Minyomerus puticulatus [JF2015] Jansen & Franz 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 : 58-65

Taxon classification Animalia Coleoptera Curculionidae

Minyomerus puticulatus [JF2015] Jansen & Franz sec. Jansen & Franz (2015) sp. n. Figs 33, 34, 35

Diagnosis.

Minyomerus puticulatus [JF2015] is best distinguished from other congenerics by a combination of characters. The elytral striae are usually strongly punctate, with regu lar rows of brown setae on the intervals. The elytra appear somewhat flattened in lateral view, and do not project far above or below the pronotum. The pronotum has a reduced tuft of post-ocular vibrissae on the anterior margin. Additionally there is a row of setae that are inserted by approximately their own length from the anterior margin, and never less than 3/4 of their length. The margins of the oral cavity are nearly straight, and usually sub-parallel. The nasal plate is strongly impressed and well defined, and the frons is somewhat bulbous. The spermatheca is quite distinct, with the ramus basally tapered, and the corpus possessing an annulate, cylindrical projection nearly 2/3 × length of the ramus. The aedeagus is uniquely narrow and elongate, and bears a very minute apical flagellar sclerite.

Description - female.

Habitus. Length 3.37-4.19 mm, width 1.33-1.58 mm, length/width ratio 2.53-2.65, widest at anterior 1/3-2/5 of elytra. Integument dark reddish-brown to black. Scales slightly off-white to manila/tan to brown, in some specimens appearing semi-translucent (in others opaque). Setae minute, becoming longer on sides of pronotum and venter.

Mandibles. Covered with white to yellowish scales, with 4 longer setae, and 1-2 shorter interspersed setae.

Maxillae. Cardo bifurcate at base with an inner angle of ca. 100°, inner (mesal) arm 2 × longer and of equal thickness, inner arm of bifurcation equal in length to apically outcurved arm. Stipes nearly square, equilateral, roughly equal in length to inner arm of bifurcation of cardo, with 1 long lateral seta. Galeo-lacinial complexmembranous and setose in posterior 2/3, sclerotized and somewhat emarginate anteriorly; dorsally with 9 apicomesal lacinial teeth; ventrally with 3 reduced lacinial teeth. Palpiger with a transverse row of setae; anterior 1/5 membranous, posteriorly sclerotized.

Maxillary palps. Palpomere 1 with apical end facing mesally and forming a 45° angle with base, I and II each with 2 apical setae; II with 1 mesoventral seta in addition to 2 apical setae.

Labium. Prementum quadrangular, ventrally sub-planar throughout; apical margins nearly straight, angulate, lateral margins slightly incurved, posterior margin broadly curved. Labial palps 2-segmented, I with apical 1/3 projecting beyond margin of prementum, but not reaching apex of ligula; I with 1 apical seta; II slightly shorter than I, apically constricted and with sensilla.

Rostrum. Length 0.48-0.59 mm, anterior portion ca. 2 × broader than long, rostrum/pronotum length ratio 0.56-0.63, rostrum length/width ratio 1.01-1.19. Dorsal outline of rostrum square, posterior half of dorsal surface strongly rugose. Rostrum in lateral view sub-rectangular; apical margin with 2 large vibrissae. Nasal plate very strongly defined by Y-shaped, impressed lines, convex, integument partially covered with white-opalescent scales. Margins of mandibular incision directed 30° outward dorsally in frontal view. Ventrolateral sulci strongly defined, beginning as a narrow sulcus dorsad of insertion point of mandibles, running parallel to scrobe, terminating in a ventral fovea. Dorsal surface of rostrum with median sulcus running dorsally from fovea at posterior end of nasal plate to midpoint between posterior margins of eyes. Rostrum ventrally lacking foveae in line with insertion point of mandibles. Oral cavity with lateral margins weakly curved.

Antennae. Dorsal margin of scrobe overhanging slightly and forming a minute tooth, anterior to margin of eye by 2/5 of length of eye. Terminal funicular segment somewhat oblong in dorsal view, lacking appressed scales, having instead a covering of apically-directed pubescence with interspersed sub-erect setae. Club similar in length to funicular antennomeres IV–VII, 2.25-2.5 × as long as wide.

