160 U.S. NATIONAL MUSEUM BULLETIN 261 



36. Genus ACROBELUS Stal 

 Figures 149, 150 

 Acrobelus St5,l, 1869a:60. Type-species: Tettigonia reflexus Signoret, new name 

 {= Rhaphirrhinus attenuatus Walker), by monotypy. 



Length of male 14-16 mm. 



Head elongate and triangular, the apex produced into a rather broad 

 process which is directed dorsally and anteriorly, median length in- 

 cluding process much greater than transocular width, with a narrow 

 median fovea extending full length of crown and process; antennal 

 ledges in lateral aspect each with a longitudinal fovea, anterior margin 

 steeply declivous; clypeus convex except apically, where it is concave 

 on lower portion of process, muscle impressions indistinct but their 

 locations marked by transverse groups of fine setae; other characters 

 as in Deselvana. 



Thorax with pronotal disc punctate except narrow anterior sub- 

 marginal portion, with short setae, scutellum indistinctly transversely 

 striate on posterior half; otherwise as in Deselvana. Forewing with 

 membrane including only inner apical cell, veins distinct, not elevated, 

 texture coriaceous, with at least the clavus punctate, with four apical 

 cells, the relative position of bases of third and fourth variable, without 

 an anteapical plexus on corium, without or with only one or two 

 anteapical veins to costal margin. Hindwing as in Deselvana. Hindlegs 

 with femoral setal formula 2:1:0; first tarsomere with length less than 

 combined length of second and third. 



Male genitalia: Pygofer well produced, the apex broadly rounded, 

 with a few microsetae dispersed generally over disc, or limited to 

 anteapical region, with a group of submarginal and marginal apical 

 macrosetae, without processes. Plates not fused, extending as far 

 posteriorly as apex of pygofer, slender and elongate, roimded apically, 

 each with a number of dispersed microsetae. Style extending posteriorly 

 much further than apex of connective, with distinct preapical lobe, 

 truncate or not at apex. Connective short, Y-shaped, with a slight 

 median keel. Aedeagus symmetrical, shaft short, curved strongly 

 posteriorly and dorsally, with or without processes. Paraphyses present, 

 paired, closely associated with base of aedeagus, with length variable 

 interspecifically. 



Female abdominal sternum VII not strongly produced, posterior 

 margin almost rectilinear, slightly concave on both sides of middle 

 (female of ^. rejlexus (Signoret) unknown). 



Specimens of Acrobelus are not very common in collections. The genus 

 is known from central and northern South America; the t>^e species has 

 been seen from Costa Rica and Panama. Acrobelus resembles Rhaphir- 

 rhinus in the aedeagal structure, in the produced head, and in a number 



