Two new Mexican species of Pharaxonotha Reitter , 1875 ( Coleoptera : Erotylidae ) from Ceratozamia tenuis ( Cycadales : Zamiaceae )

Two new species of Pharaxonotha Reitter, 1875 are described from Mexico. Illustrations are provided, as a key to identify Pharaxonotha known from the New World. The genus Ceratozamia Brongn (Zamiaceae) is recorded as a host to Pharaxonotha mexicana sp. nov. y P. tenuis sp. nov. for the first time. Specimens were collected directly in the cones of males and females of C. tenuis.

At present, 21 species of Cycadophila have been described, all of which are from Asia.In the New World, only 6 species of Pharaxonotha are recognized: two occur in Central America, Mexico, and the southeastern United States (Leschen and Skelley 2002), with two additional species in Costa Rica (Pakaluk 1988), one in Cuba (Chaves and Genaro 2005), and one in Puerto Rico (Franz and Skelley 2008).Pharaxonotha and two other genera of weevils are considered the primary pollinators of many Central America and Caribbean cycads (Franz and Skelley 2008).Most of the species of Pharaxonotha distributed in the New World have been found associated with the genus Zamia, and only one with Mycrocycas (Miq.) A. DC.: P. clarkorum Pakaluk, 1988 (Z. skinneri); P. confusa Pakaluk, 1988 (Z.fairchildeana); P. esperanzae Chaves and Genaro, 2005 (M.calocoma); P. floridana (Casey, 1890) (Z.pumila) and P. portophyla Franz & Skelley, 2008 (Z. amblyphyllidia and Z. portoricensis); whereas, P. kirschii Reitter, 1875 is considered a pest of stored products (Pakaluk 1988;Chaves and Genaro 2005;Franz and Skelley 2008).To date, a few species of Pharaxonotha has been reported as associated with the genus Ceratozamia Brongn (Tang et al. 2018); moreover, the new species of Pharaxonotha described here were collected in the same host, C. tenuis.The objective of this study is therefore to describe the adults of two species of Pharaxonotha associated with this cycad.

MATERIALS AND METHODS
From 2015 to 2017, cones of C. tenuis were visited in the locality of Tlachinola, in the municipality of Coacoatzintla, Veracruz State, Mexico, in order to evaluate the development of reproductive structures in both sexes.During these trips, small beetles were found in the cones of both sexes.Insects were collected in small vials, preserved in 96% ethanol and taken to the laboratory.These insects were subsequently identified in the laboratory as members of Pharaxonotha.Most of the specimens collected were found in the male cones, and only a few in the female cones (see type material).
The specimens were observed using a Stemi DV4 stereomicroscope.Photographs illustrating structures in detail were taken using an image processing system (VELAB microscope model , and the images were merged using the image stacking software Combine ZP.Habitus photographs were taken through a Nikon SMZ25 stereoscopic microscope.Permanent microscope slides were prepared using the techniques described by Santiago-Jiménez (2010).The terminology used here mainly follows Franz and Skelley (2008), with some references to Chaves and Genaro (2005) and McHugh et al. (1997) for comparative purposes.However, the terms used for the adult male terminalia was based on Wanat (2007).
Type and paratype specimens are deposited in the following collections: IEXA-Instituto de Ecología, A. C., Xalapa, Mexico (Ms. Sc. L. Delgado) CNIN-Colección Nacional de Insectos, Instituto de Biología, Universidad Nacional Autónoma de México, Mexico City (Dr.S. Zaragoza) Systematics Leschen (2003) proposed three characters to distinguish the Pharaxonothinae subfamily: 1) lateral pockets present on the mentum; 2) presence of multitubulate cuticular ducts on the pronotum; 3) abdominal calli absent.Recently, Xu et al. (2015) stated that some characters proposed by Leschen (2003) are unreliable for the subfamily distinction, for example: 1) pockets on the mentum, which are reduced or absent in Pharaxonotha; 2) cuticular glandular ducts of prothorax microtubate, only when present; 3) abdominal calli absent, which, in the dichotomus key of Leschen (2003), the alternative option is "usually present".These three characters therefore do not ensure that new taxa will be placed as Pharaxonothinae.It was therefore proposed to use a combination of two characters, i.e., the presence of a transverse occipital ridge and absence of abdominal calli, which occurs only in members of Pharaxonothinae.
