Research Article |
Corresponding author: Oscar J. Cadena-Castañeda ( ojccorthoptera@gmail.com ) Academic editor: Corinna S. Bazelet
© 2020 Oscar J. Cadena-Castañeda, Daniela Santos Martins Silva, Diego Matheus De Mello Mendes, Marcelo Ribeiro Pereira, Fernando Campos De Domenico, Carlos Frankl Sperber.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Cadena-Castañeda OJ, Silva DSM, Mendes DMM, Pereira MR, Domenico FC, Sperber CF (2020) Review of the tribe Amorphopini (Orthoptera: Tetrigidae: Metrodorinae): Pygmy moss-lichen tetrigids from the Amazon rainforest. Journal of Orthoptera Research 29(1): 45-62. https://doi.org/10.3897/jor.29.33717
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The tribe Amorphopini Günther, 1939 is reviewed. It consists of two genera: Amorphopus Seville, 1838 and Eomorphopus Hankock, 1907 with three Neotropical species: Amorphopus notabilis Serville, 1838, Eomorphopus antennatus (Bolívar, 1887), and Eomorphopus granulatus Hancock, 1907. Two species are transferred from Amorphopus to the genera Metrodora Bolívar, 1887 and Crimisus Bolívar, 1887, and two new combinations are proposed: Metrodora gibbosula (Walker, 1871), comb. nov. and Crimisus humeralis (Walker, 1871), comb. nov. New synonyms are proposed: Amorphopus notabilis Serville, 1838 = Amorphopus griseus Bolívar, 1887, syn. nov.; Metrodora gibbosula (Walker, 1871) = Platytettix reticulatus Hancock, 1906, syn. nov.; and Crimisus humeralis (Walker, 1871) = Allotettix bolivianus Brunner, 1913, syn. nov. Neotypes of Amorphopus notabilis and Eomorphopus antennatus as well as the lectotype of E. granulatus are designated. The description of Amorphopus testudo Saussure, 1861 is based on an immature specimen and we considered it as nomen dubius and the type depository of Eomorphopus purpurascens is unknown so we considered it, too, as nomen dubius. The tribe Amorphopini and all included taxa were redescribed and illustrated. A key to the genera and species is provided. Data on distribution, behavior, camouflage with lichens, polychromy, as well as ecological aspects of the species are reported.
behavior, camouflage, chromatic variation, lectotype, neotype, redescription
Metrodorinae is a cosmopolitan subfamily currently composed of five tribes (Cleostratini Bolívar, 1887; Amorphopini Günther, 1939; Clinophaestini Storozhenko, 2013; Miriatrini Cadena-Castañeda & Cardona-Granda, 2015; and Ophiotettigini Tumbrinck & Skejo, 2017) and about 70 genera of uncertain placement (
Amorphopus was described by
Eomorphopus was defined by
In the present study, we review the tribe Amorphopini and its species, study the status of the genera and species and their ecological associations and behaviors, and provide an updated identification key. Additionally, we also present updated distribution maps for all known Amorphopini species. This paper is part of the cooperative study of Neotropical Tetrigidae led by Daniela Santos Martins Silva and Oscar J. Cadena-Castañeda.
Specimen preparation.—The studied specimens were deposited in the following institutions: Colección de Artrópodos y otros Invertebrados de la Universidad Distrital Francisco José de Caldas, Bogotá, Colombia (CAUD), Academy of Natural Sciences, Philadelphia, Pennsylvania, USA (ANSP), Naturhistoriska Riksmuseet, Sweden, Stockholm (NHRS), The Natural History Museum [formerly British Museum (Natural History)], London, England (BMNH), Naturhistorisches Museum Wien, Vienna, Austria (NMW), Museo Natural de Ciencias Naturales, Madrid, Spain (MNCN), and Coleção de Invertebrados do Instituto Nacional de Pesquisas da Amazônia, Manaus, Brazil (INPA).
