RIDING ON ANTS: FIRST REPORT OF THE ASSOCIATION BETWEEN Attacobius nigripes (CORINNIDAE) AND THE LEAF-CUTTING ANTS Acromyrmex lobicornis (HYMENOPTERA, FORMICIDAE)

POMPOZZI, GABRIEL; FERNÁNDEZ CAMPÓN, FLORENCIA

Congreso; 22nd International of Arachnology; 2023

Attacobius spiders are known as myrmecophiles and association between these spiders withdifferent ant species were reported in Brazil. This genus, endemic to South America, belongsto the Corinnidae family and has 16 described species. Until now only three species are knownto be myrmecophiles, Attacobius attarun and A. luederwaldti were reported in close associationwith leaf-cutting ants of the genus Atta, and A. lavape with Solenopsis ants. However, theamazing riding behavior of these spiders on ants was only reported for A. attarun and A.luederwaldti. Spiders would live inside ant nests and are very hard to find, being difficult torecord their natural history. Attacobius nigripes (Mello-Leitao) was recorded in Chaco and Córdoba provinces in Argentina. It is the only species of the genus in this country and dataabout its natural history is unknown. In addition, males of this species remain undescribed.Here, we report for the first time the association between Attacobius nigripes and the leafcuttingants Acromyrmex lobicornis. We found spiders at night riding on worker ants in trailsand entrances of ant nests. These observations add a new myrmecophile species to the genusAttacobius and provide a new ant species to this kind of interactions. Moreover, this is the firstreport for the genus in Mendoza province, extending its current known distribution. The ridingbehavior on ants is reported for first time for Attacobius nigripes and the possiblemyrmecophile association between this spider species and the leaf-cutting ants Acromyrmexlobicornis is discussed.