Temnomastax beni Rehn & Rehn, 1942

Olivier, Renan S., Pujol-Luz, Cristiane V. A. & Graciolli, Gustavo, 2019, Review of Temnomastax Rehn & Rehn, 1942 (Orthoptera, Caelifera, Eumastacidae, Temnomastacinae), Zootaxa 4593 (1), pp. 1-78 : 29-32

publication ID


publication LSID


persistent identifier


treatment provided by


scientific name

Temnomastax beni Rehn & Rehn, 1942


Temnomastax beni Rehn & Rehn, 1942

http://lsid.speciesfile.org/urn:lsid: Orthoptera .speciesfile.org:TaxonName:39966

Figures 21 View FIGURE 21 and 22 View FIGURE 22

Temnomastax beni Rehn & Rehn 1942: 12 (identification key), 14 (original description), 16 ( Figures 1 View FIGURE 1 , 7 View FIGURE 7 , 12 View FIGURE 12 ); Descamps 1979: 144 (citation); Olivier 2014: 457 (citation), 458 (identification key), 460 ( Figure 5 View FIGURE 5 and citation), 2017: 235 (citation); Olivier & Aranda 2017: 7 (citation), 2018: 269 (citation).

Type locality. Bolivia, Rurrenabaque, Beni River , 14°30’S / 67°35’W, 227 m, XII.1921 (Mulford Biological Expedition; W.M. Mann.)— holotype ♂ and 1 paratype ♂ GoogleMaps .

Depository. Holotype: Smithsonian Institution’s Museum Support Center , Suitland, United States of America.

Etymology. Specific epithet refers to the Beni River in the Amazon basin, north of Bolivia, near the type locality ( Rehn & Rehn 1942).

Diagnosis. Medium (♂ = 19.7 mm). The only species of the Beni group, differs from the other Temnomastax species mainly by the absence of many characteristics, such as: distinct color on the 7 th and 8 th abdominal tergites of male, complete black ring on the distal region of metafemur, a dorsal spine on the outer margin of the 1 st metatarsomere. General color of body yellow-ocher. Macropterous. Male cerci tapered and slightly curved inward. Posterior margin of male subgenital plate with a large fistuliform process projected backward.

Redescription (based on photos). Male. Rurrenabaque, Beni, Bolivia, 21–22.XII.1921 (W.M. Mann & Mulford BioExpl. col.)\ TYPE Temnomastax beni Rehn & Rehn det. (printed/handwritten on red paper)\ U.S. N.M. Type 61104 (handwritten on red paper) [MSC]. Measurements (mm): bd 19.7, pt 2.60, tg 15.9, hf 13.3.— Head: Narrow in dorsal view ( Figure 21A View FIGURE 21 ). Fastigium very protruding in lateral view ( Figure 21B View FIGURE 21 ). Fastigium-occipital junction concave in lateral view ( Figures 21 View FIGURE 21 B—blue arrow). Dorsal margin of fastigium yellow laterally. Eyes moderately protruding in frontal view. Frons, clypeus and labrum yellow. Lateral regions of head with a yellow stripe between the posterior-ventral margin of eye and the occipital suture ( Figure 21B View FIGURE 21 ). Thorax: Pronotum: Slightly sellate with uniform curvature in lateral view ( Figure 21B View FIGURE 21 ). Pronotal disk brown and posterior margin rounded ( Figure 21A View FIGURE 21 ). Lateral lobes with a dorsal brown stripe and a ventral yellow stripe. Thoracic tergites ocher. Thoracic sternites yellow. Wings: Macropterous (tg/hf 1.195). Tegmina ellipsoidal; reaching the distal region of metafemora (> 6.0x the pronotum length); translucent with a light-brown color; apical region between Ma2 and Sc with wide and more rounded curvature than the region between Ma2 and Mp 2 in lateral view; C reaching about ⅓ proximal of tegmen length; Sc reaching the ¼ distal of tegmen; many oblique nervures present between C and Sc and between C and costal margin of tegmen; R reaching the apex, without ramifications; M bifurcated in Ma in the median region and in Mp1 and Mp2 a little beyond on, Ma bifurcated in Ma1 and Ma 2 in the ⅓ distal, all branches of M reaching the apex; an intercalary zigzag nervure present between Ma and Mp1; 1Cu reaching the median region, ⅓ distal curved and fused to 1A; 2Cu present, reaching the median region; 1A reaching the apex, yellowish; 2A present, rectilinear and well marked in the ½ proximal and sinuous and less evident in the ½ distal; 3A present ( Figures 21A, B View FIGURE 21 ). Membranous wings translucent. Legs: General color yellow-ocher. Black ring in the ⅓ distal of metafemora absent ( Figures 21A View FIGURE 21 , B—red arrows). A dorsal spine on the outer margin of the 1 st metatarsomeres absent. Abdomen: 8 th, 9 th, and 10 th abdominal tergites almost completely black, other tergites and abdominal sternites with darkened ocher. Epiproct trigonal elongated and with sharp apex. Cerci tapered, subcircular in transversal section, and with distal half slightly curved inward. Posterior margin of subgenital plate with a medial fistuliform process very projected backward ( Figures 21B View FIGURE 21 , C—green arrow). Phallic complex: Unknown.

