Bioacoustics of Buenoa dilaticrus

Comments. Buenoa dilaticrus resembles B. tibialis Truxal, 1957 in general appearance, including the color pattern. According to Barbosa et al. (2010a), in both species the head and thorax are yellow, posterior region of hemelytra and abdomen dark brown; rostral prong originating laterally on proximal region, shorter than the third rostral segment and with its apex rounded; the fore femur lacking a stridulatory area; internal margin of fore tibia apically projected; and the hind femur sinuous. Buenoa dilaticrus can be distinguished by its tylus being strongly inflated and rounded ( Fig. 13 ); lateral expansion at the base of external margin of mid-tibia ( Fig. 16 ); hind femur with a line of crests on internal margin, each one with a short seta at apex; and left clasper with hook well developed apically (fig. 17). Buenoa tibialis possesses a tylus slightly inflated ( Fig. 50 ); mid-tibia enlarged at median region of external margin; hind femur sinuous with a line of short spines on inner surface; and left clasper with hook short and rounded apically ( Fig. 52 ). The expanded mid-tibia of B. dilaticrus is very similar to that of B. oreia Nieser, Melo, Pelli, De Campos Barbosa, 1997 , although the last species does not occur in the Amazon Region and is distinctly bigger, including its distinct rostral prong, among other features.

Comments. This species is very similar to B. tibialis Truxal, 1957 in many aspects, including the color pattern. Both species present head and thorax yellowish, posterior region of hemelytra and abdomen dark brown; the rostral prong originating laterally at proximal region, shorter than third rostral segment and with apex rounded; fore femur without stridulatory area; internal margin of fore tibia apically projected; and hind femur sinuous. Buenoa dilaticrus sp. nov. can be distinguished by its tylus strongly inflated and rounded; lateral expansion at the base of external margin of mid-tibia; hind femur with a line of crests on internal margin, each one with a short setae at apex; and left clasper with hook well developed apically. Buenoa tibialis possesses a tylus slightly inflated; lateral expansion at median region of external margin of mid-tibia; hind femur sinuous with a line of short spines at ventral surface; and left clasper with hook short and rounded apically.

Description of holotype . Measurements (male). Body length: 6.50; vertex: 0.22; synthlipsis: 0.05; head length: 0.60; head width: 1.76; pronotum length: 0.80; pronotum width: 1.84; scutellum length: 1.20; scutellum width: 1.60; length of fore femur: 1.02; width of fore femur: 0.30. Color. General color of hairs dark brown. Vertex yellowish. Frons reddish yellow. Tylus with a brown stain covering almost the surface; border between tylus and labrum yellowish. Labrum brown. First and second rostral segments light brown, third and fourth rostral segments dark brown; rostral prong yellow. Anterior half of pronotum yellow; posterior half stained of brown; ventrolateral surface of pronotum brown. Scutellum dark brown with a short yellowish area on anterior region. Metanotum yellow, with a triangular stain near the posterior margin. Ventral surface of thorax brown. Anterior half of hemelytra hyaline with costal 1. Nieser (1968) reported the occurrence of B. nitida Truxal in the state of Amazonas ( Brazil ), but lack information on locality. This occurrence was not cited in subsequent studies of Nieser. The record of this species in the Amazon Region was, therefore, not considered in the present work. margin brown; posterior half dark brown; membrane hyaline. Legs dark, predominantly brown. Abdomen dark brown; ventral carina yellowish. Head. Greatest width of head about eight times anterior width of vertex and distinctly narrower than greatest width of pronotum; head length on median line about three-fourths length of pronotum. Anterior margin of vertex continuous with the margin of eyes. Synthlipsis narrow, a little less than one-fourth of vertex width. Frons wide with parallel margins. Tylus strongly inflated and rounded. Rostral prong shorter than third rostral segment, with base originating laterally at proximal half of this segment and apex slightly rounded ( Fig. 1 ). Thorax. Pronotum unimpressed; lateral margins divergent; posterior margin slightly concave; median length about three-sevenths its greatest width. Scutellum large, with median length greater than that of pronotum. Fore legs robust. Fore femur narrowed at apex, with its length more than three times its width; without stridulatory area ( Fig. 2 ). Fore tibia with 17 stridulatory teeth, shorter at base and apex; anterior apex bluntly projected ( Fig. 3 ). Mid-tibia with lateral expansion near the base of lateral margin ( Fig. 4 ). Hind femur sinuous; internal margin with a line of 60 crests with a short setae on apex of each one. Abdomen. Left clasper with apex acute and turned anteriorly. Right clasper with apex rounded ( Fig. 5 ). Paratypes . Measurements (male/female). Body length: 6.20–6.60 / 6.75; vertex: 0.22–0.25 / 0.25; synthlipsis: 0.05–0.07 / 0.07; head length: 0.52–0.60 / 0.62-0.64; head width: 1.60–1.75 / 1.80–1.82; pronotum length: 0.70–0.85 / 0.76-0.80; pronotum width: 1.67–1.82 / 1.88–1.90; scutellum length: 1.08–1.20 / 1.08–1.12; scutellum width: 1.40–1.60 / 1.60; length of fore femur: 0.92–1.03; width of fore femur: 0,30. Colour and structural characteristics similar to holotype , except the female tylus with a brown spot; male and female scutellum yellow or dark brown with yellow area at anterior region. Greatest width of male head seven to eight times anterior width of vertex; female head seven to seven and one-half width of vertex. Male synthlipsis one-fifth to one-third of vertex width; female synthlipsis about one-third of vertex width. Head length of male at median line, seven to eight-tenths length of pronotum; head length of female, eight-tenths length of pronotum. Length of male pronotum at midline about three-sevenths to four-ninths its greatest width; female pronotum length about two-fifths its greatest width. Female embolium wide and well defined with a slightly lateral dilatation on median region of hemelytra. Male fore tibia with 17 to 20 stridulatory teeth. Internal margin of male hind femur sinuous with a line of 55 to 58 crests, each one bearing a short setae on apex; females with 58 crests.