Nesting biology of two species of oil-collecting bees of the genus Paratetrapedia s.l. (Apidae: Tapinotaspidini) in Argentina

Paratetrepedia is the richest genus in the tribe Tapinotaspidini and its species have a wide distribution in the Neotropical region; however, little is known about the nesting biology of its species. Here, we report information about two species: Paratetrapedia (Lophopedia) nigrispinis (Vachal) and P. (Paratetrapedia) leucostoma (Cockerell) in Argentina. Nests of both species were similar: brood cells were elongated ovals and were excavated in the wood, arranged in linear series of one to three. Brood cells were internally shiny (varnish-like), possibly due to the lining carried out by the females, and were partitioned with the sawdust obtained from the excavated cells. Our data suggest that both species showed a strong association with Malpighiaceae flowers (however, the number of brood cells analysed was very low [1 and 2 brood cells] and this fact suggests that the assumption of oligolecty can be speculative) and could have bivoltine life cycles with one rapid spring/early-summer generation, and a second generation in late-summer/autumn. These Paratetrapedia species shared common behavioural traits with other studied wood-nesting species of the genus, which we suggest calling them "carpenter oil-collecting bees".