Melanoplus tonkawa, 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 tonkawa sp. nov.

Figs 2G , 3H , 4H , 13A-J , 14

Type material.

Holotype: 1♂, USA, TX, 1.5 mi NNW Ellinger, 29.8511, -96.7173, 14 July 2020, J.G. Hill; collected in post oak savanna. Deposited in the Mississippi Entomological Museum.

Paratypes: Texas: Fayette Co., 1.5 mi NNW Ellinger, 29.8511, -96.7173, 14 July 2020, J.G. Hill (2♂).

Diagnosis.

Male cerci broadly falcate (Figs 2G , 13A, B ), internal male genitalia with the aedeagal sheath that does not project to the distal edge dorsal valves. Dorsal valves are thin plates that are arched along the caudal margin and are produced laterally to the ventral valves, giving the aedeagus a narrow or thin appearance in caudal or dorsal views (Figs 3H , 4H ). The ventral valves are slightly shorter than the dorsal valves, are slightly arched posteriorly and have their distal ends bent medially (Fig. 13F ). Most similar to M. kendalli , M. balcones , and M. susdentatus . Melanoplus tonkawa is easily separated from M. kendalli by having an aedeagal sheath that does not reach the distal margin of the dorsal valves and the curved nature of the dorsal valves (Figs 7C-G , 13C-G ), from M. balcones by the shorter, rounded valves found in that species (Figs 9C-F , 13C-F ), and from M. susdentatus by the more rounded apices of the male cerci, less sclerotized and less broadly arching dorsal valves of the aedeagus (Figs 8C-G , 13C-G ).

Male measurements.

(mm): (n = 2) Body length 20-21 (mean = 20.5); pronotum length 4.2-4.5 (mean = 4.4); hind femur length 11.2-11.4 (mean = 11.3); cerci length 1.0-1.2 (mean = 1.0); basal width of cercus 0.6 (mean = 0.6); mid-cercal width 0.4 (mean = 0.4); cerci apex width 0.3 (mean = 0.3).

Habitat.

Post oak/live oak savanna.

Distribution.

In the vicinity of Fayette County Texas on the western edge of the North American Coastal Plain (Fig. 14 ).

Etymology.

Named in honor of the Tonkawa tribe of Native Americans who previously inhabited the area where this species occurs.

Suggested common name.

Tonkawa 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 7. Melanoplus kendalli 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 8. Melanoplus susdentatus 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 9. Melanoplus balcones 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 13. Melanoplus tonkawa 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.