Specimen photos were taken with a Leica DFC295 attached to a stereomicroscope M205. The photographs of ANSP types were taken in a photo lightbox with a Canon EOS T3i digital camera equipped with a EF 100mm f/2.8 L macro lens. Photographs of living specimens were taken using a Nikon D7100 digital camera, with a 60 mm 2: 8 lens. The illustrations were made using Adobe Illustrator CS6 and Adobe Photoshop CS6.
Terminology and measurements follow
Maps and distribution data.—Maps were drawn with Simplemappr (
The type genus Amorphopus Serville, 1838 and Eomorphopus Hancock, 1907.
Small to medium size, robust insects with the body depressed dorso-ventrally (Figs
Amorphopini was erected as a tribe by
Platythorus is monotypic with only one female type, Platythorus camurus Morse, 1900, and occurs in Nicaragua and Costa Rica (
The Amorphopini species, as well as other species in South America, exhibit a very peculiar geographical distribution (see
1 | Body moderately depressed (Figs |
2 |
– | Body strongly depressed (Figs |
Amorphopus notabilis Serville, 1838 |
2 | Mid-sized (♀ 19–19.5 mm, ♂ 18 mm). Apex of the lateral lobe of the pronotum (sideway projection) triangular shaped and moderately sharp (Figs |
Eomorphopus antennatus (Bolívar, 1887) |
– | Small sized (♀ 16.5–17.5 mm, ♂ 15–16 mm). Apex of the lateral lobe of the pronotum (sideway projection) rounded (Figs |
Eomorphopus granulatus Hancock, 1907 |
Amorphopus notabilis Serville, 1838.
Body strongly depressed dorsoventrally and minutely granulate (Figs
COLOMBIA • ♀; Amazonas, PNN Amacayacu; 03°44'19"S, 70°13'7"W; C. Rodríguez leg (CAUD).
Head. Not protruding from the body; face very distinctly oblique (Fig.
Male. Similar to the female, except for the post-abdomen characters (Fig.
Coloration. Predominantly white with scattered gray spots. Face and ventral surface of the body black with scattered whitish bands; pronotal disc from the level of the third pair of coxae with gray stripes, which extend and alternate towards the posterior area of the pronotum; fore femur white, fore tibia black with a white ring in the mesal region; femur and mid tibia, as well as the basal half of the hind femur, light pink, distal half of the hind femur white with gray stripes in similar appearance to the pronotal disc (Fig.
The margin undulations of the fore and mid femora may be more conspicuous in some specimens and the lateral lobes with the posterior angles may have sinuato-dentate or serrato-crenate margins.
Female. CFP: 14.0–15.5; PL: 13.6–14.2; PLB: 5.5–5.9; FF: 2.6–2.8; FL:2.1- 2.3; MFL: 2.7–3.0; MTL: 2.6–2.9; HL: 6.0–6.2; HW: 1.7–1.9; HL: 4.3–4.6. Male. CFP: 11.5–12.2; PL: 11.2–11.5; PLB: 4.8–5.1; FF: 2.3–2.5; FL: 2.0–2.1; MFL: 2.9–3.1; MTL: 2.0–2.2; HL: 5.1–5.5; HW: 1.8–2.0; HL: 3.9–4.1.
Museum specimens. BRAZIL • 1♀. Amazonas, Manaus, Reserva Adolpho Ducke; 02°55'49"S, 59°58'31"W; 14–18 Apr. 2010, Rede entomológica, V. Linard leg.; AM-010, km 26 • 2♀♀; same collection data as for preceding; Coleta manual, D.M.M. Mendes leg. • 1♂. Amazonas, Manaus. ZF2, km 14; 02°35'21"S, 60°04'55"W; 1–15 Apr. 2016, Malaise grande no chão, J.A. Rafael and F.F. Xavier F leg. • 1♀. Amazonas, Tefé, Terra Firme; 03°25'19"S, 64°37'05"W; 10–26 Jun. 2016, malaise, J.A. Oliveira, D.M.M. Mendes and J.A. Rafael leg. (INPA). Photographic records. ECUADOR • Sumaco NP, Bigal River Forest Reserve (Arthur Anker). PERU • Huánuco, Tingo María (Huamán Cuespán et al. 2014).
