How do bee fly larvae develop in bee and wasp nests?

Bee flies (family Bombyliidae) are not themselves bees, but rather insects in the order Diptera that often mimic the appearance of bees.12

Regarding their development, the larvae of many bee fly species are parasitic on solitary bees. While specific details on how every species enters a nest can vary, these flies are known to target the nests of their hosts to complete their life cycle. Once the larvae hatch, they act as parasites, feeding on the host or the provisions intended for the host's offspring.1

It is important to clarify that bee flies are distinct from other insects that inhabit bee or wasp nests, such as the wax moth, which consumes beeswax, or cuckoo bees, which are parasitic relatives of non-parasitic bees that lay their eggs in the nests of other species. Unlike social insects that provide continuous care for their young, bee flies rely on these parasitic strategies to ensure the survival of their larvae.314