Synonyms and other taxonomic changes
Acridium rubiginosum (Harris ex Scudder, 1862
Schistocerca rubiginosa (Harris ex Scudder) Morse, 1904
Schistocerca alutacea rubiginosa (Harris ex Scudder) Morse, 1920
Identification
Difficult to tell from closely related S. alutacea, but a few things are fairly constant. The tegmina (front wings) are usually speckled or spotted (sometimes nearly plain, but faint spotting usually still visible), and usually there is no pale stripe on top of these (when folded) and the pronotum. If the stripe is there, it is usually not well-developed, and not very contrasting. In S. alutacea the stripe is nearly always there and usually strongly contrasting, while the tegmina are usually plain or only very faintly spotted. The cercus of the males of S. rubiginosa are considerably smaller, which makes males easier to identify than females. The head averages larger in proportion to the thorax, but this is a subtle difference. Shades of reddish brown are the most common coloring, with other hues such as various browns and greys also seen (especially in the far south). Shades of green are very rare.
S. lineata is very similar too, and in the Midwest and northeast the two might occur together (or blend with one-another?). S. lineata also differs in having larger male cerci, and has distinctly thickened front and middle femora in males. In S. lineata the pale stripe is often present and constrasting, but it varies and may be absent. The coloration of S. lineata is highly varied, and in the area of overlap or contact with S. rubiginosa it is often colored vary much the same, and some females may be very difficult to identify. Also, S. lineata can be greenish (though most often it is tan to yellowish brown), while apparently green does not occur in S. rubiginosa.
S. damnifica can be colored similarly to S. rubiginosa, but is otherwise different enough to usually be easily distinguished even in photos. S. damnifica is usually plainer and more "smooth" looking in coloring, not spotted (or at most faintly blotched). There may be a pale mid-dorsal stripe on the pronotum (though usually not very contrasting). The top of the folded wings are usually paler than the sides. It averages smaller, has the wings usually proportionately shorter, has much shorter (and rather thickish) antennae, has different male genitalia, and has the pronotum higher on top and more "roof-shaped". The head is more "squared" at the vertex (forhead), and tends to appear smaller in proportion to the rest of the body.
Range
Primarily Gulf and Atlantic Coastal Plain from Texas to North Carolina. There are records northward along the coast to Connecticut, and inland onto the Peidmont and through northern Mississippi to Tennessee. There are published records (which probably need verification) further north into the Midwest, which may all actually have been referable to S. lineata as now defined. S. rubiginosa shares most of its distribution with S. alutacea, but favors more open and xeric, usually sandy habitats.
Habitat
Most often found in sandy open weedy or prairie-like areas, or along beaches and on sand dunes.
Life Cycle
Overwinters as eggs, hatching in spring, with adults mostly seen from June to October, sometimes with some surviving later if weather allows. Adult season is more extended and less well-defined in Peninsular Florida.
Remarks
This is a member of the "Alutacea" Group, which includes several very closely related populations that are treated by some authors all as subspecies of S. alutacea, while most authors treat most as distinct species. S. rubiginosa is very similar and closely related to S. alutacea, and has been treated as a subspecies.
However, there is some evidence that S. rubiginosa is perhaps more closely related to S. lineata and that the two may intergrade where they meet or overlap distributions. For the most part the two species displace one-another geographically, but in the areas of contact many specimens (females in particular) may not be identifiable as one or the other. [see further notes under Schisticerca lineata "Eastern Coastal segregate".]