Female. Unknown.

Sexual dimorphism. hf ♀ / hf ♂ (?).

Measurements. Holotype measurements presented herein were obtained from Rehn & Rehn (1942), as well as the following measurements (mm) of one more paratype male: bd 15.9, pr 2.44, tg 15.4, hf 13.0.

Intraspecific variation. According to Rehn & Rehn (1942), no variation was observed between the two specimens studied in the original description. The paratype has some distortions owing to the method of preservation, but the diagnostic characters do not differ from those observed in the holotype.

Material examined. Bolivia: Dep. Beni : Holotype ♂ (Photography)— TYPE Temnomastax beni Rehn & Rehn (printed/handwritten on red paper)\ Rurrenabaque , Beni , Bolivia, 21.Dec., W.M.Mann \ Mulford, BioExpl. , 1921- 22 \ U.S. N.M., Type, 61104 (handwritten on red paper) [ MSC]; Paratype ♂ (Photography)— Rurrenabaque , Beni , Bolivia, 21.Dec., W.M.Mann \ Mulford, BioExpl., 1921-22 \ Temnomastax beni Rehn & Rehn PARATYPE (printed/ handwritten on blue paper) [ ANSP] .

Distribution. Known only from the type locality ( Figure 22 View FIGURE 22 ).

Remarks. Taxonomy: Rehn & Rehn (1942) briefly discuss the morphological characteristics of this species in relation to those commonly observed in other Temnomastax species; however, they conclude that T. beni is a “typical” species of the genus. After this, Descamps (1979), when describing Eutemnomastax , briefly cites the diagnostic characters that differentiate Temnomastax from Eutemnomastax . Finally, this author emphasized that 1) the absence of a dorsal spine on the outer margin of the 1 st metatarsomere and 2) the macropterism of T. beni are characters incompatible with the genus Temnomastax , and pondered the possibility that this species could belong to a different genus. Recently, Olivier (2014) suggested that a more detailed study of the Temnomastacinae species be performed, especially of T. beni , which still lacks a description of the phallic complex, thus confounding a better grasp of its classification.

In the present work, however, T. beni is maintained in Temnomastax because it is impossible to study the phallic complex, a structure fundamental to understanding the relationships between genera and species (Descamps 1973a). However, in addition to those points presented by Descamps (1979), we now list some other features that are also incompatible with Temnomastax , or, at least, would represent very significant morphological variations compared to other species of this genus.

Temnomastax beni has a very protruding fastigium in lateral view; its tegmina and membranous wings have light brownish color, and they are translucent. The apex of tegmen is not perfectly rounded since the apical region of tegmen presents medial-anal margin less rounded than the medial-costal margin. In general, chromatic characters are incompatible, for example, the brown pronotal disk (apparent in pinned specimens), absence of a black ring on the ⅓ distal of metafemur, and 8 th, 9 th, and 10 th abdominal tergites predominantly black.

Chromatic characters: The holotype has a yellow stripe between the ventroposterior margin of eye and the occipital suture, as well as yellow ventral stripes on lateral lobes of pronotum, but this was likely caused by drying or method of preservation. In life, these two regions of the body are probably blue.


Michigan State University


Academy of Natural Sciences of Philadelphia














Temnomastax beni Rehn & Rehn, 1942

Olivier, Renan S., Pujol-Luz, Cristiane V. A. & Graciolli, Gustavo 2019

Temnomastax beni

Olivier, R. S. & Aranda, R. 2017: 7
Olivier, R. S. 2014: 457
Descamps, M. 1979: 144
Rehn, J. A. G. & Rehn, J. W. H. 1942: 12