Venatorellus Mendes, Chamorro-Rengifo and Rafael

Mendes, Diego Matheus De Mello, Chamorro-Rengifo, Juliana & Rafael, José Albertino, 2016, A new genus of predatory katydids (Orthoptera: Tettigoniidae: Listroscelidinae) from the Amazonian Rainforest, Zootaxa 4162 (3), pp. 594-600 : 595-597

Venatorellus Mendes, Chamorro-Rengifo and Rafael gen. nov.

( Figs. 1–4 )

Type-species. Venatorellus viridipedes Mendes, Chamorro-Rengifo and Rafael sp. nov., here designated.

Etymology. The genus name is composed by the Latin word venator, which means “hunter”, and the suffix ellus, which is a diminutive. Therefore, Venatorellus means “little hunter”.

Diagnosis. This new genus differs from the remaining Listroscelidini in the following combination of features: face smooth or barely wrinkled, the wrinkles being linear and transversal; fastigium frontis and verticis narrow and rounded; mandibles symmetric; the basal portion of the tegmina is dark, devoid of a bright yellowish spot. Venatorellus gen. nov. differs from Listroscelis Serville in the coloration of the tegmina, which have the basal portion with a bright yellowish spot, ventral sclerite (VS) of the titillator shorter than the total width of the dorsal lobe, the two projected and free sclerites TS are closer at the base and shorter. In Cerberodon Perty the face is strongly wrinkled, brain-like. In Monocerophora Walker the fastigium frontis is acute and projected upwards with dorsal area black, pronotum with a transverse mark on the dorsum, and tegmina are devoid of a membranous and translucent mirror.

Description. Head. Eyes globose, located laterally, inserted at the level of the ventral margin of antennal sockets. Apex of antennal sockets in dorsal view shorter than half the length of eyes. Face very slender in frontal and lateral view. Vertex barely visible in frontal view; width six-tenths the length of the head. Frons subtriangular or oval, with a rounded projection at middle, where the defined ocellus is located. Face with surface smooth or slightly wrinkled. Mandibles with apex elongate and curved inwards, symmetric ( Figs. 1 C and 1F). Thorax. Pronotum with anterior and posterior margins straight or slightly concave ( Figs. 1 A and 2B). Prozona with a transverse furrow extending to the lateral lobes, not reaching the lower margin. Mesozona with a transverse furrow, extending to the lateral lobes reaching the lower margin. Metazona with a straight transverse furrow extending laterally to the lateral lobes, reaching the posterior margin. Lateral lobes with lower margin almost straight; posterior margin slightly oblique, with rounded corners and without sinus humeralis. Each sternite with two spines with rounded tips; prosternal spines comparatively slender; metasternal spines flattened or slender. Wings. Wings in both sexes fully developed. Tegmina without a bright yellowish spot at the base. Tegmina coriaceous, hind wings hyalines ( Figs. 2 A and 2B). Legs. Hind coxae with ventral margin usually bearing one basal and one distal spine, the tip of the spines can be acute or rounded. Legs slender. Hind femora with variable length. Fore- and mid femora with a wide longitudinal furrow along the ventral surface. All femora armed with long stout spines. Fore tibiae with surface close to spines similar to the remaining surface, and a small rounded pit dorsally, below and close to each tympanal opening. Mid tibiae with six ventral spines. Hind tibiae with several spines on the dorsal and ventral margins. Genicular lobes of all legs ending in an acute tip. Tympanal openings located at the dorsal surface of the tibiae, the width of each opening about one-sixth the length; ear region conspicuously inflated.

Male. Tegmina. Left tegmen devoid of veins delimitating mirror; membranous mirror only in right tegmen ( Figs. 2 A and 2B). Left and right stridulatory files well developed ( Figs. 2 C and 2D). Postabdomen. Tergite X unmodified, similar to the remaining tergites. Cerci with bent apex; tubercles and bristles covering the entire surface, except the tip ( Fig. 3 A). Epiproct rounded. Subgenital plate slightly emarginated ( Fig. 3 B). Paraprocts triangular and concealing the phallus. Phallus with the titillator composed by a transversal bridge which arises from the basal portion of the dorsal lobe, and with two outward projections with rounded tips ( Figs. 3 D and 3E).

Female. Postabdomen. Subgenital plate triangular, with base wider than the apical portion ( Fig. 3 C). Ovipositor slightly upcurved; upper valve about two times as wide as lower valve; apex of ovipositor acute ( Fig. 1 D).

Distribution. This genus was collected only in the Brazilian Rainforest, in Manaus, Amazonas.

Included species. This genus includes only the new species Venatorellus viridipedes sp. nov.

Figures

FIGURE 1. Habitus of Venatorellus viridipedes sp. nov. A— C: male (A) lateral view, (B) dorsal view, (C) frontal view. D – F female, (D) lateral view, (E) dorsal view, (F) frontal view.

FIGURE 2. Wings of Venatorellus viridipedes sp. nov.. (A) tegmina dorsal view, (B) hind wing in dorsal view, (C) left stridulatory file, and (D) right stridulatory file.

FIGURE 3. Terminalia and internal genitalia of Venatorellus viridipedes sp. nov.. (A) male cerci in dorsal view, (B) male subgenital plate in ventral view, (C) female subgenital plate in ventral view, (D) phallus in dorsal view, (E) phallus in ventral view. Abbreviations: TS: titillator sclerite; Lw. vl.: lower folds of ventral lobe; Up. vl.: upper folds of ventral lobe.

FIGURE 4. Live individuals of Venatorellus viridipedes sp. nov.. (A) adult female, (B) immature male, (C) male soon after molting into adult, (D) adult male being preyed by Tytius metuendus on tree trunk.