Rhopalotria (Allocorynus) mollis ( Sharp, 1890 )

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 : 28-30

Rhopalotria (Allocorynus) mollis ( Sharp, 1890)

Figures: habitus: 33–36; antennal pockets: 109; male genitalia: 141–142, 181, 221; female genitalia: 248.

Allocorynus mollis Sharp, 1890:46

REDESCRIPTION—Body small (range 2.2–2.6 mm, mean = 2.4 mm, n = 12), robust, broad-oval; body and elytra light orange-brown, head darker orange-brown.

Male (lectotype). Rostrum: moderately long, 0.96 X as long as pronotum, light brown; coarsely, rugosely punctate in basal 2/3, moderately more sparsely punctate in apical 1/3, gradually weakly expanded in apical 1/3; slightly bent at center in lateral view. Head: light brown; entire dorsum including forehead, rugosely punctate, width of forehead between apical margin of eyes 0.56 X width between median basal margin of eyes; minimum distance between eyes less than length of eye. Antennae: scape length 0.78 X as long as eye and 1.27 X longer than desmomeres 1+2, 1 ovate and as wide as scape, 2–3 narrower and elongate, 4 transitional from elongate to rounded, 5–7 rounded, submoniliform; antennae slightly paler in color than head and rostrum. Prothorax: strongly transverse, 1.43 X wider than long; apex moderately narrow, evenly expanded to middle, there subparallel to slightly rounded base; lateral margins not denticulate; disc with fine, shallow, moderately dense, evenly distributed, not contiguous punctures, becoming coarse and subcontiguous on lateral margins; uniform pale orange-brown. Scutellum: subquadrate, with moderately large shallow dense punctures. Elytra: 0.60 X as wide as long; subparallel behind rounded humeri, to slightly expanded near declivity, there suddenly evenly narrowed to broadly rounded deeply emarginate apices; unevenly coarsely punctured, humeral area with discrete punctures; uniform pale orange-brown. Legs: robust, procoxae protruding, with pair of blunt inner apical processes; profemora very weakly asymmetrically swollen, with apical pit receiving base of tibia, basal margin of pit with very small sclerotized protrusion; protibiae stout in lateral view, with base obtusely rounded, no tooth on inner surface near base, inner surface medially broadly excavate from base to near apex, receiving ventral margin of femur, margins of excavation serrate, apex with small anterior mucro and equally small posterior tooth. Length, pronotum and elytron: 2.56 mm.

Female. Same as male except: Rostrum: 1.32 X longer than pronotum, smooth, nearly impunctate, very weakly expanded apically. Prothorax: sides more or less evenly rounded from narrow apex to slightly narrowed base; 1.53 X wider than long. Legs: protibiae normally developed, without basal bend, without basal slot to receive femoral tooth, and without excavation on inner surface or serration on margins. Length, pronotum and elytron: 2.49 mm.

Genitalia and Associated Structures— Male. Length of penis and apodemes together 0.68 mm (n =1), strongly curved ventrally (Figs. 141–142). Tegmen: apical visor relatively long, ~ half own width (Fig. 221). Female. Sternite VIII: 0.73–0.77 mm long (n = 2), arms slightly longer than apodeme, diverging from apodeme with 20˚angle between arms for ~ half of length, then becoming subparallel, forming V-shape (Fig. 248).

Intraspecific Variation— The rostral length relative to the pronotal length of males = 0.94–1.01 (mean = 0.97, n = 9) and in females = 1.27–1.36 (mean = 1.31, n = 3); the pronotal width relative to the pronotal length of males = 1.43–1. 52 (mean = 1.48, n = 9) and in females = 1.47–1.60 (mean = 1.54, n = 3).

Remarks— Rhopalotria mollis is closely related to R. furfuracea ; this is part of a cryptic species complex and can be distinguished by molecular analysis of the 16S rRNA gene ( Tang et al. in prep.). The 15 adult specimens of this species that were available for study fall within the lower size limits for R. furfuracea and are very similar morphologically to specimens of R. furfuracea in this size range. The male specimens available do not exhibit the swollen profemora with the ventrodistal spine present in the major males of R. mollis and it is unknown whether this species attains the larger size ranges of R. furfuracea . After the original description the type series is described as follows: “Unfortunately nearly all of them are so immature as to be nearly valueless” ( Sharp 1890). Examination of the type series by the authors, however, reveals that specimens range from partially sclerotized to near fully sclerotized. The original author may have interpreted the soft-bodied condition of these specimens, typical in Allocorynina , as being teneral. These and other fully sclerotized specimens from Oaxaca exhibit the dark brown head of R. furfuracea ; however, the antennae and to a lesser extent the prothorax and elytra are paler than those of R. furfuracea . The most distinctive diagnostic characters separating these species, however, are: 1) the dorsal interocular distance relative to head width at the eyes which in R. mollis = 0.276 –0.310 (mean = 0.296, n = 12) and in R. furfuracea = 0.314 –0.377 (mean = 0.353, n =36) and 2) the shape of the arms of sternite VIII in females, which is V-shaped in R. mollis , but U-shaped in R. furfuracea (Figs. 248–249). The known host species of R. furfuracea are separated from the known host species for R. mollis by the Sierra Madre Occidental.

Biology— Known to reproduce in the male cones of Zamia paucijuga , which is the sole recognized species of Zamia along the Pacific slope of Mexico from western Chiapas north to Nayarit. The cotype specimens were collected in Durango, the state bordering the northern boundary of Nayarit, and thus are slightly beyond the known northern extent of this host Zamia . It is likely that the cotype series was collected from an undiscovered population of this host Zamia . No other Zamia species occur in this region and Z. paucijuga is geographically disjunct from other Zamia species occurring east and south. One specimen of the cotype series originates from Tapachula in eastern Chiapas, where the likely host is another species of Zamia , Z. herrerae . This specimen is tentatively retained within R. mollis , pending further study.

Range— Mexico, known from the states of Durango, Chiapas and Oaxaca; it is likely found with its known host, Zamia paucijuga , which is widely distributed in western Mexico in the states of Chiapas, Colima, Guerrero, Jalisco, Michoacán, Nayarit and Oaxaca and on María Cleofas Island ( Vovides & Chemnick, 2010) .

Material Examined— Lectotype (by present designation) male with the following labels: 1) [mounting board for specimen: rectangular; white; hand-written in black ink] ♂ / Allocorynus / mollis Type/ D.S./ Ventanas,/ Durango Höge; 2) [circular; white bordered with orange; printed in black ink] Type; 3) [rectangular; white; printed in black ink] Ventanas/ Durango / Höge; 4) [rectangular; white; printed in black ink] B.C.A. Col. IV.3./ Allocorynus / mollis/ Sharp; 5) [rectangular; red; printed in black ink] LECTOTYPE ♂ / Rhopalotria (Allocorynus) / mollis/ O’Brien & Tang 2015 (BMNH). Paralectotypes: same label data, (9), (BMNH). MEXICO: Chiapas: Tapachula, Höge (1); Oaxaca: San Bartolomé Loxicha, [GPS omitted], distur. oak woodland, elev. 708m, ex. Zamia paucijuga male cones, coll. J. Chemnick 21May 2004 (5). Specimens (6) are deposited in BMNH, CAS, CWOB, FSCA, IEXA.