Eurhopalothrix oxente Celante and Celante, 2024

Celante, Gabriel Luiz, Barbosa Celante, Julia Mariah Galdino, de Sales Nunes, Vladimir & Jahyny, Benoit Jean Bernard, 2024, Eurhopalothrix oxente sp. nov. (Hymenoptera: Formicidae), a new riparian species of São Francisco River, northeastern Brazil, Revista Chilena de Entomología 50 (2), pp. 213-225 : 216-219

Eurhopalothrix oxente Celante and Celante , new species

( Fig. 1 )

http://zoobank.org/ urn:lsid:zoobank.org:act:FC2E821D-0351-49D9-92AD-1D912B5640BC

Type material. Holotype: Worker ; Brasil – PE, Petrolina, Serrote do Urubu, 19 – 20/12/2020, Lat. -9.368035, Long. -40.379047, LMSAAI61, LMS60AA, collector: G. L. Celante [MFCE014368]. Deposited at MFCE-LMS . Paratypes: seven workers collected in the same location as the holotype . Two specimens will be deposited at CPDC ( MFCE014367 , MFCE014369 ), two at DZUP ( MFCE014370 , MFCE014371 ), two at INPA ( MFCE014376 , MFCE014377 ), and one at MZSP ( MFCE014372 ). Furthermore , five specimens were kept in wet storage (ethyl alcohol), deposited at MFCE/LMS (MFCE014378, MFCE014379, MFCE014380, MFCE014381, and MFCE014382).

Diagnosis. Hairs squamate, uniform, obovate, and subappressed covering the dorsal surface of the body, scape, and legs; head wider than longer; mandibles triangular, with nine teeth of varied sizes, the fourth tooth notably longer than the others, and the proximal teeth curved towards the clypeus; clypeus with anterior margin relatively straight; eyes extremely reduced.

Definition. See Tab. 1. Data for the holotype are informed within brackets []; minimum and maximum measures for five paratypes (MFCE014367, MFCE014369, MFCE014370, MFCE014371, MFCE014372) and the holotype are informed within parentheses (). Measures: HL [0.49] (0.48 - 0.52). HW [0.55] (0.55 - 0.59). ML [0.14] (0.14 - 0.16). PW [0.39] (0.34 - 0.41). PmL [0.35] (0.32 - 0.39). SL [0.26] (0.24 - 0.27). SLL [0.08] (0.07 - 0.08). WL [0.61] (0.61 - 0.64). CI [112] (112 - 118). PI [110] (103 - 110). TL [2.23] (2.22 - 2.32).

Biology and distribution. The new species was found in a small fragment (70 m x 70 m) of riparian forest dominated by Inga vera Willd. subsp. affinis (DC.) T.D. Penn ( Fabales : Fabaceae : Mimosoideae). Relatively thick layers of litter accumulate below the canopy of these trees, with some points exceeding 30 cm in thickness ( Fig. 3 ). The specimens were collected in sifted litter and rotten wood samples from the forest floor. The riparian forest fragment is located on the left bank of the São Francisco River, in the Sub-middle São Francisco hydrographic region, northeastern Brazil, in the ‘Depressão Sertaneja Meridional’ ecoregion of the Caatinga Domain ( Velloso et al. 2002). The climate of the region is classified as hot semi-arid (‘BSh’ type in the Köppen climate classification), with a maximum temperature of 33 °C and a minimum of 20 °C; average compensated temperature between 24.8 °C and 28.1 °C; the highest rainfall rates are found in the months of January, February, and March; average annual rainfall between 354.0 mm and 559.2 mm during ‘usual years’, but with the possibility of ranging from 150 mm to above 800 mm ( Pimentel & Assis 2022); and average monthly evapotranspiration ranging from 172.83 mm (June) to 288.69 mm (October) ( Silva et al. 2015). Up until now, Eurhopalothrix oxente sp. nov. has not yet been found in collections carried out in the same municipality outside this riparian forest and in neighboring regions, on both sides of the river, in either shrub or arboreal Caatinga areas, and is only known in its type locality ( Fig. 4 ).

Etymology. The name is a reference to the interjection ‘oxente’, a typical expression of northeastern Brazil used to mean surprise or oddness.

Figures

Figure 1. Holotype of Eurhopalothrix oxente sp. nov. A. Lateral view. B. Dorsal view. C. Head in frontal view. Scale bar: A = 0.5 mm; B and C = 0.2 mm. / Figura 1. Holotipo de Eurhopalothrix oxente sp. nov. A. Vista lateral.B. Vista dorsal.C. Cabeza en vista frontal. Barra de escala:A = 0,5 mm; B y C = 0,2 mm.

Figure 3. Photo in the riparian forest where Eurhopalothrix oxente sp. nov. was collected, on the left bank of the São Francisco River in Petrolina, Pernambuco, Brazil. / Figura 3. Foto en el bosque ribereño donde Eurhopalothrix oxente sp. nov. fue recolectada, en la margen izquierda del rÍo São Francisco en Petrolina, Pernambuco, Brasil.

Figure 4. Map of part of South America with the distribution of Eurhopalothrix oxente sp. nov., and of some other specimens of the bruchi group (Caatinga limits modified from Lima 2021). / Figura 4. Mapa de parte de Sudamérica con la distribución de Eurhopalothrix oxente sp. nov., y de algunos otros especÍmenes del grupo bruchi (lÍmites de Caatinga de Lima 2021).