Hemigryllus Saussure, 1877

Cadena-Castañeda, Oscar J., 2025, Studies on Neotropical crickets: On the Hemigryllus Saussure, 1877 taxonomic placement (Orthoptera: Grylloidea), with comments on Gryllidae classification, including new species and records, Zootaxa 5661 (2), pp. 151-177 : 154-174

publication ID	https://doi.org/10.11646/zootaxa.5661.2.1
publication LSID	lsid:zoobank.org:pub:0A0D9440-1FEA-41A6-B214-32C4A2497A25
DOI	https://doi.org/10.5281/zenodo.16604446
persistent identifier	https://treatment.plazi.org/id/03E68792-FFAC-1B5D-B0FD-D36FFA6764DC
treatment provided by	Plazi
scientific name	Hemigryllus Saussure, 1877
status

Treatment

Hemigryllus Saussure, 1877 View in CoL

Redescription. In addition to the characters of the subfamily. Body moderately robust, surface with pilose texture. Coloration ochre with brown spots and stripes ( Figs. 1 View FIGURE 1 , 4 View FIGURE 4 , 5 View FIGURE 5 , 6 View FIGURE 6 , 9 View FIGURE 9 , 12 View FIGURE 12 ). Head slightly narrower than pronotum in dorsal view ( Figs. 2C View FIGURE 2 , 7C View FIGURE 7 , 10C View FIGURE 10 ), higher than wide in frontal view, vertex rounded ( Figs. 2A View FIGURE 2 , 7A View FIGURE 7 , 10A View FIGURE 10 ). Eyes ovoid, little protruding; ocelli ovoid ( Figs. 2A View FIGURE 2 , 7A View FIGURE 7 , 10A View FIGURE 10 ). Antennal sockets located little down at the middle level of the lateral margin of the eyes. Clypeus base rectangular and narrow, the posterior section narrower and longer; labrum ovoid ( Figs. 2A View FIGURE 2 , 7A View FIGURE 7 , 10 A View FIGURE 10 ). Maxillary palps mid-sized, first and second subequal in size and cylindrical; third as long as the first and second together; fourth slightly smaller than the third, last segment with apical oblique truncation ( Figs. 7B View FIGURE 7 , 10B View FIGURE 10 ). Mandibles symmetric and normally developed ( Figs. 2A View FIGURE 2 , 7A View FIGURE 7 , 10 A View FIGURE 10 ). Thorax. Pronotal disc wider than long, covered by few and short hairs; anterior margin concave, posterior margin broader than the anterior one, with the mid-section undulate ( Figs. 2C View FIGURE 2 , 7C View FIGURE 7 , 10C View FIGURE 10 ); lateral lobes square as wide as high, all margins almost straight ( Figs. 2B View FIGURE 2 , 7B View FIGURE 7 , 10B View FIGURE 10 ). Prosternum unarmed, triangular-shaped, with the posterior margin constricted; mesosternum quadrangular with posterior margin forming two rounded-angled lobes; metasternum almost as wide as mesosternum, slightly expanded and subcircular, posterior margin straight. Meso- and metanotum without glandular pits. Legs covered with abundant hairs, the dorsal and ventral margins of the fore and middle tibiae with bristles projecting from the hairs. Femora without spines; fore tibia short, with a tympanum ovoid and elongated, only on the inner side, apex with two inner ones, dorsal inner spur is the longest ( Figs. 2D View FIGURE 2 , 7D View FIGURE 7 , 10D View FIGURE 10 ); outer apex with one spur, shorter than the inner ones, the inner face of the spurs are excavated ( Figs. 2E View FIGURE 2 , 7E View FIGURE 7 , 10E View FIGURE 10 ). First and second tarsomeres of the first pair of legs covered by bristles, mainly on the ventral side ( Figs. 2E View FIGURE 2 , 7E View FIGURE 7 , 10E View FIGURE 10 ). Mid tibia with two apical sharp spurs similar in size on each side; first and second tarsomere covered by bristles, although less dense compared to the foreleg tarsi, last tarsomere of mid-leg unarmed and with a dorsal furrow. Hind tibia dorsally wide, with four long pubescent subapical spurs on each dorsal margin, and three apical spurs at the apex on both sides ( Figs. 2F View FIGURE 2 , 7F View FIGURE 7 , 10F View FIGURE 10 ); first tarsomere wide, with a dorsal furrow and spines along dorsal margins, and at apex armed with a spur on each side, the longest is the inner one ( Figs. 2G View FIGURE 2 , 7G View FIGURE 7 , 10G View FIGURE 10 ). Wings. Tegmina and hind wings developed; tegmina reaching apex of the abdomen or slightly exceeding it, subrectangular and with rounded posterior edge. Hind wings extending well beyond the abdomen. Tegmina with anal area well-developed, PCuP vein confluent into AA vein; AA and AP veins normally developed, rarely with an additional vein arising between AA and PCuP veins. Stridulatory vein (PCuA) straight. Harp crossed by three or four veins; mirror rather long, divided or not ( Figs. 2H View FIGURE 2 , 7H View FIGURE 7 , 10H View FIGURE 10 ). Apical area long, exceeding the mirror and chordal area length; the transverse veins connect with the longitudinal ones, forming cells, giving the appearance of a reticulated venation to the area. Lateral field with 9 to 14 veins ( Figs. 2H View FIGURE 2 , 7H View FIGURE 7 , 10H View FIGURE 10 ). Abdomen. Tergites without modification or specialization. Supra-anal plate subtriangular, with the posterior margin generally rounded; cerci covered with abundant long hairs; subgenital plate usually rectangular, longer than wide, with the posterior margin truncated or rounded. Male genitalia. Pseudepiphallus semi-tubular shape, surrounding and covering entirely or partially the pseudepiphallic parameres, tapering towards the apex and curving upward. Pseudepiphallic median lobe with a central incision in dorsal view, and the ventral margins generally undulated and setose. Pseudepiphallic paramere quadrangular at the base and usually with a thinner process that extends distally. Ectophallic fold moderately sclerotized, very small, and practically fused with ectophallic apodemes, not extending beyond the apex of the pseudepiphallic paramere. Ectophallic apodeme of medium size, projecting posteriorly. Rami in dorsal or ventral views, almost straight and separated at apex; in lateral view, ribbon-shaped and curving slightly upwards. Endophallic sclerite and endophallic cavity undeveloped ( Figs. 3 View FIGURE 3 , 8 View FIGURE 8 , 11 View FIGURE 11 ). Female. As the male in appearance and coloration ( Figs. 4A View FIGURE 4 , 5A View FIGURE 5 , 12A View FIGURE 12 ). Dorsal field of the tegmina with numerous transverse veins ( Figs. 4B View FIGURE 4 , 5B View FIGURE 5 , 10B View FIGURE 10 ). Supra-anal plate subtriangular, with the posterior margin usually rounded. Ovipositor of female notably reduced, covered mainly by the subgenital plate, or slightly protruding; valves reduced and spine-like, not close together as in other crickets, and not conspicuously diverging ( Figs. 4D, 4E View FIGURE 4 ). Subgenital plate rectangular, wider than long, posterior margin rounded or wavy ( Fig. 4C View FIGURE 4 ).

