This species has the characteristic strongly slanted face of gomphocerine grasshoppers, giving the head a sharp, wedge-like profile. The body is elongate and narrow, with coloration typically ranging from gray-brown to dark brown, sometimes with faint longitudinal striping along the pronotum and abdomen. As the genus name suggests (Melanotettix = “dark grasshopper”), individuals often appear darker and more somber than many other slant-faced grasshoppers, which helps them blend into dry grasses and soil. Alert and quick to respond, M. dibelonius typically escapes by a short jump followed by direct flight. Males are presumed to use soft stridulatory songs for courtship, as is typical of slant-faced grasshoppers, though these sounds are subtle and rarely noticed by casual observers.