A new species of the sharpshooter genus Soosiulus (Insecta: Hemiptera: Cicadellidae: Cicadellini) from the Brazilian Amazon Forest, with notes on a putative complex of species

. Soosiulus belterrensis sp. nov. is described and illustrated from the Amazon Forest of the state of Pará, northern Brazil. Both the male and female terminalia are treated in detail, in addition to color features. With the addition of this new taxon, the diverse Neotropical genus Soosiulus Young, 1977 now comprises 28 species. The new species is the first one proposed for Soosiulus after the original generic description. It appears to be included in a complex with eleven other Soosiulus species, all of them sharing a very similar color pattern. Among the members of this putative complex, the aedeagus of S. belterrensis sp. nov. is most similar to those of S. hastatus Young, 1977 and S. ruber Young, 1977, due to the presence of a pair of conspicuous dorsoapical processes. However, in S. hastatus and S. ruber the aedeagus has also a retrorse ventroapical process originated from a lobe; both process and lobe are not present in the new species. In addition, the female sternite VII in S. hastatus and S. ruber is convex posteriorly, whereas it has a distinct median emargination in the new species.


INTRODUCTION
Cicadellinae (sharpshooter leafhoppers) includes currently about 2,400+ species in circa 330 genera (Wilson and Turner 2007, McKamey 2007, Bartlett et al. 2018). This subfamily is very diverse and includes taxa from all major zoogeographical regions, being exceedingly rich in the Neotropics (Young 1968, 1977, Mejdalani 1998. They are among the largest and most brightly colored of the leafhoppers (Wilson and Turner 2007). Among the three most diverse leafhopper subfamilies, viz., Deltocephalinae, Typhlocybinae, and Cicadellinae, the latter is certainly the one most thoroughly studied in Brazil. However, new Cicadellinae genera and species are still frequently discovered in the country's major biomes (Amazon Forest, Atlantic Forest, and Cerrado). All known members of the Cicadellinae are xylem-feeders (Young 1968), and some of them are vectors of the bacterium Xylella fastidiosa Wells et al., 1987, which causes diseases in various agricultural plants (Redak et al. 2004). Currently, two tribes are recognized within this subfamily, a New World Proconiini and a cosmopolitan Cicadellini (Young 1968, 1977, 1986, Mejdalani 1998, McKamey 2007. Soosiulus Young, 1977(type species: Poeciloscarta fabricii Metcalf, 1965) is a diverse Neotropical genus that comprises 27 species (McKamey 2007). Most of the known species were described by Young (1977) in his comprehensive and detailed taxonomic review of the New World Cicadellini. This genus, which is distributed from Costa Rica and Panama through the Amazon region in Brazil and to Peru and Bolivia, includes species that are red or orange, contrastingly marked with black (Young 1977, Wilson et al. 2009). Other genera that include species showing a similar color pattern are Ladoffa Young, 1977, Ramosulus Young, 1977, Poeciloscarta Stål, 1869, Aurigoniella Takiya, Mejdalani & Felix, 2001, Subrasaca Young, 1977, and Parasubrasaca Mejdalani & Cavichioli, 2013(Young 1977, Wilson et al. 2009, Cavichioli and Takiya 2010, Mejdalani and Cavichioli 2013. Soosiulus can be distinguished from these similar genera by the following combination of features (Young 1977): (1) crown with area between ocelli flattened or slightly concave, without a median fovea; (2) antennal ledges, in lateral view, with anterior margin rectilinear and oblique; (3) epistomal suture interrupted medially; (4) forewings convex apically, apical membranous area distinct; (5) male pygofer with fairly numerous macrosetae usually extending in a broad diagonal group from middle of disk posterodorsally to dorsoapical margin, without processes; (6) subgenital plates slender, triangular, not extending as far posteriorly as pygofer apex; (7) paraphyses present and usually paired and symmetrical (exception: S. fulgidus Young, 1977, in which they are reduced to a longitudinal bar-like sclerite located at the apex of connective).
In this paper, a new species of Soosiulus is described and illustrated from the Amazon Forest of Brazil (state of Pará). Both the male and female terminalia are treated in detail, in addition to color features. This is the first species described for the genus after the detailed revision published by Young (1977). The possible existence of a complex of species within Soosiulus is briefly discussed.

MATERIAL AND METHODS
We have been able to study a series of 19 specimens of the new species, including females and males, which were collected by means of the use of a light trap. These specimens have been deposited in the following institutions: Departamento de Entomologia, Museu Nacional, Universidade Federal do Rio de Janeiro (MNRJ, Rio de Janeiro), Coleção Entomológica Prof. José Alfredo P. Dutra, Departamento de Zoologia, Instituto de Biologia, Universidade Federal do Rio de Janeiro (DZRJ, Rio de Janeiro), and Coleção Entomológica Padre Jesus Santiago Moure, Departamento de Zoologia, Setor de Ciências Biológicas, Universidade Federal do Paraná (DZUP, Curitiba). Techniques for preparation of male and female terminalia structures followed Oman (1949) and Mejdalani (1998), respectively. Dissected terminalia parts were stored in small vials with glycerin and attached below the specimens, as suggested by Young & Beirne (1958). Structural terminology followed mainly Young (1968Young ( , 1977, except for the facial areas of the head (Hamilton 1981, Mejdalani 1993, 1998 and the female terminalia (Nielson 1965, Hill 1970. Use of the term gonoplac followed Mejdalani (1998). Photographs of the body in dorsal view, of the face, and of the female sternites VII and VIII were made using a digital camera attached to a Motic SMZ-171 stereomicroscope. Photographs of the ovipositor valvulae were taken with a digital camera attached to Nikon Eclipse E200 light microscope. Line drawings were prepared with the aid of a camera lucida attached to a Nikon SMZ1270 stereomicroscope.