Currently A. notabilis has two synonyms: Tetrix cnemidotus Burmeister, 1838 and Amorphopus caiman Saussure, 1861, both synonymized by
To the two remaining species of the genus, the following nomenclatural acts are proposed: 1. A. gibbosulus Walker, 1871 is transferred to Metrodora Bolívar, 1887, and it is synonymized with Metrodora reticulata (Hancock, 1906) syn. nov. (originally described as Platytettix reticulatus Hancock, 1906) under Metrodora gibbosulus (Walker, 1871) comb. nov. This synonym is proposed by comparison of the type specimens of both species. It is observed that there is no variation in the shape of the fastigium of the vertex, since both species have a broad frontal costa, similar to the species of the subfamily Cladonotinae. The pronotum has a curvature in the prozone that rises significantly; the apex of the pronotum is curved slightly upwards and the lateral lobes of the pronotum project towards the sides, with the inferior margin triangular in shape. Since these diagnostic characters are present in specimens of both species, they cannot be maintained as separate specific entities, much less belonging to different genera.
2. Similarly, A. humeralis (Walker, 1871) (=Tettix humeralis) is transferred to Crimisus Bolívar, 1887, and it is synonymized with Crimisus bolivianus (Bruner, 1913), syn. nov. (originally described as Allotettix bolivianus Bruner, 1913) under Crimisus humeralis (Walker, 1871), comb. nov. The type specimens of both species are females, but, unfortunately, the legs in the holotype of A. humeralis are missing, so the legs were not compared. Nevertheless, both species share the same characteristics: narrow frontal costa, lower margins of the pronotal lobes rounded, without projecting to the sides as in the previous case, subgenital plate triangular, with a small prolongation at the apex. The aforementioned characters are observed in the type specimens of both species, indicating that they belong to a single species. Since they do not have expanded anterior and middle femora, it is ruled out that they belong to the Amorphopini tribe, fitting better in the genus Crimisus.
The two species described by
Finally, the genus Amorphopus is kept monotypic and its known distribution is extended through the Amazonian slope, similarly to Pterochroza ocellata (Linnaeus, 1758), a species that was once considered several different species, but is now known to be a single, very variable species (
A neotype specimen is designated as the carrier-name of the species and is supported by the following reasons (
The Brazilian specimens were collected only in non-flooded ombrophilous forests (Terra Firme). In this environment they are usually found on the trunk and branches of fallen trees, where, due to their coloration and flattened body, they are easily confused with the tree’s bark. Once physically stimulated, the specimens exhibited thanatosis behavior, where the individual remained immobile, leaving its femurs parallel to the body, with the lobes of the femora that mimic foliage lying alongside the body and the tibia folded against the femora. Thus, the body of the insect is very similar to a small fragment of bark, and it remains in this position for several minutes even on physical stimulation. Only after several minutes did the observed specimens leave the thanatosis behavior and move (D. Mello Mendes pers. obs.).
Eomorphopus antennatus (Bolívar, 1887).
