A univoltine species; late May to mid or late August, rarely September (Else & Edwards, 2018; Amiet et al., 2004).
Parasites and predators: Stelis ornatula is a cleptoparasite in the nests of Hoplitis claviventris. Cocoons of the former possess a prominent apical nipple and a denser silken matrix (through which the contents of the cell cannot be seen), distinguishing them from those of its host. Stelis phaeoptera has also been cited as a cleptoparasite of H. claviventris (Tork in Blüthgen, 1919). Other inquilines are the cleptoparasitic sapygid wasp Sapyga quinquepunctata (Stöckhert, 1919), the chalcid parasitoid Eurytoma nodularis (Enslin, 1925), two ichneumonids in the genus Gambrus (Enslin, 1925)[as Kaltenbachia], and the ichneumonid Aritranis bellosa (Danks, 1971b)[as Hoplocryptus signatorius]. Danks reports that in stem-nests the ovipositor of the latter is thrust through both stem and cell wall, and the eggs laid on the young host larvae.