Parallocorynus (Parallocorynus) norstogi O’Brien, 2015

O’Brien, Charles W. & Tang, William, 2015, Revision of the New World cycad weevils of the subtribe Allocorynina, with description of two new genera and three new subgenera (Coleoptera: Belidae: Oxycoryninae), Zootaxa 3970 (1), pp. 1-87 : 43-44

Parallocorynus (Parallocorynus) norstogi O’Brien and Tang, new species

Figures: habitus: 65–68, 268; antennal pockets: 117; male genitalia: 157–158, 189, 229, 239; female genitalia: 256.

DESCRIPTION—Body small to large (range 2.4–5.0 mm, mean = 4.1 mm, n = 50), slender to robust, elongate-oval; bicolored, orange and brown.

Male (holotype). Rostrum: long, as long as pronotum, blackish brown; strongly denticulate on each margin and unevenly medially from base nearly to apex; weakly expanded near apex, very weakly somewhat evenly curved in lateral view. Head: just behind eyes and forehead between eyes with moderately dense, moderately fine, shallow punctures; forehead with distinct, moderately long, narrow, median sulcus; forehead strongly narrowed apically, 0.69 X as wide between median basal margin and apical margin of eyes. Antennae: scape 1.33 X longer than eye and 1.20 X longer than desmomeres 1+2, 1–4 elongate, 5–7 shorter and transverse; scape and desmomeres 1–4 reddish brown, 5–7 piceus to black; club with rhopalomeres 1–2 piceus to black, apical rhopalomere pale yellowish in apical half. Prothorax: transverse, 1.21 X wider than long; apex moderately narrow, evenly roundly expanding to basal 1/4, there strongly rounded to base; lateral margins not denticulate, with large, shallow, moderately fine punctures; disc with fine, small, sparse, widely separated punctures; uniform dark orange. Scutellum: lateral margins straight and oblique, forming triangle; apically narrowed and rounded, with moderately dense, small punctures and short, fine, recumbent, pale colored setae. Elytra: 0.60 X as wide as long; evenly expanded behind rounded humeri to declivity, there suddenly evenly broadly rounded to slightly emarginate apices; with small, fine, dense, well-separated punctures on entire surface, overall rather smooth; uniformly dark brown. Legs: moderately robust, procoxae weakly convex, lacking processes; profemora moderately, symmetrically swollen, with small apical pit-like impression receiving base of tibia, apical margins lacking tooth or process, surface very finely wrinkled, appearing smooth; protibiae moderately stout in lateral view, with base angulately rounded with obtuse bend, lacking inner tooth, inner surface very weakly medially narrowly excavate from middle to near apex, margins of groove denticulate, apex with small anterior mucro and subequal tooth. Length, pronotum and elytron: 4.70 mm.

Female. Same as male except: Rostrum: 1.33 X longer than pronotum. Prothorax: 1.34 X wider than long; apex narrow, apical 1/3 strongly rounded, there subparallel to slightly narrowed broad base. Length, pronotum and elytron: 4.50 mm.

Genitalia and Associated Structures— Male. Length of penis and apodemes together 1.59–1.64 mm (n = 2) (Figs. 157–158). Penis: in dorsal view apex at gonopore noticeably widening, then tapering immediately, sides curved, convex, about as long as wide; gonopore, with sac in retracted position, capped with sclerotized knob (Fig. 189). Internal sac: when fully extruded with dorsal pleats, covered with scales on lateral and ventral surfaces (Fig. 239). Tegmen: distal margin with more than 20 setae (Fig. 229). Female. Sternite VIII: (Fig. 256) 1.29–1.47 mm long (n = 3), arms half–2/3 as long as apodeme, diverging from apodeme at slight angle (<15˚) between arms for ~ 1/3–2/5 of length, then making sharp angulate bend outward and becoming wider, angle between arms ~ 75˚ for ~ 2/5 of length, then arms forming sharp angulate bend inward becoming subparallel to slightly convergent.

Intraspecific Variation— The rostral length relative to the pronotal length of males = 0.96–1.10 (mean = 1.01, n = 16) and of females = 1.27–1.48 (mean = 1.37, n = 12); the pronotal width relative to the pronotal length of males = 1.23–1.32 (mean = 1.27, n=16) and of females = 1.28–1.46 (mean = 1.34, n = 12).