Type species. Hemigryllus kriechbaumeri Saussure, 1877 View in CoL stat. rev. by original monotypy.

Comments. This genus groups ten species, including the two new species described here. Its distribution is South American, with the greatest diversification in the Amazon ( Maps 1 View MAP 1 and 2 View MAP 2 ). A key for species identification is provided below, based on males, which excludes H. ortonii , which is only known from one female, as explained in this contribution.

Key to Hemigryllus species (adapted from Gorochov, 1996) based on males

1. Mirror of tegmina without dividing vein ( Figs. 2H View FIGURE 2 , 7H View FIGURE 7 ........................................................ 2 View FIGURE 2

Mirror of tegmina with a dividing vein ( Fig. 10H View FIGURE 10 )............................................................ 6

2. Tegmina with slightly curved chords................................................. H. kriechbaumeri View in CoL stat. rev.

Tegmina with strongly curved chords ( Figs. 2H View FIGURE 2 , 7H View FIGURE 7 ).......................................................... 3

3. Tegmina with rather short apical area and well-developed lanceolate cell ( Fig. 2H View FIGURE 2 ). Genitalia with short pseudepiphallus and comparatively large pseudepiphallic parameres ( Fig. 3 View FIGURE 3 )........................................................ 4 Tegmina with long apical area and reduced lanceolated cell ( Fig. 7H View FIGURE 7 ). Genitalia with rather long pseudepiphallus and variablesized pseudepiphallic parameres......................................................................... 5

4. Ventral margins of pseudepiphallus undulated and close together; inner surface of median lobe smooth; pseudepiphallic parameres with posterior process nearly straight and cylindrical....................................... H. woronovi Ventral margins of pseudepiphallus slightly undulated, almost straight, and separated ( Fig. 3A View FIGURE 3 ). Inner surface of median lobe covered with abundant hairs ( Figs. 3A, D View FIGURE 3 ); pseudepiphallic parameres with posterior process curving upwards and to outer margin ( Fig. 3C View FIGURE 3 )...................................................................... H. gorochovi sp. nov.