More recently, Xu et al. (2015) and Skelley et al. (2017) were able to distinguish Cycadophila from other Pharaxonothinae using a combination of character states: 1) transverse occipital ridge present; 2) supraocular striae present; 3) presentation of a remnant of the submentalgular suture visible to variously depressed; 4) abdominal calli absent; 5) male genitalia with median lobe and tegmen twisted like a corkscrew, and spiculum gastrale asymmetrical; 6) wings with anal cell present.In this context, the specimens found in Tlachinola, Coacoatzintla belong to the Pharaxonothinae subfamily.However, some characters proposed by Xu et al. (2015) and Skelley et al. (2017), to distinguish Cycadophila from Pharaxonotha and other genera of Pharaxonothinae, are present in the specimens of both species described here; i.e., submentalgular area visible as depressed darkened area, often with row punctures and setae.We described the new species as belonging to Pharaxonotha since we consider that other characters used to distinguish the Cycadophila genus, such as male genitalia with median lobe and tegmen laterally flattened and slightly to strongly twisted (at least basally), will be only variation within the Pharaxonotha genus.Moreover, Cycadophila as defined by Xu et al. (2015) is only distributed in Asia, whereas Pharaxonotha is widely distributed in the Americas.More recently, Tang et al. (2018) mentioned a new genus associated with Ceratozamia, however it was undescribed in their study.

Key to the New World species of Pharaxonotha
(some characters in the key were based on Pakaluk 1988;Chaves and Genaro 2005;Franz and Skelley 2008).
Description.Body in dorsal view elongate to oval (Fig. 1A); length 4.1-6.0mm, width 1.68-2.42mm, greatest width near anterior 2/3 of elytra together, length/width ratio 2.39-2.53(N=10); in lateral view depressed (Fig. 1B), dorsally and ventrally slightly convex; color reddish-brown, head with darkest pigmentation, thorax (including pronotum and legs) and ventral intermediate, and elytra with lightest pigmentation, light reddish-brown and weakly transparent; sculpture uniformly and moderately densely punctulate on head and pronotum, although on head punctures are slightly thicker, on meso-and metaventrite punctures are coarser and thicker, moderately densely distributed; dorsal surface almost glabrous, but with yellowish distinguished setae moderately densely arranged on ventral surface and apex of pronotum, most notorious in apex of pronotum, base of mesoventrite, sternites, apex of tibiae, and tarsae.
Thorax.Pronotum (Fig. 2H) in dorsal view slightly transverse, length/width ratio 0.68-0.83(N=10), evenly convex, anterolateral edges weakly projected, angulate, not evenly rounded, posteriorly on each side without 1 narrow sulcus positioned at half distance between midline, but with a minute impression in the margin at the same position; posterior margin slightly arcuate, centrally projected; lateral edges straight to slightly arcuate, subparallel, with slightly elevated carina continuing to the posterior margin; anterior margin slightly arcuate, anterocentrally projected; in lateral view, hypomera almost trapezoidal, slightly convex and glabrate, with a projection at the posterior margin surrounding the procoxae, which is almost in contact with the prosternal process.Elytral epipleura almost glabrate, except in the subapical region where it presents yellowish setae; each elytron with two lateral patches of pseudopores, one at 1/4 and the other at 1/2 of the length of elytron (only visible on slides); with mesepisternum triangular; mesepimeron almost triangular; metanepisternum large, posteriorly slightly narrowed; metepimeron medium size (approx.1/2 the width of the metanepisternum), nearly entirely covered by elytra.Prosternum in ventral view nearly evenly convex; lateral margins anteriorly distinctly diverging along suture; anterior margin straight to laterally arcuate, crenulate, with row of long, anteriorly directed yellow setae; procoxal cavities separated by double distance of breadth of antennal funicle, laterally closed, although posteriorly open.Mesoventrite (Fig. 2I) short, at the same level as metaventrite (not inflected); anterior margin with a small impression on each side of midline (visible on slide) to receive the prosternal process; mesocoxal cavities laterally closed.Metaventrite (Fig. 2J) long (2.2× longer than mesoventrite), laterally convex, centrally slightly impressed, with midline suture extending along posterior 2/3, at posterior end between narrowly separated metacoxal cavities with small, rounded emargination.Metendosternite with lateral margins of stalk slightly diverging; lateral arms long and narrow, directed lateroventrally; dorsal furcal arms directed dorsally at a nearly 90° to lateral arms, apically slightly widened; anterior tendons separated from median Primero en línea point by nearly 1/7 of the distance towards base of furcal arms.
Abdomen.Venter in ventral view with 5 visible segments; anterior margin of the sternite III medially with distinct acute-triangular projection between metacoxal cavities, and anterolateral edges slightly projected; lateral margins arcuate-rounded; posterior margins slightly rounded to truncate, posteriorly converging; sternite III longer than IV, metasubcoxal lines absent; IV to VI similar in length; VII slightly longer than VI, posterior margin with row of short to fairly long, appressed, densely arranged yellow setae.Tergite VII with one patch of yellowish setae on each side of midline, posterior margin truncated with several rows of short yellowish setae.Pygidium (tergite VIII) in dorsal view trapezoidal, lateral margins almost straight, posterior margin slightly arcuate, with several rows of short yellowish setae; as long as ventral sternite VII (visible on slide), slightly convex, narrow.