TAXONOMY
Soosiulus belterrensis sp. nov. Diagnosis. Head ( Fig. 2) with pair of distinct black apical spots at transition crown-face. Aedeagal shaft (Fig. 7), in lateral view, slightly curved dorsally; its apex with pair of strong spiniform processes directed dorsally and almost reaching pygofer apex; without ventroapical lobe and without retrorse ventroapical process. Female sternite VII (Fig. 10), in ventral view, with posterior margin convex on each side of distinct median emargination.
Ground color of dorsum ( Fig. 1) mostly orange. Head ( Fig.  2) with pair of distinct apical spots at transition crown-face and large median basal spot including ocelli, black. Pronotum ( Fig. 1) with anterolateral portions brown; with median spot extending along anterior margin, with slender arm projected laterally behind each compound eye, and pair of semioval spots on posterior margin, black. Mesonotum (Fig. 1) mostly black, distal portion of scutellum brown to orange. Forewing ( Fig. 1) with spot on each humeral margin connected by narrow band along commissural margin to transcommissural large hastate marking in clavus, black; claval sulcus with black stripe, at corium side, from base to apical portion, narrowed or evanescent apically; apical membranous area translucent brown. Face ( Fig. 2) with frons brownish-yellow tinged with orange; remainder of face mostly pale yellow. Lateral and ventral portions of thorax pale yellow; legs pale yellow tinged with orange, foretibiae mostly orange.
Female. Color pattern and external form similar to those of male. Terminalia. Sternite VII (Fig. 10), in ventral view, elongate, slightly narrowed posteriorly; posterior margin convex on each side of distinct median emargination. Pygofer, in lateral view, well produced posteriorly; ventral margin slightly sinuous; apex narrowly rounded; macrosetae distributed mostly on posterior portion and extending anteriorly along ventral area, absent on basal portion of disk. "Internal" sternite VIII, in dorsal view, formed by pair of lateral outer sclerotized areas associated with sternite VII and pair of complex elongate sclerites (Fig. 11) located between valvifers I above ovipositor base; posterior portions of latter pair of sclerites rounded and strongly sclerotized. Valvifer I (Fig. 12), in lateral view, subrectangular; surface with scattered denticuli and pores. Valvula I, in ventral view, with basal portion expanded and forming projection directed inwardly; blade (Fig.  12), in lateral view, slightly curved ventrally along apical fourth; ventroapical portion slightly expanded; apex acute; dorsal sculptured area (Fig. 13) extending from basal portion to apex of blade, formed mostly by scale-like processes arranged in oblique lines, except basally ( Fig. 14) with irregular linear processes positioned more horizontally; ventral sculptured area (Fig. 13) restricted to apical portion, formed mostly by slender scale-like processes; blade surface, especially basal half (Fig. 14), with few small setae [trichoid sensilla] and many pores located below or adjacent to ramus, basiventral surface with distinct group of denticuli; ventral interlocking device distinct, located on basal half of blade. Valvifer II (Fig. 18), in lateral view, somewhat pentagonal; inferior half with distinct group of about 20 robust setae (Fig. 19) near articulation point; denticuli and pores also present. Valvula II (Fig. 15), in lateral view, moderately expanded beyond basal curvature; blade slightly curved ventrally; preapical prominence ( Fig. 17) distinct, obtuse; apex (Fig. 17) obtuse; dorsal margin with about 35 well defined, mostly subtriangular teeth (Figs 16-17), with distinct small space between them; denticles distributed on teeth and on dorsal and ventral apical portions of blade, except on apex (ventral dentate apical portion much longer than dorsal portion); valvula with ducts (Figs 16-17) extending towards teeth and apex (number of ducts terminating inside teeth varying from zero to two); basal half of valvula with isolated pores. Gonoplac (Fig. 18) of the usual Cicadellinae type: in lateral view, blade extending slightly beyond pygofer apex; distal half distinctly expanded, slightly narrowed apically; apex obtuse; surface with many denticuli, pores, and setae on apical portion and extending anteriorly along ventral margin.
Etymology. The name of the new species refers to the type locality, municipality of Belterra, in the state of Pará.

DISCUSSION
The new taxon apparently belongs to a group that includes eleven other Soosiulus species; all of them share a very similar dorsal color pattern, including similarly located black markings on an orange background (Fig. 1). Perhaps, these species, which can be distinguished from one another mainly by the structures of the male terminalia, form a complex of closely related forms within the genus (see digital images in Wilson et al. 2009), viz., S. azatus Young, 1977, S. configuratus (Walker, 1858, S. decoris Young, 1977, S. fabricii (Metcalf, 1965) (type species), S. falcifer Young, 1977, S. hastatus Young, 1977, S. interpolis Young, 1977, S. lunatus Young, 1977, S. ruber Young, 1977, S. sermunculus (Melichar, 1932, and S. umaritubanus Young, 1977. Among the members of this putative group, the aedeagus of the new species (Fig. 7) is more similar to those of S. hastatus and S. ruber, due to the presence of the pair of dorsoapical processes. However, in S. hastatus and S. ruber the aedeagus has also a retrorse ventroapical process originated from a lobe (Young 1977); both process and lobe are not present in S. belterrensis sp. nov. (Fig. 7). Among these three species, the dorsoapical aedeagal processes of S. hastatus are the longest and those of S. ruber, the shortest. The female sternite VII in S. hastatus and S. ruber is convex posteriorly (Young 1977), whereas it has a distinct median emargination in the new species (Fig. 10).