Oecanthus pellucens (Scopoli, 1763)

Silva, Hugo Miguel, Avivar-Lozano, Laura, Gomes, Goncalo, Rhee, Howon, Dellinger, Thomas & Aguin-Pombo, Dora, 2024, New records of Oecanthus species (Orthoptera, Oecanthidae) in the Madeira archipelago, Journal of Orthoptera Research 33 (1), pp. 95-102 : 95

Oecanthus pellucens (Scopoli, 1763)

Fig. 2C, E, F, H

Gryllus pellucens Scopoli, 1763: page 139

Oecanthus pellucens : Uvarov 1937: 2 [ Rabaçal]; Chopard 1938: 221 [habitat]; Gardner 1960: 196 [Funchal, Santana]; Fernandes 1972: 307 [listed]; Lange 1990: 118 [Funchal, Câmara de Lobos] (records not confirmed).

Material examined. -

PORTUGAL • 1♂; Madeira Island, Câmara de Lobos, Boca da Corrida ; 32°42'40"N, 16°59'11"W; 1202 m a.s.l.; 25.XI.2020; G. Oliveria, T. Santos leg.; UMACI • 1♂; Madeira Island, Câmara de Lobos, Garachico ; 32°40'12"N, 16°59'19"W; 439 m a.s.l.; 28.X.2018; R. Marques leg.; on: Vitis vinifera ; UMACI • 2♂; Madeira Island, Calheta, Ponta do Pargo ; 32°48'49"N, 17°15'41"W; 317 m a.s.l.; 14.VI.2023; H. Silva, H. Rhee leg.; on: Hyparrhenia hirta E. Fourn; UMACI • 1 Nymph; Madeira Island, Funchal, Parque Ecologico do Funchal ; 32°42'25.0"N, 16°55'05.7"W; 1200 m a.s.l.; 01.VIII.2023; H. Silva, L. Soraya leg.; on: Rumex maderensis Lowe; UMACI .

Measurements. -

MADEIRA ISLAND - ♂: BL=12.98 ± 0.11 mm (n=2); EL=10.93 ± 0.37 mm (n=4); HW=1.23 ± 0.37 mm (n=4); FL=7.93 ± 0.57 mm (n=4).

Sounds. -

Regular gaps occur between each echeme in songs, which is also shown in Cordeo et al. (2009). The echeme repetition rate (the number of echeme per second) is approximately 1.0/s (Fig. 3D ), which resembles the 1.0-1.5/s between 20°C and 25°C reported by Ragge and Reynolds (1998).

Notes. -

The mean elytra length measurements of the males, averaging 10.93 ± 0.37 mm, align with the reported range of 9.00-11.00 mm provided by Braud et al. (2015). Additionally, the mean length of the protruding part of the inner wings, a key feature for distinguishing this species from O. dulcisonans , measured 1.23 ± 0.37 mm, surpassing the one millimeter reported by Reitmeier (2018) and Braud et al. (2015). Similarly, the mean length of the posterior femur, measuring 7.93 ± 0.57 mm, exceeded the values reported by Cordero et al. (2009). The specimens from Ponta do Pargo were discovered stridulating on a stem within a one-meter-high patch of Hyparrhenia hirta E. Fourn. near a lighthouse. We also captured a nymph amid the endemic Rumex maderensis Lowe, where some adults of the species were also heard. Previous records of O. pellucens report this species from five of the ten municipalities of Madeira Island: Ribeira Brava ( GBIF 2022), Funchal ( Chopard 1938, GBIF 2022), Porto Moniz ( GBIF 2022), Santana ( Chopard 1938), and Câmara de Lobos ( Lange 1990). These records are scattered across several institutions abroad, and most of them predate the description of O. dulcisonans in 1993. Others consist of online photographic records in which the main distinguishing character between the two species, the metasternal plate, is not visible. Since validating these records is challenging, the specimens documented in this paper represent the only valid first-hand data for this species on the Madeira archipelago. No specimens of O. pellucens were found on Porto Santo Island.

Figures

Fig. 2. Oecanthus dulcisonans (A, B, D, G) and Oecanthus pellucens (C, E, F, H) from Madeira archipelago. Metasternal plate (the dots represent parts of the structure that were not visible to draw) (A, D, E, F), body in dorsal view (B, C), and epiphallus in dorsal view (G, H). Photos: Thomas Dellinger. Scale bars: 1 mm (A, D, E, F); 10 mm (B, C); 0.5 mm (G, H).

Fig. 3. Photos of Oecanthus dulcisonans stridulating (A) and standing (B) on Hyparrhenia hirta E. Fourn at Ponta de Sao Lourenco, Machico, Madeira Island on June 17, 2023. Photos: Howon Rhee. Oscillograms of songs of O. dulcisonans recorded at 23 ° C in Porto Santo Island (C) and Oecanthus pellucens recorded at 22.5 ° C in a laboratory with an individual from Spain by Klaus-Gerhard Heller (D), from the Orthoptera Species Files Online (Cigliano et al. 2023).