Description -female.Similar to male (see description above); with exception of the pygidium with posterior margin less arcuate.
Sternite VIII (spiculum ventrale) present.Tergum IX (paraprocts) with oblique longitudinal separation, internal margins slightly more strongly sclerotized.Tergum X (epiprocts) and gonocoxites more or less triangular, posteriorly gradually narrowed, apices of gonocoxites laterally with small concave impression maintaining some setae; gonostyli short, narrow, posteriorly diverging and not visible broadened, with minute setae.Vulvar tube membranous, posteriorly expanded.Spermatheca (Fig. 2P) narrowed for half of the length, basal and apical half more or less equally broad; deflected by nearly 180°, C-shaped, apically convex, basally with a long point, and laterally with accessory gland.
Variation.Basically there are differences in size, a slightly lighter and more heterogeneous pigmentation in teneral specimens, and variation in the shape, depth, and color of the elytral punctures.
Description.Body in dorsal view elongate to oval (Fig. 3A); length 3.6-5.32mm, width 1.41-2.1 mm, greatest width around 2/3 that of elytra together, length:width ratio 2.4-2.74(N=10); in lateral view depressed (Fig. 3B), dorsally and ventrally slightly convex; color yellowish-brown, head and, in some specimens, pronotum with slightly darkest pigmentation, rest of body with lightest pigmentation, light yellowish-brown and weakly transparent; sculpture uniformly and moderately densely punctulate on head and pronotum, although on head punctures are slightly thicker, on meso-and metaventrite punctures are slightly coarser and thicker, but apparently more densely distributed on mesoventrite; dorsal surface almost glabrous except for the elytra which show some yellowish setae; moreover, with distinguished yellowish setae moderately densely arranged on ventral surface, apex of pronotum and elytra, most notorious on apex of pronotum, base of mesoventrite, sternites, tibiae, tarsae, and femur.
Thorax.Pronotum (Fig. 4H) in dorsal view slightly transverse, length:width ratio 0.62-0.77(N=10), evenly convex, anterolateral edges weakly projected, angulate, not evenly rounded, posteriorly on each side with 1 almost imperceptible sulcus trace positioned halfway between midline and outer margin, which finishes close to posterior margin in a small impression; posterior margin slightly arcuate, centrally projected; lateral edges straight to slightly arcuate, subparallel, with slightly elevated carina continuing to the posterior margin; anterior margin almost straight; in lateral view, hypomera is almost trapezoidal, slightly convex and glabrate, with a projection at posterior margin surrounding the procoxae, which is almost in contact with prosternal process.Elytral epipleura with scarce setae, except in the subapical region where dense yellowish setae are presented; each elytron with two lateral patches of pseudopores, one at 1/4 and the other at 1/2 of the length of elytra (only visible on slides); with mesepisternum triangular; mesepimeron almost triangular; metanepisternum large, posteriorly slightly narrowed; metepimeron medium size (approximately half of the width of the metanepisternum), nearly entirely covered by elytra.Prosternum in ventral view nearly evenly convex; lateral margins anteriorly distinctly diverging along suture; anterior margin straight to laterally arcuate, crenulate, with row of long, anteriorly directed yellow setae; procoxal cavities separated by double distance of breadth of antennal funicle, laterally closed, although posteriorly open.Mesoventrite (Fig. 4I) short, at the same level as metaventrite (not inflected); anterior margin with a small impression on each side of midline (visible on slide) to receive the prosternal process; mesocoxal cavities laterally closed.Metaventrite (Fig. 4J) long (2.3× longer than mesoventrite), laterally convex, centrally slightly impressed, with midline suture naucoridae.indd19 19/09/18 4:54 p.m.
extending along posterior 2/3, at posterior end between narrowly separated metacoxal cavities with small, rounded emargination.Metendosternite with lateral margins of stalk slightly diverging; lateral arms long and narrow, directed lateroventrally; dorsal furcal arms directed dorsally at a nearly 90° to lateral arms, apically slightly widened; anterior tendons separated from median point by nearly 1/2 of the distance towards base of furcal arms.
