Parallocorynus (Dysicorynus) sonorensis 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 : 48-50

Parallocorynus (Dysicorynus) sonorensis O’Brien and Tang, new species

Figures: habitus: 77 – 80; antennal pockets: 120; male genitalia: 163 – 164, 192, 232; female genitalia: 259.

DESCRIPTION—Body small to medium-sized (range 2.2 – 3.8 mm, mean = 3.4 mm, n = 19, slender to slightly robust, elongate-oval; unicolored brown.

Male (holotype). Rostrum: long, 1.18 X longer than pronotum; yellowish orange; not denticulate; dorsally and laterally, strongly, rugosely punctate; weakly expanded near apex; weakly rather evenly curved in lateral view. Head: behind eyes with sparse, very fine, shallow punctures; forehead between eyes with moderately dense, moderately coarse, shallow punctures; forehead with distinct, moderately long, narrow, median sulcus; forehead strongly narrowed apically, 0.63 X as wide between median basal margin and apical margin of eyes. Antennae: with scape 1.29 X longer than eye and as long as desmomeres 1+2, 1 – 4 elongate, 5 – 7 shorter and transverse; scape, desmomeres, and club all pale yellowish. Prothorax: strongly transverse, 1.45 X wider than long; apex moderately narrow, weakly rounded to subparallel sides, suddenly rounded to narrowed base; lateral margins moderately distinct, not denticulate, with large, shallow, moderately fine punctures; disc with fine, small, moderately dense, sparse, narrowly separated punctures; pair of foveae present on disc, ca. 1/4 from basal margin and 1/8 from lateral margin; uniform yellowish orange. Scutellum: with lateral margins straight; apically broadly rounded; with scarcely visible, small, fine punctures; subglabrous. Elytra: 0.67 X as wide as long; evenly expanding 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, shining; uniformly yellowish 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: 4.00 mm.

Female. Same as male except: Rostrum: 1.32 X longer than pronotum; smooth, nearly impunctate. Length, pronotum and elytron: 4.20 mm.

Genitalia and Associated Structures— Male. Length of penis and apodemes together 1.32 – 1.44 mm (n = 2). Penis: in dorsal view lateral margins slightly constricting basal to gonopore and slightly bulging apicad to gonopore (Figs. 163 – 164), apex tapering to blunt point, length from gonopore to apex about twice as long as wide (see Fig. 192). Tegmen: distal margin with fewer than 20 setae (Fig. 232). Female. Sternite VIII: (Fig. 259) 0.94 – 1.00 mm long (n = 2), arms ~ half as long as apodeme, diverging from apodeme at more or less constant angle (~ 70 – 75˚) between arms for 2/3 of length, then forming sharp angulate bend, then converging.

Intraspecific Variation— The rostral length relative to the pronotal length of males = 1.02 – 1.11 (mean = 1.06, n = 10) and of females = 1.27 – 1.42 (mean = 1.32, n = 9). The pronotal width relative to the pronotal length of males = 1.32 – 1.41 (mean = 1.36, n = 10) and of females = 1.34 – 1.48 (mean= 1.42, n = 9).

Etymological Note— This species is named to reflect its host species, Dioon sonorense .

Remarks— Molecular analysis of the 16S rRNA mitochondrial gene indicates P. sonorensis is genetically distinct from P. andrewsi inhabiting D. tomasellii in southern Sinaloa state ( Tang et al. in prep.).

Biology— This species lives and reproduces on the male cones of Dioon sonorense .

Range— Known from western Mexico in the state of Sonora . Its host, Dioon sonorense , occurs as scattered populations in Sonora and the northern section of the state of Sinaloa.

Material Examined— Holotype (by designation) male with the following labels: 1) [rectangular; white; printed in black ink] Mexico, Son. [Sonora]/ Mazatlan [Mazatán] 29-IV-/ 2004, A. Vovides/ J. Gonzalez; 2) [rectangular; white; printed in black ink] on Dioon sonorense ; 3) [rectangular; red; printed in black ink] HOLOTYPE ♂ / Parallocorynus (Dysicorynus) / sonorensis/ O’Brien & Tang 2015 (CAS). Paratypes: same label data, (69) are deposited at ANIC, BMNH, CAS, CMNC, CSCA, CWOB, FMNH, FSCA, IEXA, UNAM.

Subgenus Neocorynus O’Brien and Tang , new subgenus

Type species: Parallocorynus (Neocorynus) inexpectatus O’Brien and Tang, new species

DIAGNOSIS. The subgenus Neocorynus can be distinguished from other Allocorynina by the following diagnostic character: male profemoral ventral surface with a field of granules that is 3 or more granules in width and without any stout spines. It may be further distinguished from other subgenera of Parallocorynus by the degree of sexual dimorphism in RL/PL, with females on average 51 – 53% greater in this measurement than males; in other subgenera of Parallocorynus females are on average only 11 – 35% greater in this measurement than males.