Etymological Note— This species is named in honor of the late Knut Norstog for his contributions to cycad reproductive and pollination biology.

Remarks— This species is closely related to P. perezfarrerai and the two can be most readily distinguished from other species of Parallocorynus by the shape of sternite VIII of the female (Figs. 256–257), which has arms remaining parallel or subparallel in the apical 1/3 of their length and by the presence of a sclerotized knob at the gonopore in the male genitalia when the internal sac is in a retracted position (Fig. 189). Parallocorynus norstogi can be distinguished from P. perezfarrerai by its greater degree of black coloration of the elytra and by the generally shorter elytral length relative to the pronotal length in females. Parallocorynus norstogi is found together with Parallocorynus (Neocorynus) inexpectatus in the male cones of Dioon angustifolium and related forms of Dioon north of the Mexican transvolcanic belt. Female individuals of the two species are similar, but can be distinguished by RL/PL, which is larger (1.56–1.64) in P. inexpectatus and by the color of the forehead, which is concolorous with the pronotum in P. norstogi , and usually darker, and the hue is between the black rostrum and the light brown pronotum in P. inexpectatus .

Biology— This species is known to develop within cones of Dioon angustifolium and closely related forms of Dioon . Usually multiple larvae develop within a single sporophyll of a male cone. When a cone of Dioon angustifolium was brought into the lab, adults continued to emerge over 8 years; emerging in the hundreds in the first year and in diminishing numbers for the next 7 years (1971–1979) that the cone was retained ( Vovides 1991, Tang 1997, O’Brien, unpublished obs.). This extended period of emergence may be an adaptation to infrequent coning periods in the natural populations of its host plant, possibly due to occurance of severe droughts.

Range— Mexico, known from eastern Nuevo León, western Tamaulipas and eastern San Luis Potosi. Dioon populations with affinities to D. angustifolium also occur in the neighboring states of Hidalgo and Querétaro ( González-Astorga et al. 2005, Whitelock 2002).

Material Examined— Holotype (by designation) male with the following labels: 1) [rectangular; white; printed in black ink] MEX., N. L., 16 mi. / W. Linares 3600’, / VIII-15-1971 C&L/ O’Brien & Marshall; 2) [rectangular; white; printed in black ink] ex: male strobile / Dioon edule [ angustifolium ]; 3) [rectangular; red; printed in black ink] HOLOTYPE ♂ / Parallocorynus (Parallocorynus) / norstogi/ O’Brien & Tang 2015 (CAS). Paratypes: same label data, (614) and 2400’[sic], reared ex same male cone, emerged, Aug. 1973 (49), Aug. 1974 (24), 1976 (2), 1977 (4), 1978 (1), 1979 (2); MEXICO: N.L. [Nuevo León]: Ejido Los Alamos, Canon la Jarbon, 7–9.IX.1982, 24 ˚41’N., 99˚42’W, ex male strobile Dioon edule [ angustifolium ], T. Scheridan [Sheridan] P. (59); Ejido los Alamos, Canon la Jarbon, 24˚41’N., 99˚42’W., 1982, emerged ex male strobile Dioon edule [ angustifolium ], 17 Aug—15-IX.1983, T. Scheridan [Sheridan] P. Coll. (141); 16mi. W. Linares, Hwy. 58, IX-11-1982, C.W. & L. O’Brien & G.Wibmer, ex: male strobile Dioon edule [ angustifolium ] (795), reared ex same male cone, emerged, VIII-13–IX-7-1983 (266), summer-1983 (169), summer-1984 (21); S.L.P. [San Luis Potosi]: Hwy 70, 23k E. Cd. Valles, tunnel, [GPS coord. omitted], 335m, Dioon sp. “minima” cone ♂, 13-XI-2014, W. Tang (279); Tamps. [Tamaulipas]: Rancho Paso de las Nogales, Mpo. Villa Mainero, 500m, 99˚39’, 24˚32’, T. Sheridan P. ex: male strobile Dioon edule [ angustifolium ], 1982 (23). Paratypes (2449) deposited at ANIC, ASUT, BMNH, CAS, CMNC, CSCA, CWOB, EMEC, FMNH, FSCA, IADIZA, IEXA, IZCAS, MIUP, MNHN, STRI, UCFC, UNAM, USNM, ZMHB.