Melanoplus discolor (Scudder, 1878)

Hill, JoVonn G., 2023, Diversification deep in the heart of Texas: seven new grasshopper species and establishment of the Melanoplus discolor species group (Orthoptera, Acrididae, Melanoplinae), ZooKeys 1165, pp. 101-136 : 101

Melanoplus discolor (Scudder, 1878)

Figs 2B , 3B , 4B , 5A-J , 14 , 15

Pezotettix discolor Scudder, S.H. 1878. Proc. Boston Soc. Nat. Hist. 20: 81.

Pezotettix discolor Scudder, S. H. 1897. Proc. U.S. Nation. Mus 20 (1124): 146.

Melanoplus discolor Hebard. 1917. Proc. Acad. Nat. Sci. Philad. 69: 268.

Melanoplus discolor Otte, D. 2012. Trans. Am. Ent. Soc. 138: 160.

Specimens examined.

Colorado, El Paso Co., 27 August 1938 (1♂) . Kansas, Glasscock Co., Garden City , 23 August 1913, F.W. Milliken (1♂) . Nebraska, Dawes Co, 1.7 mi SSE Whitney, off Hwy 20, 42.7001, -103.2496, 27 August 2022, M.L. Brust (4♂, 2♀) , Sioux Co., ca 2.0 mi SSE Whitney of HWY 20, 42.6667, -103.5152, 26 July 2022, M.L. Brust (2♂) . New Mexico, Curry Co., 1 September 1938 (1♂) . South Dakota, Fall River Co., 16.5 mi N of Ardmore, Indian Canyon Rd of Hwy 71, 43.2350, -103.61975, 8 August 2020, M.L. Brust (2♂) . Texas : Dallas Co., Dallas, C.V. Riley (1♀) . Ellis Co., 3 mi SW Cedar Hill , 32.5514, -96.9911, 24 July 2019, J.G. Hill, M.J. Thorn, B.S. Dunaway (1♀) . Hood Co., Cresson , 11 August 1955, Williams (1♂) . Lampasas Co., 15 mi W Lampasas , 31.0417, -98.4347, 21 July 2019, J.G. Hill, M.J. Thorn, B.S. Dunaway (1♀) . Shackelford Co., Albany , 20 August 1935, I.J. Cantrall (2♂) . Tarrant Co., 19 July 1927 (1♂, 1♀) .

Diagnosis.

Male cerci that are weakly falcate (Figs 2B , 5A, B ), and by the shape of the internal male genitalia which has simple and heavily sclerotized dorsal valves of the aedeagus that abruptly narrow into short filamentous tails distally (Fig. 5E ). The ventral valves are slightly shorter than the dorsal valves, are slightly arched posteriorly and have their distal ends bent medially (Fig. 5F ). Most similar to M. nelsoni , but M. discolor is easily separated from that species by having longer and more falcate male cerci, and much shorter filamentous tails on the dorsal valves (Fig. 5C-G ).

Measurements.

Male measurements. (mm): (n = 10) Body length 16.0-22.3 (mean = 18.8); pronotum length 3.7-5.0 (mean = 4.3); hind femur length 5.5-9.0 (mean = 7.0); cerci length 0.9-1.0 (mean = 1.0); basal width of cercus 0.5-0.8 (mean = 0.7); mid-cercal width 0.5-0.8 (mean = 0.7); cerci apex width 0.3-0.4 (mean = 0.3).

Female measurements. (mm): (n = 8) Body length 18.5-25.2 (mean = 21.3); pronotum length 4.3-6.3 (mean = 5.1); tegmen length 6.5-9.9 (mean = 8.0); hind femur length 10.5-15.8 (mean = 12.6) Dorsal ovipositor valve length 1.3-1.6 (mean = 1.5); ventral ovipositor valve length 1.0 (mean = 1.0).

Habitat.

Shortgrass or mixed grass prairie and Ashe juniper savannas (Fig. 15A ).

Distribution.

North Texas through the Great Plains to South Dakota west to New Mexico and Colorado (Fig. 14 ).

Etymology.

Discolor, Latin, of different colors or variegated.

Suggested common name.

Variegated pouncer.

Notes.

Specimens north of Texas tend to have a deeper red hind tibia (Fig. 15D, E ), This species has been observed eating Brickellia eupatorioides , false boneset ( Asteraceae ) (Fig. 15E ).

Figures

Figure 2. Lateral outlines of the male cerci of species in the Melanoplus discolor species group A M. nelsoni B M. discolor C M. corniculatus D M. Melanoplus walkeri E M. walkeri F M. susdentatus G M. kendalli H M. tonkawa I M. comanche.

Figure 3. Lateral views of the male aedeagus of species in the Melanoplus discolor group. DV: dorsal valve, S: sheath, VV: ventral valve. A M. nelsoni B M. discolor C M. corniculatus D M. comanche E M. kendalli F M. susdentatus G M. walkeri H M. tonkawa I M. balcones.

Figure 4. Dorsal views of the male aedeagus of species in the Melanoplus discolor group. DV: dorsal valve, S: sheath, VV: ventral valve. A M. nelsoni B M. discolor C M. corniculatus D M. comanche E M. kendalli F M. susdentatus G M. walkeri H. M. tonkawa I M. balcones.

Figure 5. Melanoplus discolor A dorsal view of male terminalia B lateral view of male terminalia C dorsal view of phallic complex D lateral view of phallic complex E dorsal view of aedeagus F lateral view of aedeagus G caudal view of the aedeagus H dorsal view of epiphallus I caudal view of epiphallus J habitus. Abbreviations: A: ancora, B: bridge, L: lophus, LP: lateral plate,

Figure 14. Distribution of species in the Melanoplus discolor group A broad view of the group, showing the wide distribution of M. discolor B distribution of Melanoplus discolor group species occurring in central Texas with the Balcones Escarpment indicated.

Figure 15. Habitat and live images of Melanoplus discolor A prairie remnant, Ellis County, Texas B male, Ellis County Texas C female, Ellis County Texas (Note: late afternoon sun altered the body coloration slightly) D male, Sioux Co., Nebraska E female eating false boneset, Sioux Co., Nebraska. E, D courtesy of Matthew Brust.