Melanoplus walkeri, Hill, 2023

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 walkeri sp. nov.

Figs 2E , 3G , 4G , 11A-J , 14 , 21

Type material.

Holotype: 1♂, USA, TX, Kendall Co., 7 mi NE Sisterdale, 30.0073, -98.5515, 22 July 2019, J. G. Hill, MJT, BSD; Collected on Ashe juniper hill; 281,486. Deposited in the Mississippi Entomological Museum.

Other specimens examined.

Texas: Kendall Co., 7 mi NE Sisterdale, 30.0073, -98.5515, 22 July 2019, J. G. Hill, M.J. Thorn, B.S. Dunaway (3♂, 3♀) .

Diagnosis.

Male cerci that are falcate with a very steeply curving ventral edge (Figs 2E , 11A, B ), internal male genitalia with the valves of the aedeagus projected dorsally with trifid, thinly sclerotized dorsal valves. (Figs 3G , 4G ). Most similar to M. corniculatus , but M. walkeri is easily separated from that species by having more steeply curving male cerci (Fig. 2D, E ), aedeagal valves that are produced dorsally instead of caudally (Figs 10C-F , 11C-F ), and the shape and level of sclerotization of the dorsal valves (Figs 10C-G , 11C-F ).

Measurements.

Male measurements. (mm): (n = 4) Body length 21.4-22.1 (mean = 21.7); pronotum length 4.2-5.0 (mean = 4.7); tegmen length 4.5-5.7 (mean = 5.1); hind femur length 11.2-11.9 (mean = 11.6); cerci length 0.9 (mean = 0.9); basal width of cercus 0.8-0.9 (mean = 0.9); mid-cercal width 0.5 (mean = 0.5); cerci apex width 0.3 (mean = 0.3).

Female measurements. (mm): (n = 3) Body length 22-24.2 (mean = 22.8); pronotum length 5.5-5.7 (mean = 5.6); tegmen length 6.0 (mean = 6.0); hind femur length 13.3-13.5 (mean = 13.4); Dorsal ovipositor valve length 1.4-1.6 (mean = 1.5); ventral ovipositor valve length 1.3-1.5 (mean = 1.4).

Habitat.

Ashe juniper/live oak savanna.

Distribution.

Found in the central eastern edge of the Edwards Plateau along the Balcones Escarpment (Fig. 14 ).

Etymology.

Named in honor of Jerry Jeff Walker an iconic Texas musician whose most influential album was recorded near the type locality of this species in the Luckenbach. Walker’s songs such as Hill Country Rain, Leavin’ Texas, and Sangria Wine brought me and my field team joy while traveling between field sites and added to the amazing ambiance of the Edwards Plateau.

Suggested common name.

Walker’s pouncer.

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 10. Melanoplus corniculatus sp. nov. 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.

Figure 11. Melanoplus walkeri sp. nov. 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.

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 21. Habitat and live images of Melanoplus walkeri sp. nov. A Ashe juniper savanna, Kendall Co., Texas B male, C male D female.