Body moderately depressed dorsoventrally (Figs
For a long time, Eomorphopus species were described as Amorphopus, except for E. purpurascens, which was originally described as Acrydium purpurascens by
The Brazilian specimens were collected in lowland floodplains in areas of the Solimões River and non-flooding ombrophilous forests (Terra Firme). They are commonly found in litter on the ground and occasionally on trunks of fallen trees. They are usually found in the same environment with other pygmy grasshoppers, such as Scaria (
Eomorphopus granulatus
Lectotype female, by present designation, deposited at ANSP and labeled as follows: “Eomorphopus granulatus Hancock H573 [handwritten] TYPE [printed, red label]/Hancock’s [printed] Type Eomorphopus granulatus [handwritten, white label]/Dutch Guiana [handwritten, white label]”. Conservation status. Bad condition, both antennae missing; specimen glued on card and remnants of fungi on body. Paralectotype male, by present designation, deposited at ANSP and labeled as follows: “Eomorphopus granulatus Allotype Hancock ♂ [handwritten] PARATYPE HEBARD CLN [printed, yellow label]/Dutch Guiana [handwritten, white label]”. Conservation status. Bad condition, both antennae missing; right fore and middle tarsi missing; specimen glued on card and remnants of fungi on body.
(Female lectotype, Fig.
Male (paralectotype, Fig.
Similar to female, except: Head. Frontal view (Fig.
Measurements (from additional specimens studied; in mm).
Female. CFP: 18; PL: 15.2; PLB: 5.8; FF: 3; FL: 3.2; MFL: 3.5; MTL: 3.7; HL: 8; HW: 2.4; HL: 7.2. Male. CFP: 16.5–17.4; PL: 15.0–16.0; PLB: 5.0–5.2; FF: 2.2–2.5; FL: 2.8–3.0; MFL: 3.0–3.1; MTL: 3.1–3.2; HL: 7.0–7.5; HW: 2.0–2.2; HL: 6.4–6.6.
COLOMBIA • 1♀; Putumayo, Puerto Asis, Vda. Nariño, Nariño; 0°29'20.9"N, 76°24'23.6"W; 273 m; 25 Mar. 2015; N. Jimenez leg. • 1♂; Caquetá, Florencia, Corregimiento Venecia, Vereda Balcanes, Granja Agroecológica Balcanes de la Universidad de la Amazonia; 01°25'34.7"N, 75°30'58,6"W; 266 m; 21 Sep. 2017; D. Cabra leg. (CAUD). BRAZIL • 1♂; Amazonas, Uarini, Boca do Mamirauá; 03°07'29.4"S, 64°47'32.1"W; 5 Sep. 2018; D.M.M. Mendes, J.C. Oliveira and J. Oliveira leg (INPA).
Eomorphopus granulatus
COLOMBIA • ♀; Amazonas, San Juan de Loreto Yacu; 03°37'0"S; 70°33'59.3"W; 180 m; N. Ruiz leg. (CAUD).
Female. This species is very similar to E. granulatus, but E. antennatus is larger. Furthermore, it is differentiated by the following characters: Body surface more granulated than E. granulatus (Fig.
Male. Similar to the female, distinguished by the ambisexual characters (Fig.
Variations
Measurements (in mm)
The main variations observed in this species are related to the coloration, that will be detailed later. Morphologically, the undulations of the middle and anterior femur may be more conspicuous in some individuals than others, although it was observed that they are more conspicuous in males than in females. Moreover, the undulations of the dorsal margin of the anterior femur can vary from two, three, or four, distorting the use of this character to separate the two species of Eomorphopus. (
Measurements (in mm)
Female. CFP: 19.4–19.5; PL: 17.4–17.9; PLB: 5.5–5.9; FF: 3.4–3.6; FL: 2.7–3; MFL: 3.3–3.4; MTL: 3–3.3; HL: 7.1–7.3; HW: 1.9–2.2; HL: 6.7–6.8. Male. CFP: 18.3; PL: 16.4; PLB: 5.5; FF: 2.8; FL: 2.7; MFL: 3.6; MTL: 2.8; HL: 7.4; HW: 2.3; HL: 6.1.
