Renter: Existing cavities: Nests in hollow plant stems (e.g. Phragmites, Rubus).
Nesting material: Cell partitions and nest plug made of resin. (Benoist, 1929a; Ferton, 1894)
Cross & Notton (2017) report: "Nesting of H. rubicola has not been observed in Britain although the Dorset female was carrying pollen and so is assumed to have been nesting. Both Rubus spp., Phragmites australis, the stems of which are known to be used for nesting outside Britain, are abundant at Southern Park, Greenwich. In FranceH. rubicola has been reported nesting in Phragmites (‘roseaux’) and Rubus (‘ronce’), with the cells separated by plant resin or gum (Perez, 1890; Ferton, 1894; Benoist, 1929). More recently in the Czech Republic it has recently been reported by Bogusch, Astapenkova´ & Heneberg (2015) nesting in empty galls of Lipara spp. (Diptera, Chloropidae) on P. australis. In Portugal it nests in beetle burrows in wood with the nest closure being made of resin with small particles incorporated, probably sand, and some green particles, possibly leaf material or plant gum."