Head. Eyes separated in dorsal view by 4-5 × their anterior-posterior length, set off from anterior prothoracic margin by 2/5 of their anterior-posterior length.

Pronotum. Length/width ratio 0.83-0.86, sub-cylindrical to conical; widest near anterior 1/4 just before anterior constriction; surface deeply and coarsely punctate. Anterior margin nearly straight, subtly incurving mesally, lateral margins curved anteriorly and widening into a bulge near anterior 1/4, nearly straight to posterior margin thereafter; anterior constriction subtle in some specimens, posterior margin incurved. Pronotum in lateral view with setae that reach beyond anterior margin; these setae becoming evenly longer laterally, nearly reaching posterior margin of eye at their maximum length. Anterolateral margin with a reduced tuft of post-ocular vibrissae present, consisting of 3-6 setae, usually only 1-2 setae emerging beyond fringe of appressed scales near ventral margin of eye; vibrissae achieving a maximum length 3/5-2/3 × anterior-posterior length of eye.

Scutellum. Margins straight.

Pleurites. Metepisternum covered by elytron near posterior 1/2 of metasternum.

Thoracic sterna. Mesocoxal cavities separated by distance 1/4 × width of mesocoxal cavity. Metasternum with transverse sulcus apparent; metacoxal cavities separated by 2-2.5 × their width.

Legs. Tibiae and trochanters of all legs with a single, hair-like, brown seta positioned on mesal surface, approximately 1.5-2 × length of adjacent setae. Profemur/pronotum length ratio 0.93-1.06; profemur with distal 1/5 produced ventrally as an obliquely rounded projection covering tibial joint. Protibia/profemur length ratio 0.84-0.93; protibia moderately stout; mucro present as a laterally projected tooth equal in length and nearly 2 × as wide as nearby setae, triangular. Protarsus with tarsomeres I-II jointly similar in length to V. Metatibial apexwith almond shaped convex ity ringed by 9-10 short, spiniform setae.

Elytra. Length/width ratio 3.14-3.24; widest at anterior 1/3-2/5; anterior margins jointly 1.5-1.75 × wider than posterior margin of pronotum; lateral margins sub-parallel after anterior 1/6, more strongly rounded and converging in posterior 1/3. Elytra in lateral view slightly convex; posterior declivity angled at nearly 80° to main body axis. Elytral striae deeply and distinctly punctate; punctures separated by 2-4 × their diameter.

Abdominal sterna. Ventrite III elevated and set off from IV along lateral 1/3s of its length. Sternum VII mesally 1/2-3/5 as long as wide, sub-triangular; anterior margin weakly curved. Tergum. Pygidium (tergum VIII) sub-conical; medial 1/2 of anterior 1/3 of pygidium less sclerotized.

Sternum VIII. Anterior laminar edges each incurved forming a 115° angle with lateral margin; a less sclerotized region present anteriorly with anterior and lateral edges straight, latter diverging anteriorly; sclerotized region with pores throughout, less sclerotized medially; posterior edge strongly incurved and alate.

Ovipositor. Coxites less sclerotized postero-laterally, becoming more sclerotized anteriorly and medially, sclerotized regions porose, 2/3 as broad as long in dorsal view; styli 2/3 × length of coxites (latter short).

Spermatheca. Comma-shaped; collum expanded, apically with a long, perpendicular, cylindrical projection, nearly equal in length to collum; collum short, slightly swollen, 2/3 length of ramus, sub-contiguous with, and angled at 90° to ramus; ramus elongate, bulbous, 2 × thickness of corpus, basally constricted; corpus not swollen, equal in width to cornu; cornu elongate, apically, gradually narrowed, strongly recurved in basal 1/2, forming an inner angle of ca. 45° to collum and corpus, abruptly bent outward ca. 60°, then incurved.

Male.