Museum specimens. COLOMBIA • 1♀; same data as neotype • 1♀; Amazonas, Leticia; 27 Oct. 1996. • 1♀; La Pedrera; 100 m; 18 May. 2011; C. Linares. • 1♂; Caquetá, Florencia, Vda. La Victoriosa, Centro de Investigaciones Amazónicas CIMAZ, Macagual. 01°30'37"N, 75°40'29"W; 233 m.; 20 Sep. 2017; A. Quiroga leg. • 1♂; Meta, San Juan de Arama, Bosque de Galeria, Caño Curia; 24 Sep. 1987. (CAUD). BRAZIL, • 1♀1♂; Amazonas, Manaus, Bosque da Ciência, INPA; 1–20 May. 2010; J.T. Câmara leg. • 1♀; same data collection data as for preceding; 22 May. 2009; coleta manual, T. Mahlmann leg. • 1♀; Amazonas, Rio Abacaxis; 05°15'09"S, 58°41'52"W; 35m; 27–29 May. 2008; Armadilha luz sobre o barco, J.A. Rafael e equipe leg. • 1♂; Amazonas, Manaus, Reserva Adolpho Ducke, km 26; 02°55'49"S, 59°58'31"W; 30 Apr. – 4 May. 2014; Coleta manual, K.F.S. Cezar leg. • 2♀; Amazonas, Tefé, Lago Tefé, Ilha em frente de Tefé; 03°19'55"S, 64°41'11.9"W; 1 Sep. 2018; Coleta em floresta de várzea, D.M.M. Mendes, J.C. Oliveira and J. Oliveira leg. • 1♂; Amazonas, Uarini, Boca do Mamirauá; 03°07'29.4"S, 64°47'32.1"W; 5 Sep. 2018; Coleta em floresta de várzea, D.M.M. Mendes, J.C. Oliveira and J. Oliveira leg. • 1♀; Amazonas, Careiro Castanho, BR-319, km 181, Sítio São Paulo; 04°12'48"S, 60°49'04"W; 24 Mar. 2017; J.A. Rafael and F.F. Xavier F. leg. Photographic records. PERU, • 1♀; Loreto Tamshiyacu-Tahuayo Reserve.
Eomorphopus antennatus was described by
A neotype specimen is designated as the carrier-name of the species and is supported by the following reasons (
The species of this tribe have the peculiarity of camouflaging themselves among lichens and bryophytes in humid environments of the Amazon (
The most striking case is of A. notabilis. The individuals of this species exhibit a peculiar design that simulates the surface of trees or rocks covered by diverse lichen and bryophyte communities (Fig.
Color variation is more conspicuous in Eomorphopus species. The individuals of this genus are bluish black, yellowish with brown spots of different shades, light or dark brown (Fig.
The study has benefited with grants and facilities from CNPq/Programa SISBIOTA Brasil (Edital MCT/CNPq/MMA/MEC/CAPES/FNDCT e FAPEMIG–Ação Transversal/FAPs 166 n° 47/2010, Proc. n° 563360/2010–0), PROTAX/CNPq/FAPEMIG (Proc. n° 440664/2015–2 and APQ – 04154-15), and FAPEMIG APQ–04154–15. We especially thank Jason Weintraub and Daniel Otte for allowing access to type material of Orthoptera deposited at the Academy of Natural Sciences of Drexel University (ANSP). Fundação de Amparo à Pesquisa do Estado do Amazonas – FAPEAM provided a grant for master studies to DMMM (Edital 016/2006, Proc. 1437/2007). Jonas Alves de Oliveira and Jomara Cavalcante Oliveira provided support during field work and João Rafael Alves-Oliveira helped in revising the manuscript. Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), provided funding and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) provided a research grant (Process: 300019/2017-3). The photographs of types were taken during the execution of the projects: “The Neotropical Tetrigidae (Caelifera: Tetrigoidea) deposited in the Academy of Natural Sciences of Drexel University, Philadelphia, USA” and “Photographic, sound and distributional data to some Neotropical Orthoptera Groups and Colombian Phasmatodea” financed by The Orthopterists’ Society. Finally, we thank Dr. Josef Tumbrinck for his important comments on the manuscript.