The genus Cuernavaca (Hemiptera: Dictyopharidae), associated with Pontederiaceae in South America, with redescription and new records of C. inexacta (Walker)

. The aim of this paper is to shed light on the boundaries of two sympatric species of Cuernavaca, C. inexacta and C. longula, to enable further ecological studies. Species in this genus are associated with water hyacinths in wetlands of Northeastern Argentina (Paraná-Paraguay waterway system) and the Peruvian Amazon. This work lists new host records for Cuernavaca, which include Pontederia crassipes, P. cordata, P. subovata and P. rotundifolia (Pontederiaceae). A redescription for C. inexacta with new diagnostic genitalic features is also provided, as well as an updated identification key and a distribution map. The genus is distributed throughout Central and South America, reaching north and central Argentina in its southernmost distribution.

Dictyopharids are known to feed predominantly on a variety of dicotyledonous herbs, with a few species recorded on monocots (Bourgoin, 2016;Denno & Perfect, 1994;Wilson et al., 1994;Wilson & O'Brien, 1987).This group also include a few species that are agricultural pests of significant economic importance (Bourgoin, 2016;Krstić et al., 2016).Information on host plant associations and the effects caused by the herbivory of Cuernavaca species is fragmented (Hernández et al., 2011a, b;Maes & O'Brien, 1988;Sacco et al., 2013).In South America, Cuernavaca inexacta was regarded by Bennett & Zwolfer, 1968 as a potential biocontrol agent of the water hyacinth Pontederia crassipes Martius (Pontederiaceae) [ex Eichhornia crassipes (Mart.)Solms-Laub.(Pellegrini et al., 2018)].Our taxonomic assessment of Cuernavaca associated with water hyacinths revealed that C. longula coexist with other related species from the upper Amazon River (Remes Lenicov & Hernández, 2010;Remes Lenicov et al., 2012).These species are sympatric in part of their distribution, and should be properly distinguished among themselves so their potential as biocontrol agents can be more thoroughly explored.Therefore the aim of this paper is to redescribe C. inexacta in detail, incorporating new diagnostic characters of the male and female genitalia, and updating a key to the species of Cuernavaca, as well as distribution and host plant associations.

Examined specimens
The taxonomic assessment presented here was mainly based on primary types and secondary types, but also included specimens listed in the original descriptions or identified by renowned specialists in the field.Additional specimens were specifically collected in wetlands of Northeastern Argentina (in the Paraná and Paraguay rivers basin) and the Peruvian Amazon.We used a sweeping net or manual techniques on natural mats of free-floating aquatic species: P. crassipes, P. cordata L., P. subovata (Seub.)Lowden and P. rotundifolia L. Specimens studied in the course of this work are deposited in the following institutions, which are subsequently referred to by their acronyms: British Museum of Natural History (BMNH), London, UK; Muséum National d'Histoire Naturelle (MNHN), Paris, France and Museo de Ciencias Naturales de La Plata (MLPA), Argentina.

Morphological studies
Specimens were killed in 95% ethyl ether to preserve their coloration.Genital segments were dissected and cleared in 10% KOH at room temperature for ca.24-48 hours, rinsed and immersed in distilled water, then trans-ferred to 10% glycerol microvials for long-term storage.Dissections from the male and female genitalia were fixed in Faure's medium for morphological analysis and illustration, according the procedures outlines in Remes Lenicov & Hernández (2010).Observations, measurements and pictures were made using a stereomicroscope LEICA EZ5 and a RRID 18 HD digital camera.Digital images were assembled using Combine ZM open software (Hadley, 2011) and improved with the Adobe Photoshop CS5 software.
Morphological terminology and measurements follow Song et al. (2016a, b) for the majority of characters, Bourgoin et al. (2015) for tegmina venation, and Bourgoin (1993) for female genitalia.Reported measurements (median and range) were taken from 10 specimens of each sex and are given in millimeters.

