Genus Tigrosa

4 species transferred from Hogna & one from Allocosa.

Author of the name: Brady. Year first published: 2012.

The generic name is derived from the tiger because of the fierce nature of the species found in Tigrosa and in recognition of the stripes on the dorsal surface of the body and contrasting dark and light markings on the legs of most species. According to Don Cameron (2005) the genus name Lycosa means "fierce like a wolf"; therefore, Tigrosa can be freely translated as "fierce like a tiger."(1)

5 species in BugGuide's range (North America north of Mexico).

Body length (legs excluded) ranges from 10 to 31 millimeters. Tigrosa aspersa & T. grandis have the largest average body lengths of the genus, while T. annexa has the smallest.(1)

For Tigrosa spp., the dorsal color pattern on the carapace is important in telling the species apart, as is the body length, and the coloration of the venter (underside), though most important always remains the shape of the internal genitalia (spermathecae).

For females:

T. annexa - smallest species in the genus; venter is all pale yellow, except for two dark marks in center of the sternum and a black spot around the epigynum; carapace has two yellow dashes flanking the median stripe in the cephalic region.(1)

T. aspersa - largest species in the genus; ventral side of coxae all black, venter of abdomen orangish with scattered black spots and sometimes dark brown stripe down center; carapace with thin yellow stripe beginning at AME row and ending at PLE row (i.e. median stripe restricted to eye region only, or at least only that part of the band is bright/distinct); femora sometimes with 3 or 4 faint dark rings.(2)(1)

T. georgicola - venter of abdomen with three central dark stripes originating at the epigastric furrow and converging at base of spinnerets (much darker-looking than T. helluo); median stripe on carapace extends from the eye region all the way across to the posterior declivity; sometimes with 3 dark bands on dorsal surfaces of femora III and IV.(1)

T. grandis - 2nd largest species in genus; median band extends across entire carapace (from eye region to posterior declivity)- editor's note: this description of the median carapace stripe may be based on preserved specimens as examples of this species we have on BugGuide have a broken median carapace stripe with the anterior half being similar to aspersa; abdominal venter is light brown in center with dark brown spots on lateral areas.(1)

T. helluo - venter is spotted, coxae suffused with black; sternum reddish-brown suffused with black and with indistinct pale median band; median band on carapace extends full length, but does not have the short and distinct pale dashes behind the AME on each side of median stripe(2)(1)

For some detailed info on Tigrosa and Trochosa ID see the discussion here:

See Brady 2012(1) for maps.

T. annexa - has been found along the Atlantic coast from Delaware south to Big Pine Key, Florida, and westward from southern Ohio to the southern tip of Texas.(1)

T. aspersa - Ontario and Massachusetts in the northeast, southward along the eastern seaboard to North Carolina, and then westward to Kentucky and Tennessee, and in the Midwest from Michigan to Iowa, and then southward to Missouri and Arkansas.(1)

T. georgicola - widely distributed in the southeastern USA.(1)

T. grandis - has been found from eastern Kansas southwestward to Nevada and northwestward to Montana (occurs primarily west of the 100th meridian).(1)

T. helluo - New England and adjacent Canada south to Florida and west to the Rockies.(3) NM(4)(5)

Brady, Allen R., 2012. Nearctic species of the new genus Tigrosa (Araneae: Lycosidae). Journal of Arachnology 40(2):182-208.(1)