Scutellar shield, transverse, posterior margin rounded but converging in a small point in the middle.Elytron (Fig. 4N) in dorsal view elongate-oval, elytra together length / width ratio 1.70-1.82(N=10), greatest width at half; anterior margins nearly straight, with narrow anterior marginal line (cf.Chaves and Genaro 2005), angulate at midline; humeri small (not protruded), rounded; lateral margins slightly arcuate, subparallel along anterior 2/3, posteriorly slightly converging, more strongly converging along posterior 1/3; posterior margins subcontiguous; in lateral view slightly and evenly convex; 10 complete striae + 1 short scutellary striole (with 9-13 punctures) extending along anterior 1/5 near midline; striae I-VI narrower than intervals, not grooved, punctures coarser in striae I-III, VII-X, and punctures smooth in striae IV-VIII, subcircular, slightly irregularly spaced, intervals closer among striae VII-VIII and IX-X, with small setae in fine punctures located on intervals; striae not appearing obsolete along anterior and posterior 1/3.Wings as long as body or slightly longer than body, wing:body ratio 1.0-1.13(N=4), elongate to oval, length:width ratio 2.29-2.87(N=4), greatest width near central region; costal margin slightly sinuate, posterior margin slightly arcuate, with jugal area separated from anal region by a small V-shaped incision; all major veins present (compare with McHugh et al. 1997), but without anal cell (see Chaves and Genaro 2005); radial, medial and apical fields without evident maculations; macrosetae are visible at costal, anal and apical margins; microsetae are slightly visible on surface.
Abdomen.Venter in ventral view with 5 visible segments; anterior margin of the sternite III with distinct acute-triangular projection medially between metacoxal cavities, and anterolateral edges slightly projected; lateral margins arcuate-rounded, posterior margins slightly rounded to truncate, posteriorly converging; sternite III longer than IV, metasubcoxal lines absent; IV-VI similar in length; VII slightly longer than VI, posterior margin with row of short, appressed, densely arranged yellow setae.Tergite VII with one patch of yellowish setae on each side of midline.Pygidium (tergite VIII) in dorsal view trapezoidal, lateral margins slightly arcuate, posterior margin slightly arcuate, with several rows of short yellowish setae; as long as the sternite VII (visible on slide), slightly convex, narrow.
Description -female.Similar to male (see description above); with exception of the pygidium with posterior margin truncate.
Variation.Basically there are differences in size, a slightly lighter and more heterogeneous pigmentation in teneral specimens, and variation in the shape, depth, and color of the elytral punctures.Some specimens show yellow setae on submentum, and some a submental suture visible as a depressed darkened area.
Etymology.The species epithet makes reference to Ceratozamia tenuis, which is the cycad species where the new species of Pharaxonotha was collected.
Bionomics.Adults of Pharaxonotha tenuis were collected consistently on the pollen strobilus of C. tenuis, with more individuals present at the open pollen (Martínez-Domínguez et al. 2018).Larvae were found on decaying pollen strobilus and on the soil where the fragments had fallen.

DISCUSSION
In recent years, several species of pollinators from Asia, Neotropics, and North America have been collected from Cycas (Old World) and Zamia (New World) (Norstog et al. 1986;Tang 1987;Pakaluk 1988;Norstog et al. 1992;Tang et al. 1999).More recently, several species from Asia have been described or assigned to the new genus Cycadophila (Xu et al. 2015;Skelley et al. 2017), or some species of Pharaxonothinae were analyzed using 16S marker (Tang et al. 2018).However, some species of Pharaxonotha remain undescribed, indicating the need for further taxonomic study (Leschen 2003).Recently, Skelley et al. (2017) conducted a revision of Cycadophila; however, they recognized this genus based on morphology, where they included only some molecular characters as additional information, but the monophily was not tested.More recently (Tang et al. 2018) mentioned a new genus of Pharaxonothinae; however, they didn't describe or give morphological characters to distinguish this of Cycadophila and Pharaxonotha.The tree of maximum likelihood presented by Skelley et al. (2017) shows Cycadophila as sister clade of Pharaxonotha; however, it is weakly supported (bootstrap 37) and the subgenus C. (Strobilophila) Skelley, Xu and Tang was recovered as paraphyletic.At present, it is impossible to define the limits between Cycadophila, Pharaxonotha, and new genus of Pharaxonothinae since more taxa must be included through study.Several characters used by Skelley et al. (2017) to distinguish Cycadophila from other Pharaxonothinae are also present in Pharaxonotha; for example: the head surface with transverse occipital ridge (vertexal line), large eyes that encroach upon head ventrally, supraocular striae present, with a remnant of the submental gular suture visible to variously depressed, and the lack of abdominal calli.It is therefore necessary to describe more taxa, mainly those associated with Ceratozamia hosts, in order to conduct an extensive analysis that includes more taxa and another set of data (i.e.nuclear genes) to adequately test the monophily of this group.The genus Ceratozamia has been poorly studied; however, some researchers (Martínez-Domínguez et al. 2016, 2017a, b) have recently explored this genus.Here, we describe two new species of Pharaxonotha associated with C. tenuis, and we are being conservative in the use of Pharaxonotha concept used by Leschen (2003), since we consider that Cycadophlia will be a junior synonymy of Pharaxonotha when more of its taxa are described from other regions of Mexico.Finally, in the near future, the description and phylogenetic analysis of new species of Pharaxonotha will contribute to the knowledge of Pharaxonothinae, elucidating both systematic and biogeographical aspects.