The species in the genus Syvbula possess more elaborate courtship behavior than other Orthoptera. This fact is difficult to explain because other species living in similar situations possess very simple behavior. Pair formation is achieved through the attraction of females to stridulating males, or through reciprocal stridulating and approaching between males and females. Occasionally females attract males by singing spontaneously. The two Syrbula species live together in parts of Texas. Reproductive isolation is ensured and needless sexual interactions are prevented by call differences; i.e., females respond only to the songs of their own species. Elaborate courtship is omitted when pairs are formed through an exchange of calling signals. However, in the presence of sexually unreceptive females, males perform elaborate courtship behavior. The movements of appendages are mostly synchronous suggesting they are controlled by a single command from the brain; however, some asymmetry of movements exists (the appendages on the two sides of the body assume different positions and may be out of phase with one another) indicating a more complicated control system than exists in the European species, GomPhocerus rufus. Males assume a position nearly parallel to the female during courtship and the near appendages perform one set of movements and the far appendages a different set. Each side of the body can perform both sets of movements. Intermale rivalry takes several forms: stealing of females by non-calling or non-courting males, the production of male-identifying or male-spacing signals and, possibly, chorusing. The causes for the evolution of elaborate behavior are unknown. It may have evolved due to sexual selection or due to the fact that females of Syrbula require some special sort of priming before each mating. Selection for reproductive isolation does not usually seem to result in elaboration of courtship in grasshoppers. Sexual dimorphism is pronounced and its importance may lie in sexual or species recognition.