DESCRIPTION. Body small to medium-sized (BL = 2.6 – 3.8 mm, mean = 3.4 mm, n = 28); moderately robust, elongate-oval; dorsal surface bicolored orange to black, other parts of body and legs orange-brown to brown.

Male. Rostrum: 0.99 – 1.21 X as long as pronotum (n = 19). Antennae: scape length = 1.11–1.56 X eye length (n = 10; mean for each species = 1.18–1.46) and 1.26–1.49 X length of desmomeres 1+2 (n = 10; mean for each species = 1.30–1.39); width of antennal club pits <or ~ diameter of socket for club rhopalomere (Figs. 121–122). Prothorax: pronotal width/pronotal length (PW/PL) = 1.11 – 1.24 [mean = 1.16 (lowest for Allocorynina ), n = 36]; notopleural suture short and not reaching anterior margin of prosternum; distance from anterior margin of procoxae to anterior margin of prosternum on average 4.7 – 5.6 X distance from posterior margin of procoxae to posterior margin of prosternum. Legs: profemora asymmetrically swollen, ventral surface with field of granules, 3 or more granules in width and without any stout spines (Fig. 275).

Female. Same as male except: Rostrum: 1.55 – 1.76 X longer than pronotum (n = 14), on average 50 – 65% greater in two species with known females. Antennae: scape length = 1.24–1.54 X eye length (n = 10; mean for each species = 1.30–1.54). Prothorax: PW/PL = 1.14 – 1.27 [mean = 1.21 (lowest for Allocorynina ), n = 29), on average 4% greater in females than in males with some overlap between sexes within species. Legs: Profemora not asymmetrically swollen and without granulations or spines on ventral surface.

Genitalia and Associated Structures— Male. Length of penis and apodemes together 1.04 – 1.22 mm (n = 8). Penis: in dorsal view sides subparallel or slightly converging toward apex, bulging slightly near gonopore, length to width ratio 2.7 – 3.0 (Figs. 165 – 168), relatively wide and short compared with subgenera Parallocorynus and Dysicorynus ; apex in dorsal view narrowed more or less evenly to rounded point (Figs. 193 – 194); transverse dorsal sclerotized bridge present at base; apodemes approximately same length as basal section of penis, slightly concave on inner surface, in lateral view widened gradually from base until narrowed at rounded apex. Internal sac: with endophallus in retracted position protruding well beyond basal part of penis, sometimes beyond base of apodemes, distal section with elongate band of scales, one on each side, sinuate endophallic strut along ventral midline absent (Figs. 166, 168), sclerotized endophallic dart visible within apex. Tegmen: apical plate in lateral view with width <1/4 length of plate, in dorsal view slightly narrowed distad to truncate or slightly rounded apex, apex without dorsal shelf, apical plate rigid except posterior margin curling ventrally along transverse axis, or not; fringed with setae numbering typically fewer than 25, in dorsal view typically only setae in apical corners visible, those along center of apex pointing ventrally; length of longest setae <width of apical plate in dorsal view (Figs. 209 – 210, 233 – 234). Female. Sternite VIII: with arms ~ half as long as apodeme, diverging from apodeme with gradually increasing angle between arms for ~ 2/5 of length, then curved inward but without sharp angulate bend, then converging in final half of length, apices not touching; length of band of setae connecting apices of arms <greatest width of arms (Figs. 260 – 261). Spermathecal tube: uncoiled length <half length of sternite VIII.

Etymological Note— The name of the subgenus is masculine and latinized from the Greek words neos (new) and koryne (club), indicating its close relationship to other subgenera in the genus Parallocorynus .

Remarks— As here delimited this subgenus corresponds to the “edule ” species group of Tang & O’Brien (2012). Morphology of the genitalia and molecular analysis of the 16S rRNA gene ( Tang et al. in prep.) indicate this subgenus is related most closely to the subgenera Eocorynus and Dysicorynus . Adults of the subgenera Parallocorynus and Neocorynus may co-occur within individual dehiscing male cones of the Dioon edule species complex. The larval stages of the two subgenera appear to feed in different parts of the cone, in a form of niche partitioning. The larvae of the subgenus Neocorynus are highly mobile and appear to feed within the cone axis ( Tang , pers. obser.) while those of Parallocorynus are confined inside the sporophylls ( Vovides 1991, Tang , pers. obser.). Furthermore, the larvae of the subgenus Neocorynus , unlike all other Allocorynina (except the subgenus Eocorynus ), do not pupate within male cone sporophylls, but exit the cone to pupate either in another part of the plant or outside the plant entirely. Unlike in the subgenus Parallocorynus , adults of this subgenus have never been reared from cones. These striking differences in larval and pupal behavior of Neocorynus indicate a fundamental shift in their life cycle compared to all other Allocorynina (except the subgenus Eocorynus ) studied so far.

Host and Geographic Distribution— This lineage is restricted to Mexico and all known members of this genus have been found only in fresh male cones of the narrow-leaflet Dioon edule-angustifolium species complex; adults have been captured only from dehiscing male cones in the field.