Abbreviations on each measurement are as follows:
L. = total length (from apex of head to apex of forewings); B.L. = body length (from apex of head to tip of abdomen); W.L. = forewing length.One additional measurement is relative; length: width ratio (L:W) of the vertex, which was measured along the vertex midline and near its mid-length respectively.
A distribution map of Cuernavaca species was assembled with QGIS 3.02 using literature records and from the material examined; new distributional records are marked with an asterisk (*).

Cuernavaca Kirkaldy, 1913
Morphological and phylogenetic studies given by Emeljanov, 2011 andSong et al., 2018, respectively, show that Cuernavaca and Taosa are closely related.Cuernavaca may be separated from the latter by the following characters: head relatively short, frons broad not visible in dorsal view, tegmina membranous with a second rank of postnodal closed cell on membrane; female with ovipositor elongate, anterior connective lamina of gonapophysis VIII with 12 or more small, longitudinally arranged teeth, gonoplacs extremely elongate and narrow with with a bunch of long setae near apex on ventral lobe.
The three species presently included in this genus can be distinguished by the following key.

Key to species of Cuernavaca (Modified from Remes Lenicov & Hernández, 2010: 334)
1. Uniformly green with a pair of small dark spots on each side of mesonotum; male with gonostyles shorter than anal segment, suboval; females with strongly elongated anal segment, 5 times its width; long and straight gonapophyses VIII with a row of strong
Cuernavaca longula: It was described as the first Dictyopharinae species associated to P. crassipes from Argentina and studied as a candidate of biocontrol of this weed because of its narrow host range in the Pontederia spp.(Pontederiaceae) (Hernández et al., 2011a;Remes Lenicov & Hernández, 2010).

Cuernavaca herbida:
The only known host plant association is with Liberian coffee in Trinidad (Fennah, 1945).

Field observations
Representatives of the genus collected on P. crassipes in several sites in Peru and Argentina, show that C. inexacta and C. longula occupy similar ecological habitats, although C. inexacta was more abundant in the wetlands of the Peruvian Amazon than in the Paraná-Paraguay fluvial wetlands system.The Argentine wetlands drain into the Rio de La Plata river basin that is the southern border of the native range of the Pontederiaceae species and also of the Cuernavaca species.Taosa paraherbida Muir, 1931: 474, synonymized by Fennah, 1947: 9. Taosa (Cuernavaca) paraherbida Muir, 1931, according to Metcalf, 1946: 110.Taosa inexacta (Walker, 1858) restored by Fennah, 1947: 9. Cuernavaca inexacta (Walker, 1858) according to Emeljanov, 2011Emeljanov, : 1123;;Song et al., 2018: 13.
Emended diagnosis: General color green, slightly tinged reddish brown band overlying submedian frontal carina and base of ocelli.Tegmina and hindwings clear hyaline with green veins; pterostigma opaque yellowish.Body elongate; head with narrow vertex, slightly longer than wide across base, projected for more than half its length in front of eyes, median carina evanescent in apical half, transverse carina anteriorly bounding well-defined trigones, separated from preocular areas by slightly sinuous carina, sharp apices distant from midline; frons long, lateral margins slightly parallel in basal half, barely expanded in apical third; rostrum extending past basal third of hind femora in repose.
Male: Anal segment ventrally covering apex of gonostyles; gonostyles slender, longer than wide, narrowing at base in ventral view, upper margin slightly angular on basal half and gradually narrowing to the apex, with a distinctive long straight process dorso cephalad directed, apically obtuse, and a small ventro caudad curved hook-like process near sub-middle on the outer edge, in lateral view; aedeagus ending in a pair of long sinuous ventro-apical curved spinose processes dorsocaudally directed; phallobase tubular with a pair of slender and apically lanceolated endosomal processes emerging abruptly cephalad in their apical fourth.Segment X distinctly elongate, anal style far beyond apical ventral margin of segment X.
Female: Anal segment relatively short, just above the ovipositor; ovipositor short and strong; gonapophyses VIII (first valvulae) strong, slightly curving upward to apex, anterior connective lamina with about 24 uneven teeth decreasing in size toward base arranged in double row running subparallel in the dorsal margin.Gonoplacs (third valvulae) slightly elongated, the ventral lobe with a narrow densely hairy area along lower margin and a tuft of short stout hairs at apex.Segment X oval to elongate; anal style far beyond apical ventral margin of segment X. Female ectodermal genital ducts ditrysian, surrounding area of copula poris distinguishably colored.

