Kissinger" (CSCA: 5 females); "TEX. Briscoe Co. 27 mi. NE. Silverton, Hwy 70, V-14-1970/ Collector: C.W. O’Brien” (CWOB: 8 females) [4 females deposited at CMNC]; "AZ. Cochise Co, Hwy 186, 3 mi SE. Wilcox, on Blue Sky Road, 4200', Sept. 5, 2007/ sand dunes, LB. & C.W. O’Brien, on Atriplex [non-focal]" (CWOB: 3 females); "Ariz. 7 mi. S. Pearce 4150, Cochise Co., IX-7-1965/ on Astera[c]ea[e?] [non-focal], C.W. O’Brien” (CWOB: 4 females); "Tex. Pine Springs, Culberson Co., night 8-18-1970, C.W. O’Brien” (CWOB: 4 females); "Tex. Pine Springs, Culberson Co., night 8-18-1970, L.B. O’Brien” (CWOB: 13 females) [6 females deposited at CMNC]; "Socorro Co. NM, Sevilleta NWR, LTER Site 6, 11 Mar 1992/ 34 [series ID]" (CWOB: 1 female); "Socorro Co. NM, Sevilleta NWR, LTER Site 6, 27 May 1992/ 42 [series ID, part of series including 42, 43, 45, and 46]" (CWOB: 4 females).

Distribution.

This species has been found in the desert and arid regions of east-central California, Nevada, Arizona, New Mexico, Texas (USA); O’Brien and Wibmer (1982: 46) also have Baja California listed, but this might be a result of a misidentification and confusion with Minyomerus gravivultus [JF2015]. It is likely that its range also includes northern Chihuahua, Coahuila, and Sonora (Mexico), based on similarity in habitat to the currently known distribution (Fig. 51).

Natural history.

Associated with creosote bush ( Larrea tridentata [DC.] Coville [non-focal]; Zygophyllaceae [non-focal]), broomweed ( Gutierrezia [non-focal] sp.; Asteraceae [non-focal]), and saltbush ( Atriplex [non-focal] sp.; Amaranthaceae [non-focal]). This species is putatively considered parthenogenetic given the lack of male specimens across a range of sampling events.