Typophyllum erosifolium Walker 1870
Creators: name: Braun, Holger
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Orthoptera
Phaneropteridae
Typophyllum
Typophyllum erosifolium

description: Typophyllum erosifolium Walker 1870
(Figs. 12, 13, 14, 15)
Typophyllum peruvianum Pictet 1888 syn. nov.
http://lsid.speciesfile.org/urn:lsid: Orthoptera.speciesfile.org:TaxonName:5481
T. erosifolium: Walker 1870: 464 (T. erosifolia), Kirby 1906: 350 (Mimetica erosifolia), Vignon 1925a: 275, Vignon 1931: 140, Beier 1960: 368, Braun 2002: 67, Braun 2008: 220; T. peruvianum: Pictet 1888: 29, and some other references; Typophyllum sp. 1: Braun 2002: 65 (“Pfeifendes Spaziergehblättlein“), Braun 2008: 220.
Examined specimens. Reserva Biológica San Francisco/Río San Francisco valley: male cbt001s01 (with sound recording), 1850 m, 30 September 1997; female cbt001s02, 1830 m, leg. H. Braun 14 July 1998; female cbt001s03, 2010 m, 26 July 1998; male cbt001s04 found riding on female cbt001s05, 1830 m, leg. F. Matt 12 August 1998; male cbt001s06 (sound recording) 1830 m, 4 June 1999; male cbt001s07 (sound recording), 1850 m, 8 June 1999; male cbt001s10, leg F. Matt 2002; Río Sabanilla valley 1640 m: male cbt001s08 (sound recording) and female cbt001s09, 5 September 1999; Bombuscaro 1200 m: female cbt007s01, captured as nymph and raised to adult, 8 January 2008; female cbt007s03; Alto Nangaritza, 1280 m, 8 April 2009; leg. H. Braun where no collector mentioned, all in collection of author.
Notes. T. erosifolium was described from a single female from the upper Amazon in northeastern Peru. The locality, Nauta (“Nanta” in original description, but corrected in Vignon’s and Beier’s revisions), is a small town in the Loreto Department with road and river access, at about 100 m, and might not be the actual collection site. No further records seem to be published. The type specimen’s tegmina tips are damaged (photos in OSF), but it is visible that the distal anal margin is undulated or “deeply notched” (Walker 1870), from which the species name is derived. T. peruvianum was also described from a unique female from Peru, without further locality specifics. This specimen (photos in OSF) shows the same tegmen shape as T. erosifolium, only without emarginations, and also the venation is very similar. There is a female specimen from Yarinacocha in the UMMZ collection (photos in OSF). This locality is in eastern Peru in the Ucayali Department at about 150 m. Apparently there are also records from Ecuador (Beier 1960). Since the development of the anal margin is intraspecifically variable in females (found in this species, T. egregium and T. morrisi sp. nov.), T. erosifolium and T. peruvianum are considered to represent the same species.
Description. The internal tympanal chamber walls are expanded, extending well beyond the dorsal surface of the fore tibia, placing this species in the third group according to Vignon (1925a). Apart from the general shape of the sexually dimorphic tegmina (Fig. 13) there are no really disctinctive characters. Of the six females found in the area, five have tegmina with uniform anal margin, whereas in one the distal portion is undulated. In males the anal margin is undulated to varying degrees, and there is a deep distal emargination of the costal margin which almost reaches the radial vein. In the male holotypes of T. curtum and T. mutilatum, the only remaining species in the third group, this emargination is fairly far separated from the radial vein (photos in OSF). In females the pronotum has two elongated tubercles at the anterior margin, each located about one forth of pronotum diameter from the lateral edge, and in the middle of the posterior margin there is sometimes a small, basally fused two-tipped process. The speculum of the right tegmen in males is fairly stiff, whitish, and barely translucent. The prosternum has no spines, the lateral tips of the mesosternm are developed as delicate spines (almost twice as long as distal width of maxillary palp), and the metasternum has more robust spines of about the same length.
Coloration. Variable, light of dark brown, sometimes greenish or almost completely green (Fig. 15). The dorsal surface of the middle tibiae can be white in the lower half. One female had small white tubercles on the tegmina (Fig. 15 C), which became dark after death. Another female had extensive whitish spots (Fig. 14). Especially the tegmina are distinguished by numerous tiny accessories that perfect the resemblance to a real decaying leaf, like transparent parts imitating holes, microscopic dark and whitish tubercles resembling small fungi, bright lichenous marks, or greenish parts as if there grew moss.
Measurements. Tegmen length in males 15–19 mm and in females 28–36 mm, hind femora in males 12–13 mm and in females 15–17 mm (in T. peruvianum 21 mm according to the description and missing in the holotype, tegmina 32 mm).
Acoustic behaviour. This species calls unwearily, sometimes many minutes without interruption. The pulse length usually is about 55 ms (ranging from 50 to 70 ms depending on the individual) and the intervals between the pulses last alternately 160 and 400 ms at 19°C, or 230 and 670 ms at 16°C in the natural habitat. The frequency spectrogram shows a very narrow peak at 18–19 kHz and very small peaks of the harmonics at 37 kHz and 55–56 kHz (Fig. 19 D). While individuals can be heard over fairly long distances using a bat detector, with the unaided human ear the song is perceivable over only 1–2 m in the forest to a few meters in a quiet room, reminding of some very tiny machine in need of lubrication. Calling begins with the short equatorial dusk and the males mostly sit rather low in the vegetation, apparently up to 3– 4 m. Within the range of this species in the well-investigated Reserva Biológica San Francisco, listening at night with a bat detector, very rarely more than one calling male was heard from a particular spot, and mostly none. This indicates a very low population density. At the sites Bombuscaro and Alto Nangaritza this species was never heard, despite extensive listening.
Mating behaviour. One male (cbt001s05) was found at night riding laterally on the wings of a female (cbt001s04), the whole ensemble sitting on the flower of a species of Solanaceae. This indicates that this little walking leaf shares the curious piggyback-behaviour typical of the genus Typophyllum, described above for T. egregium.
Distribution. Eastern slope and foothills of Andes in southern Ecuador and Amazon region of northern Peru. The conspicuous calling song of this little walking leaf allowed an assessment of its altitudinal distribution range in the San Francisco and Sabanilla river valleys (Fig. 20 B). There it occurs up to 2100 m inside the forest, especially in vales and ravines, although never close to flowing water that would drown its song in broad-band ultrasound noise.
description: Published as part of Braun, Holger, 2015, Little walking leaves from southeast Ecuador: biology and taxonomy of Typophyllum species (Orthoptera, Tettigoniidae, Pterochrozinae), pp. 1-32 in Zootaxa 4012 (1) on pages 15-19, DOI: 10.11646/zootaxa.4012.1.1, http://zenodo.org/record/289354