Redescription
Body (Fig. 1A-C): Ground color uniformly green, with slightly tinged reddish brown bands overline submedian frontal carina and around ocelli.Tegmina and wings clear hyaline with green veins; pterostigma opaque yellowish.
Head: Vertex narrow in dorsal view, little longer than broad across base (1.1:1), apical margin broadly angulate, projecting in front of eyes by more than half its sally bounding the well-defined subtriangular trigones, separated from preocular areas by a slightly sinuous carina, sharp apices distant from the mid line.Frons relatively short, in the middle a little longer than wide at maximum width (1.3:1), linear, with lateral margins slightly parallel in the basal half, barely expanded in the apical third, carinae distinct, without carina between apex of lateral and intermediate carinae, the median complete and very feeble, the intermediates subparallel, nearly straight, weakly ridged, evanescent next to frontoclypeal suture, laterals strongly ridged; apical margin deeply excavated and inverted V-shaped.Clypeus longer than wide at base (2.1:1), surpassing apex of fore coxae, laterals and median carina distinctly elevated, median extended to apex (Fig. 1C).Labrum free, elongate; rostrum relatively long, surpassing basal third of hind femora, basal segment longer than apical (1.3:1) reaching apices of hind coxae.Compound eyes long oval.Ocelli present.
Thorax: Pronotum wider than head (1.3:1), shorter than vertex at midline (0.5:1); carinae distinctly ridged, median carina percurrent, intermediate carinae distinct in basal third to half, curved closely behind the eyes, with a prominent slightly curved downwards carinae on paranotal lobes not reaching rear edge; anterolateral angles rounded, anterior central margin arcuately convex, posterior margin deeply concave.Mesonotum medially more than six times the length of the pronotum, carinae distinct, extinct at the scutellum, the laterals slightly divergent, feebly incurved basally not reaching median carina; tegmina membranous extending beyond the abdomen, with ratio length to maximum width 3:1; hyperpterous in R, MP and CuA., with a second rank of postnodal closed cells after the nodal cells; pterostigma narrow three-celled.Hind tibiae with 4 lateral black-tipped spines and 8 apical black-tipped teeth; hind tarsomeres I as long as II and III together, tarsomere I and II with seven black-tipped apical teeth, respectively (Fig. 1D).
Male genitalia (Fig. 1E): Pygofer in lateral view distinctly longer ventrally than dorsally (4:1), more than twice ventral width; caudal margins rounded, slightly expanded ventrally; dorsal margin straightly excavated to accommodate segment X; ventral margin narrowly truncate.Gonostyles relatively large, slender; in lateral view with base narrow, strongly expanded in the middle and gradually narrowed towards rounded blunt apex; upper margin slightly angular at basal half, with a long lightly compressed straight hook-like process forward directed, apically obtuse; outer upper edge with a small ventro caudad curved spine near sub-middle.Aedeagus with phalloteca tubular, slightly sclerotized at base and laterally, the remainder membranous with pair of inflatable membranous lobes, ending in slender ventro-apical spinose processes dorso-caudally directed and downward recurved at apex; phallobase tubular with a pair of slender and apically lanceolate endosomal processes extending posteriorly below theca and folding abruptly cephalad in their apical fourth.In lateral view, ventro-apical spinose processes of aedeagus reaching apex of gonostyles and ventrocaudad angle of segment X at rest.Connective slender, elongate and slightly sclerotized, extending obliqually from the base of aedeagus to the base of by: Segment X as long as the length of style in lateral view; in dorsal aspect distinctly elongate, distal portion deeply medially emarginated, with ratio of length to width 2.5:1; in lateral view dorsal and ventral margins straight, the latter slightly longer in lateral view (1.1:1); apex obliquely truncate; anal style (Epr and Ppr) relatively short extended more than the half of its length beyond apical ventral margin.
Female (Fig. 1B): Similar to male in body morphology and coloration., G): Short and strong ovipositor; anal segment relatively short, reaching apex of ovipositor at rest.Gonocoxa VIII (1 st valvifer) triangular, vertically placed, gonapophyses VIII (1 st valvulae) subelliptical in lateral view, dorsal border smoothly and slightly curved, ventral border slightly convex to dorsum, both dorsal and ventral margins narrowing sharply in the apical half, slightly curving upward to apex; anterior connective lamina with subparallel double rows of unequal teeth on dorsal margin, each one consisting of about 10 to 11 sharp teeth, almost same-sized, lightly descending in size toward base.Gonapophyses IX, elongate and narrow.Gonoplacs (3 rd valvulae) with both lobes subequal in length, as long as anal segment, subparallel sided, ventral lobe rounded at apex, with lower margin convex strongly curving upward to apex, with a densely hairy area along lower edge in apical half and a tuft of rigid hairs at tip; dorsal lobe slender truncate at apex, strongly reflected inward.Segment X longish ovate, distal portion deeply medially emarginated, with ratio of length to width 2:1; in lateral view dorsal and ventral margins straight, the latter slightly longer in lateral view (1.1:1); apex slightly truncate; anal style (Epr and Ppr) relatively short extended more than half of its length beyond apical ventral margin.Ectodermal genital ducts ditrysian; copulaporis area darkish colored, corresponding to the inner esclerotized vaginal plates, visible through translucent skin, more evident in cleared specimens.

