Oecanthus beameri, Collins & Lightfoot, 2022

Collins, Nancy & Lightfoot, David C., 2022, A new species of tree cricket (Orthoptera, Gryllidae, Oecanthinae) from Chihuahuan Desert gypsum dunes in the United States and a key to the nigricornis species group, Journal of Orthoptera Research 31 (2), pp. 181-189 : 181

publication ID	https://dx.doi.org/10.3897/jor.31.79036
publication LSID	lsid:zoobank.org:pub:A3AE807B-A4CE-48E9-94AA-DC30D4D113C8
persistent identifier	https://treatment.plazi.org/id/95CA19BE-72DB-41C7-915F-CE6AA5D5C9C1
taxon LSID	lsid:zoobank.org:act:95CA19BE-72DB-41C7-915F-CE6AA5D5C9C1
treatment provided by	Journal of Orthoptera Research by Pensoft
scientific name	Oecanthus beameri
status	sp. nov.

Treatment

Oecanthus beameri sp. nov.

Fig. 3A-F View Fig. 3 , 4A-D View Fig. 4 , 5A, C View Fig. 5 , 6A-F View Fig. 6

Diagnosis. -

The antennal markings of O. beameri sp. nov. can total two, three, or four, with the medial mark on the scape usually broken into two pieces ( Figs 3C View Fig. 3 , 4 View Fig. 4 ), while O. quadripunctatus has either two or four marks with the medial mark on the scape being a solid post, and O. celerinictus always has a solid medial mark on the scape and never lacks the upper outer mark on the scape and is never round. The two antennal marks on the pedicel of O. walkeri ( Collins and Symes 2012) touch, and those of O. argentinus touch or nearly touch, while the marks on O. beameri sp. nov. do not.

The male and female subgenital plates of O. beameri sp. nov. (female: wide shallow notch as in Fig. 5A View Fig. 5 ; male: rounded end as in Fig. 5C View Fig. 5 ) can be distinguished from O. quadripunctatus (female: deep narrow notch as in Fig. 5B View Fig. 5 ; male: tapered to a rounded tip as in Fig. 5D View Fig. 5 ). When next to each other, a male O. beameri sp. nov. has a lighter coloring and smaller proportion of tegmen width to abdomen width than a male O. quadripunctatus (Suppl. material 5). Oecanthus beameri sp. nov. lacks the dark black lines across the proximal portion of the hind tibiae that are very common on O. celerinictus , but faint lines can be present ( Fig. 3F View Fig. 3 ). The deep black setae on the hind femora of O. salvii ( Collins and Schneider 2020) are not present in O. beameri sp. nov. See below for more detailed diagnostic information.

Description. -

Face, pronotum, abdomen, and wings pale greenish-white ( Fig. 3A-D View Fig. 3 ), color number 97 ( Köhler 2012). Eye color pale green. Palpi pale whitish green. Tympanal membrane on fore tibiae whitish green. Tarsi, tibiae, and femora translucent pale mint green. Tibiae without black setae or lateral black lines. Cerci straight and translucent pale green. Scape and pedicel translucent whitish, and remainder of antennomeres translucent whitish. Ventral face of pedicel and scape each with black marks on pale whitish field ( Fig. 3C View Fig. 3 ). See examples of antennal marking variations in Fig. 4 View Fig. 4 .

Materials examined. -

Holotype: USA • ♂; New Mexico, Otero County, White Sands National Park ; 32.793055, -106.233611; 10 September 2021; D. Lightfoot leg.; on Poliomintha incana ; MSBA 74580 GoogleMaps . Paratypes: Same information as holotype: USA • 1♂; MSBA 74579 • 1♀ (dry pinned), 1♂ (in alcohol); MSBA • 1 ♂ (dry pinned); ANSDU • 1♂ (dry pinned); CAS • 1♂ (in alcohol); FSCA • 1♂ (in alcohol for DNA research); TAMU

Etymology. -

Specific epithet in recognition of Raymond Beamer who collected the specimens in 1932 that were discovered in the ANSDU collection in 2019. The common name, White Sands tree cricket, is for the location where this species was discovered with high potential for endemism.

Holotype measurements (mm). -

Body length 11.7; tegminal length 9.0, tegminal width 20.0; pronotal length 2.3, distal pronotal width 2.0; hind femur length 9.0; cercus length 2.8; stridulatory file length 2.3; stridulatory teeth number 48.

Male paratypes. -

(n=6) Body length (mm) 10.8-13.3; tegminal length 8.5-9.8; tegminal width 3.3-3.9; pronotal length 2.2-2.4; distal pronotal width 1.8-2.2; hind femur length 8.5-9.8; cerci length 2.7-3.1; stridulatory file length (n=5) 1.2-1.5. Right tegminal stridulatory teeth (as in Fig. 6A View Fig. 6 ) number (n=5) 45-49. Tegmina with veins as in Fig. 3A View Fig. 3 . Subgenital plate with a rounded end ( Fig. 5C View Fig. 5 ). Copulatory blades thin with a deep notch separating them fairly equal to the width of one blade ( Fig. 6B, C View Fig. 6 ), and a slight indentation at the medial side of the distal end of each blade (6D). The metanotal gland with a rounded triangular depression, bristles running horizontally across the upper edge of the cavity, and no posterior medial lobe ( Fig. 6E View Fig. 6 ). These key out and match the diagram in Walker and Gurney (1967) for a member of the Oecanthus nigricornis species group. As pointed out by Walker and Gurney (1967), species within a group are difficult to separate based on the metanotal gland.

Female paratype description. -

(n=1) Latticed vein pattern on translucent greenish-white wings. Abdomen pale white ( Fig. 3E View Fig. 3 ). Body length 11.5 mm; pronotal length 2.0, distal pronotal width 2.0; hind femur length 7.0; cerci 4.5; ovipositor length 3.5. The tip of the ovipositor flared ( Fig. 6F View Fig. 6 ) and extending just beyond the tips of the cerci. Distal end of subgenital plate with a wide, shallow notch ( Fig. 5A View Fig. 5 ). The only female collected ( Fig. 3E View Fig. 3 ) was missing the distal ends of the wings, thus dorsal photos not included.

Oviposition. -

The female mated while in captivity and oviposited approximately 24 times into stems of an undetermined species of sage in both nodal and internodal areas ( Fig. 7A, B View Fig. 7 ). Species in the varicornis and Oecanthus nigricornis groups of Oecanthus generally oviposit within the stem internodal areas, while species in the niveus group prefer to oviposit in the nodal areas ( Fulton 1915). Photographs of some Oecanthus nigricornis species group members’ oviposition marks can be viewed on the Orthoptera Species File website (Cigliano 2021), including O. quadripunctatus . It is unknown whether being in captivity affected the locations of oviposition by this O. beameri sp. nov. female.

Climate and habitat. -

On the day the tree crickets were collected, daytime temperatures reached 32-37°C, and cooled off to 26-31°C in the evening. Males were calling exclusively on hoary rosemary mint, P. incana , and were generally restricted to the tops of the gypsum dunes.