5. Ventral margins of pseudepiphallus nearly straight and moderately separated, exposing much of the pseudepiphallic parameres; median lobe in dorsal view with a deep incision running from the apex to near the basal margin; pseudepiphallic parameres short, posterior process conical and poorly elongated.................................................. H. sharovi

Ventral margins of pseudepiphallus wavy and close together, covering pseudepiphallic parameres ( Fig. 8A View FIGURE 8 ); median lobe in dorsal view with a short incision running only one-quarter of the length of the lobe ( Fig. 8B View FIGURE 8 ); pseudepiphallic parameres long ( Fig. 8C View FIGURE 8 ), posterior process cylindrical and prolonged ( Fig. 8D View FIGURE 8 ).................................. H. ankeri sp. nov.

6. Tegmina with small mirror, very long apical area, and reduced lateral cell. Genitalia with short basal part of pseudepiphallus; pseudepiphallic parameres with distinct proximal process and practically without distal process............... H. femineus

Tegmina with large mirror, shorter or medium-sized apical area, and only slightly reduced lanceolated cell. Genitalia with long or medium-sized basal parts of the pseudepiphallus; pseudepiphallic parameres with or without proximal and distal processes. ................................................................................................... 7

7. Tegmina with shorter apical area ( Fig. 10H View FIGURE 10 ). Median lobe of pseudepiphallus long ( Figs. 11A, B View FIGURE 11 ), and undulated in lateral view ( Fig. 11C View FIGURE 11 ); pseudepiphallic parameres almost without proximal process and with large distal process ( Fig. 11A View FIGURE 11 )...................................................................................................... H. columbi

Tegmina with medium-sized apical area. Median lobe of pseudepiphallus medium-sized, and progressively up-curved in lateral view; pseudepiphallic parameres with developed proximal and medium-sized distal processes......................... 8

8. Mirror divided into two unequal parts; the upper part larger than the lower. Pseudepiphallus almost rectangular, in dorsal view without divisions or depressions, in ventral view with wavy margins; pseudepiphallic parameres thin and with distal process cylindrical................................................................................ H. amazonicus

Mirror divided into two parts of similar size. Pseudepiphallus almost triangular, in dorsal view with a shallow depression encompassing much of the distal two-thirds; pseudepiphallic parameres conical and moderately widened, and with the distal process subtriangular........................................................................... H. vocatus

Placement of Hemigryllus View in CoL in Grylloidea

Since the original description of Hemigryllus , this genus was placed in the "Legion des Némobiites" ( Saussure, 1877), with the comment that it was an intermediate genus between Gryllus and Nemobius . Independently, another species had been previously described as Nemobius ortonii , placing it in the Gryllides group, although it was related to taxa of Nemobiinae ( Scudder, 1869). Scudder (1897) revised his initial posture on N. ortonii , considering it an aberrant and rather small form of Gryllus . However, he did not officially regroup it into any new or described genus.

In the early to mid-20th century, Hemigryllus remained classified under Nemobiinae by most authors ( Bruner, 1916; Hebard, 1928; 1931; Chopard, 1931; 1954), except for Rehn (1917), who grouped it under Gryllinae . Kirby (1906), in his catalog, divided Gryllinae into groups A, B, C, and D, which partially align with current families and subfamilies. Hemigryllus was included in Gryllinae A, which corresponded to taxa currently classified within Nemobiinae, such as Caconemobius Kirby , Paranemobius Saussure , and Nemobius Serville. Chopard (1967) , in his catalog, followed a line similar to Kirby, placing Hemigryllus in the tribe Nemobiini , which at that time was a tribe of Gryllinae .

Gorochov (1986a) established for the first time the subfamily Hemigryllinae as part of the family Eneopteridae , which functioned as a group that also included Eneopterinae , Phalangopsinae , and Landrevinae . The same author, in the same year, presented a phylogenetic hypothesis in which the group Eneopteridae is composed as follows: (( Hemigryllinae + Eneopterinae ) ( Phalangopsinae + Landrevinae )), differentiating from the cricket systematics at that time and ruling out the relationship of Hemigryllus with Nemobiinae ( Gorochov, 1986b).

Desutter (1987) proposed an uncertain position for Hemigryllus , although she suggested it might belong to Tafaliscinae . Otte (1994), without specific justification, established the tribe-level Hemigryllini within Nemobiinae, returning Hemigryllus to its traditional placement.On the other hand, Gorochov kept his position of granting subfamily status to Hemigryllinae , as evidenced in his comprehensive review of the ensiferan classification ( Gorochov, 1995). He provided phylogenetic proposals regarding Hemigryllinae , which presented the same resolution he had previously published ( Gorochov, 1986b). Subsequent publications by Gorochov (1996, 1997, 1999) followed this subfamily status, adding new species to Hemigryllus .