Taxonomic remarks
Cuernavaca inexacta differs from its congeners in its coloration pattern and head traits.The most distinctive features of the male genitalia are the combination of the angular profile of gonostyle, the longest and slender processes in the aedeagal complex and the endosomal processes.Whereas in female, the distinctive feature is the numerous teeth arranged in two subequal and sub-parallel rows on gonapophyses VIII.
Cuernavaca inexacta can be easily distinguished from the sympatric C. longula, known to occur in the same habitats and feed on the resources in several areas of South America, by the smaller size, the reddish brown coloration on the base of frons and around base of ocelli, the longer vertex, the frons not so strongly expanded near apex, the gonostyles wider at middle in lateral view with straight and forward directed hook-like process, and the more slender, longer and different shaped adeagal and endosomal processes in male, and the female by the distinctly shorter anal segment and ovipositor, the greater number of teeth lying in two rows on the anterior connective lamina of gonapophyses VIII and the darkish coloration on the copulaporis area.
Female genitalia of Cuernavaca inexacta is redescribed and redefined based on examination of the Holotype of Dictyophara inexacta Walker (Figs. 2A, B), the paratype female of Taosa paraherbida Muir (specimen designed as residual type by Fennah, 1947: 9) (Figs.2C, D), and 1 female of Taosa inexacta (Walker) from Guyarmare, Trinidad, Ghauri det.(Figs.2E, F) (all in BMNH).We observed that the anterior connective lamina of the gonapophyses VIII have two subequal and subparallel rows of teeth dorsally, each with 10 to 11 sharp denticle.These features contrast with those erroneously described and illustrated by Fennah (1945) for T. paraherbida Muir as follow: "First valvulae narrow, sinuate, with a row of eight stout, short, triangular teeth on dorsal margin, with a point at apex".In the remaining features specimens match the original description in every detail; probably the double row of denticles might not have been observed by the author from a side view (p.464, pl. 12, fig.306).
Examination of one male specimen of Taosa paraherbida bearing Muir's identifcation label from Colombia (BMNH) (Figs.2G, H) as well as those field collected specimens from Peru and Argentina, allowed us to provide a more complete description.We also noticed very little intraspecific variation in color and morphology among the adults in both sexes.

Distribution
According to previously published records and voucher specimens from the BMNH, MNHN and MLPA, the three species of Cuernavaca are distributed over Central and South America, reaching north and central Argentina in the southernmost distribution (Fig. 3).