Parallocorynus (Eocorynus) chemnicki, O’Brien & Tang, 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 : 55-56

Parallocorynus (Eocorynus) chemnicki Tang and O’Brien, new species

Figures: habitus: 93 – 96; antennal pockets: 124; male genitalia: 171 – 172, 196, 236; female genitalia: 263.

DESCRIPTION—Body medium-sized (range 3.2 – 3.9 mm, mean = 3.4 mm, n = 4), not robust, elongate-oval; body orange-brown, elytra uniformly black.

Male (holotype). Rostrum: long, 1.44 X longer than pronotum, black; coarsely, scarcely rugosely, substriately punctate from base nearly to apex; weakly expanded in distal half, weakly somewhat evenly curved in lateral view; color black, except apex dark brown. Head: between eyes, on forehead and behind eyes black with few, sparse, large punctures, with distance between punctures approximately 3 X width of punctures; punctures between eyes 2 X diameter of punctures posterior to transverse postocular groove; forehead with distinct, long, narrow, median sulcus; bare spot without punctures present behind forehead and sulcus, with diameter approximately 0.50 X width of eye; forehead strongly narrowed apically, 0.79 X as wide between median basal margin and apical margin of eyes; color uniformly black in dorsal view, ventral surface orange-brown. Antennae: with scape brown, 1.67 X longer than eye and 1.07 X longer than desmomeres 1+2, 1 – 2 elongate, 3 – 5 round, 6 – 7 more transverse and shorter; scape reddish brown, 1 – 7 brown to piceus; club with rhopalomeres 1 – 2 piceus to black, basal 2/5 of apical rhopalomere piceus, apical 3/5 dark brownish-orange. Prothorax: transverse, 1.28 X wider than long; anterior margin emarginate, fringed with hairs of length equal to width of pronotal collar; apex moderately narrow, evenly roundly expanded to distal 1/3, there subparallel until basal 1/5, there strongly rounded to base; lateral margins not denticulate, with large coarse punctures; disc with moderately coarse, moderately separated punctures (distance between punctures 2 – 3 X own width); laterally subrugose; uniform orange-brown except at center of anterior margin, there thin and translucent and appearing black. Scutellum: with lateral margins basally subparallel; apically narrowed and rounded, with dense small punctures. Elytra: 0.55 X as wide as long; subparallel behind rounded humeri to near declivity, there suddenly evenly narrowed to rounded moderately emarginate apices; unevenly coarsely punctured, humeral area with discrete punctures, medially and apically moderately rugosely punctured. Legs: very robust, procoxae orange-brown, weakly convex, lacking processes; protrochanter orange-brown, with sclerotized nub at apex; femora orange-brown, profemora strongly asymmetrically swollen, without apical pit-like impression receiving base of tibia, proximal to distal apex with large spine located just posterior to, and in line with, apical pit along ventral inner surface, ventral inner surface granulate at area of greatest swelling; protibiae black, stout in lateral view, with base rounded with strong rounding bend, lacking inner tooth, inner surface weakly medially broadly excavate from base to near apex, subcarinate margins of groove denticulate, apex with small anterior mucro and subequal posteriorly directed tooth. Length, pronotum and elytron: 3.9 mm.

Female. Same as male except: Rostrum: 1.95 X longer than pronotum; longest in Allocorynina ). Prothorax: 1.42 X wider than long; apex narrowed, sides more or less evenly rounded to narrowed base. Elytra: 0.59 X as wide as long.

Genitalia and Associated Structures— Male. Length of penis and apodemes together 1.22 mm. Penis: robust, 0.20 mm wide (n = 1), in dorsal view sides subparallel in basal portion, slightly constricted in apical portion, with pronounced bulge near gonopore; apodemes slightly shorter than penis (Figs. 171 – 172); apex tapering distad evenly for 2/3 of length, then angle of taper becoming more pronounced and lateral margins becoming convex before protruding rounded point (Fig. 196). Tegmen: apical plate elongate, 1.45 X longer than wide. Female. Sternite VIII: (Fig. 263) arms diverging from junction with apodeme with increasing angle between arms until rounded bend (not angulate bend; specimen in figure 263 bent—arms viewed at oblique angle) and converging in posterior ~ 1/3; band of setae ~ half width of arms.

