First record of Cephalotes pusillus Latreille, 1802 (Hymenoptera: Formicidae) nesting in a Sceliphron sp. (Hymenoptera: Sphecidae) nest

Solitary wasp nests (Sphecidae) are often occupied by other arthropods when abandoned. However, occupation by ants such as Cephalotes Latreille, 1802 is still uncertain. Species of Cephalotes are arboreal and occupy pre-existing cavities, commonly tree hollows. In this respect, the objective of this study is to report the first record of the ant Cephalotes pusillus (Klug, 1824) (Hymenoptera: Formicidae) nesting in a Sphecidae nest in areas cultivated with coffee, Coffea arabica L. The nest was collected on july 5, 2024, in a coffee plantation area in the municipality of Inconfidentes, Minas Gerais, Brazil. This area is associated with a fragment of Atlantic Forest. In the nest of Sceliphron sp. (Hymenoptera: Sphecidae), 64 pupae, 94 adults and four queens of the ant were counted. The successful occupation by the ant may have occurred due to different factors, such as the size and resistance of the nest, the size of the entrance and the multiple cells that are formed inside the nest, which allowed the use of this nest as an incubation site for the ant's larvae. This is the first record of C. pusillus nesting in a Sphecidae nest, but this species is a generalist in terms of the cavities it uses, requiring further observations to confirm the frequency of this behavior.