Similar to female, except where noted. Length 2.77-3.12 mm, width 0.98-1.16 mm, length/width ratio 2.58-2.90. Rostrum length 0.40-0.50 mm, rostrum/pronotum length ratio 0.57-0.73, rostrum length/width ratio 1.05-1.17. Pronotum length/width ratio 0.86-0.91. Profemur/pronotum length ratio 0.97-1.22, protibia/profemur length ratio 0.84-0.88. Elytra length/width ratio 1.23-3.15.

Elytra. Elytral declivity less angulate, forming a 60° angle to main body axis, but otherwise as female.

Abdomen. Sternum VII 2/5-1/2 × as long as wide. Tergum VII with posterior margin straight. Pygidium (tergum VIII) with posterior margin arcuate laterally, straight along mesal 1/3; posterior 2/3 punctate; anterior 1/3 rugose.

Sternum VIII. Lateral and mesal margins straight. Laminar alae located on lateral 1/3 of posterior margin, 1/2 as long as sub-quadrate portion of lamina. Mesal 1/3 without projection. Tegmen. 2/3 × length of pedon. Aedeagal pedon. Length/width ratio 5.89-7.82; lateral margins parallel, abruptly, more strongly converging in region of ostium. In lateral view, width of pedon even throughout in anterior 2/3, ventral margins in posterior 1/3 becoming straight towards apex, then curving to meet dorsal margins at a sharp apical point; apexacutely angulate. Flagellum apically with a reduced conical sclerite. Aedeagal apodemes slightly shorter than pedon.

Etymology.

Named in reference to the deep and distinct punctures covering the dorsum; puteus = pit, puticulus = diminutive of pit (small pit), puticulatus = with little pits; Latin adjective ( Brown 1956).

Material examined.

Holotype - female "TEX. Big Bend, N.P. 6.5 mi. S, W. Grapevine, Hills Ranch/ at night, VI-3-1970, L & C.W. O’Brien” (CWOB); Paratypes, same label information as female holotype (CWOB: 10 females, 8 males) [3 females, 2 males deposited at CMNC]; "TEX. Terrel Co., 25 mi. SE. Dryden, 8-X-1982, E.G. Riley" (CWOB: 6 females, 10 males) [2 females, 3 males deposited at CMNC]; "TEX. Big Bend, N.P. 6.5 mi., SW. Grapevine, Hills Ranch/ Parthenium incanum [non-focal], at night, 3-26-1970" (CWOB: 4 females, 1 male); "TEX. Big Bend, N.P. 6.5 mi., SW. Grapevine, Hills Ranch/ at night, L & C.W. O’Brien, III-27-1970" (CWOB: 2 females, 5 males); "TEX. Big Bend, N.P. 2.5 mi. S, W. Grapevine, Hills Ranch/ at night, L & C.W. O’Brien, VI-3-1970" (CWOB: 2 females, 2 males); "TEX. Big Bend, N.P. 5300', Green Gulch, VI-8-1970/ Parthenium incanum [non-focal], at night, L & C.W. O’Brien” (CWOB: 1 male); "Dryden Tex, VI-11-1930/ B.E. WHITE, Collection, 1962 Gift/ Minyomerus , Det. R.S. Anderson 1994" (CAS: 2 males); "Chisos Mts, VII 18 Tex/ J.W. Green, Collector/ J.W. Green, Collection" (CAS: 2 females); "Chisos Mts, VII 19 Tex/ J.W. Green, Collector/ J.W. Green, Collection" (CAS: 1 females); "Sanderson, Texas, VI-10-30/ JO Martin, Collector/ Isodacrys ovipennis Schffr. [misidentification]" (CAS: 4 females, 5 males).

Distribution.

This species has been found in the Big Bend region of Texas (USA), and is likely also found in Coahuila and Chihuahua (Mexico) (Fig. 52).

Natural history.

Associated with creosote bush ( Larrea tridentata [DC.] Coville [non-focal]; Zygophyllaceae [non-focal]) and Mariola ( Parthenium incanum Kunth [non-focal]; Asteraceae [non-focal]).