Etymological Note— This species is named in honor of Jeff Chemnick, who assisted in the collection of the type specimens of this species, and for his contributions to the taxonomy, ecology and conservation of Mexican cycads.

Remarks— This species is readily distinguished from the other member of the subgenus by its black colored forehead on an otherwise uniformly brown head (exclusive of the eyes and rostrum) versus uniform brown in P. schiblii and by the black elytra versus the predominantly brown elytra of P. schiblii .

Biology— Adults currently known from a single host, Dioon califanoi , where this species can be found together with Parallocorynus (Parallocorynus) gregoryi . Larvae attributable to P. chemnicki also have been found in male cones of D. purpusii .

Range— Known from Mexico, state of Puebla.

Material Examined— Holotype (by designation) male with the following labels: 1) [rectangular; white; printed in black ink] MEX., Puebla, Oax. Border, Teotitlán, [GPS coord. omitted], ex Dioon califanoi ♂ cone, 7-XI-2012, W. Tang ; 2) [rectangular; red; printed in black ink] HOLOTYPE ♂ / Parallocorynus (Eocorynus) / chemnicki/ Tang & O’Brien 2015 (CAS). Paratypes: same label data, (3). Paratypes (3) are deposited at CWOB and IEXA.

Concluding remarks

The family Belidae and its various subfamilies generally are considered to be relict groups ( Marvaldi et al. 2006). They are early members of the Curculionoidea that have been superseded in many geographic regions and ecosystems by more advanced lineages of weevils. The Allocorynina , however, are an exception to the rule in the sense that they have diversified in a relatively specialized niche, the reproductive structures of cycads in the New World, where they are involved in a pollination symbiosis with their hosts ( Norstog et al. 1986, 1992, Norstog & Fawcett 1989, Oberprieler 1995, Tang 1987, 2004). Recent DNA studies ( Nagalingum et al. 2011, Salas-Leiva et al. 2013) indicate that much of the diversity of modern cycads, including those in the New World, has evolved only within the last 12 million years. Much of the modern diversity of the Allocorynina likely arose contemporaneously during the adaptive radiation of their host lineages.

Fossils may indicate that the Allocorynina may have had an ancient distribution extending into Europe ( Legalov 2013), however, the fossil illustrated lacks many characters of the Allocorynina and may be an Attelabidae . The host associations of all known extant Allocorynina indicate that they are restricted to the cycad genera Dioon and Zamia and are absent from the New World cycad genera Ceratozamia and Microcycas ( Tang & O’Brien 2012). They have been found in all species of Dioon that have been sampled closely but are absent in many lineages of Zamia , particularly on the periphery of the range of Zamia in South America and the Caribbean. These host and geographic patterns and the results of molecular analysis ( Tang et al. in prep.) point to Dioon being the original host lineage of the Allocorynina and suggest that host-shifts onto Zamia may have been more recent.

We expect that more species of Allocorynina await discovery, particularly in the genera Parallocorynus and Rhopalotria in Mexico, Guatemala and Honduras, where many species of Dioon and Zamia have yet to be sampled adequately. Many of these weevils can be found only in dehiscing male cones in the field. In many populations of these two cycad genera, years may elapse between major periods of coning. Adult weevils usually are present only for a brief period of one or two months during the pollination season, when male cones are dehiscing. The subgenera Neocorynus and Eocorynus cannot be reared from pupae inside old male cones, as all other Allocorynina genera can be, and are especially difficult to find. More focused field work and surveys of those cycad species that have not been sampled undoubtedly will lead to a more complete understanding of the diversity in this group of weevils.