Bioacoustics of Tibicinoides

Redescription: Body size is highly variable with both inter and intra-specific variation. Head: The width of the head and eyes is equal to subequal that of the apical pronotal margin. The clypeus is variably pronounced. The center of the vertex has a deeply sulcate epicranial suture. Thorax : The pronotal margins are subquadrate to apically constricted with a longitudinal sulcus of varying depth running down the center. Two bilateral fissures run inwards towards the center of the pronotum at an anterior-posterior angle. The humeral and apical angles of the pronotum are distinct or not. The cruciform elevation is located directly anterior to the hind margin of the mesonotum. The anterior lateral sides of the mesonotum show vestigial stridulatory grooves in both sexes. The metanotum is clearly visible. Most species have the head, pronotum, and mesonotum variably black, brown, and yellow, but with a distinct set of four markings arranged in a trapezoid directly anterior to the cruciform elevation. Wings : Both fore and hind wings are hyaline, and the basal membranes are variable in color but typically orange. The fore wing length is 2.4–2.9 times the width, with 8 apical cells. The trapezoidal-shaped radial cell reaches the costal node situated halfway along the length of the costa. The ratio of apical cell to ulnar cell length is subequal in most species but 2: 1 in the species of Tibicinoides prior to its revision. The hind wing has 6 apical cells with a typical branched cubitus anterior (CuA) vein ( Fig. 3A ). The wing venation color is variable both within and among species with the base of the wings strongly infuscated or not. Legs : Metacoxa with a meracanthus with a distinct triangular shape, typically as long or longer than the coxa. All tibiae are often heavily setose but only the metatibiae have spines. Abdomen : In males the timbals are completely exposed with the timbal membrane having two long and two short ribs ( Fig. 3C ). The majority of female Tibicinoides show a distinct vertical gap between tergite VII and tergite VIII, giving them a hump-backed appearance ( Fig. 3E ), and epipleurite VII is usually subequal in length to epipleurite VI. Tergite VII is angled slightly inward posteriorly, particularly towards the base, causing this appearance. The abdominal sternites can be heavily setose or not, with intra-specific variation in this regard. Male Genitalia : Sternite VII in males is variably shaped, covering base of sternite VIII. Sternite VIII extends parallel to the length of the body, partially housing the uncus and aedeagus. The uncus is generally straight in the lateral aspect and curves at the tip, forming the characteristic hook of the genus ( Fig. 3B ). The aedeagus is variable but is often a species-specific shape and is attached to the ventral surface of the uncus. Female Genitalia : Sternite VII is variably excavated on its posterior margin, forming a primary notch with a secondary notch in the center of the primary ( Fig. 3D ). Both excavations are rounded in their entirety, forming no distinct angles between the primary and secondary notch (if clear). The sides of sternite VII form rounded apical prongs that vary in shape. Both traits are often species-specific.