In the 21st century, no new species of Hemigryllus have been published. However, Chintauan-Marquier et a l. (2016), in the first comprehensive phylogeny of crickets with molecular evidence, included Hemigryllus in clade G, which corresponds to the family Gryllidae . An unknown species of Hemigryllus from French Guiana was grouped in a clade with Odontogryllini ( Landrevinae ) taxa, as if it were part of that tribe, with the following configuration: ( Brasilodontus riodocensis ( Odontogryllus setosus + Hemigryllus sp. )). This grouping is surprising since Odontogryllini does not cluster with other Landrevinae , suggesting that this subfamily is polyphyletic. Could the specimen identified as Hemigryllus in that study have been misidentified? Further molecular and morphological studies are needed to resolve this situation and better understand Hemigryllinae's and Landrevinae's phylogenetic placement.

Gorochov (2015) proposed a hypothesis on the evolution of the male copulatory apparatus or genitalia in crickets, presenting a phylogenetic framework with some adjustments to his previous contributions ( Gorochov, 1986b; 1995). Specifically, the clade containing Hemigryllinae remained similar, excluding Phalangopsinae in contrast to previous proposals: ( Landrevinae ( Eneopterinae + Hemigryllinae )), as the Eneopterinae subfamily group.

Desutter-Grandcolas et al. (2021) emphasized that the morphological characteristics of Hemigryllus clearly show that it does not belong to the Nemobiinae clade and that, according to the topology of Chintauan-Marquier et al. (2016), it is a Gryllidae s. str., although its position within the family is still uncertain.

With the historical account of the placement of Hemigryllus , it is evident that initially, it was included in Nemobiinae, and sporadically grouped in Gryllinae . Only with the contributions of Gorochov did this placement change, and this shift was reinforced by recent contributions from Chintauan-Marquier et al. (2016) and Desutter-Grandcolas et al. (2021), which ultimately ruled out its inclusion in Nemobiinae. In light of morphology, this paper proposes reestablishing the subfamily status for Hemigryllinae , given its unique morphology, as indicated in the subfamily and genus redescriptions provided here. Due to this unique morphology, its placement in traditional groups has not been satisfactory; on the contrary, it has proven controversial. However, treating it as a subfamily offers a clearer systematic framework and allows for efficient identification and differentiation of this taxon from other close relatives.

Regarding the classifications of Hemigryllus at different levels, generic, tribal, or subfamily, depending on the author, there is no consensus on recent proposals such as those by Gorochov (2015) and Chintauan-Marquier et al. (2016). Gorochov (2015) relates it to Eneopterinae and Landrevinae , as well as the Gryllinae subfamily group clade (( Gryllomiminae + Itarinae ) ( Gryllomorphinae + Gryllinae )); partially, both the Gryllinae and Eneopterinae subfamily groups correspond to the family Gryllidae , although Pentacentrinae is in the Podoscirtinae subfamily group, which currently corresponds to the family Oecanthidae (following the classification in the Orthoptera Species File by Cigliano et al., 2025). This contrasts with the proposal by Chintauan-Marquier et al. (2016), in which Pentacentrinae is part of Gryllidae , and Hemigryllus is in the Odontogryllini clade, not as a sister group to Eneopterinae .

Another phylogenetic proposal based on mitochondrial genomes, which unfortunately did not include Hemigryllus , was published by Yu et al. (2024). They optimized and reconstructed the patterns of the subapical spurs and dorsal spines of the hind tibia. Following the morphological approach and focusing on Gryllidae , Gryllinae is characterized by having only subapical spurs (except Sclerogryllini ), unlike Pentacentrinae , Landrevinae , and Itarinae (subapical spurs and dorsal spines exist in a non-alternating arrangement), and Eneopterinae (subapical spurs and dorsal spines exist in an alternating arrangement). Analyzing Hemigryllinae , its species only have subapical spurs, which morphologically would relate it to Gryllinae , differing from Gorochov's (2015) proposal of considering it a sister group to Eneopterinae , and also contrasting with Chintauan-Marquier et al. (2016), who place it within Landrevinae , Odontogryllini .

The characteristics of Hemigryllinae suggest maintaining its subfamily status, grouping it within Gryllidae based on molecular and morphological evidence. Unlike other Gryllidae groups found in the Americas, Hemigryllinae is the only subfamily with an exclusively South American distribution.