I am looking for insight into transmission of parasites via botflies, specifically ectoparasitic Diptera.

I am studying a Dipteran fly whose larval stages are ectoparasites in birds’ nests, eating blood and tissue of nestling birds, while the adult flies are known so far to eat bird feces and fermenting fruits.

I am trying to find any information on previous literature, observations, and possibilities for ADULT flies (not the larval stage), like the species I study, to transmit blood parasites to birds. (other examples of this transmission to other animals would be welcome too).

Generally, it seems so far blood parasites need a biting vector to take a blood meal from the new host for transmission to new host. The mouthparts of my fly species of interest has a proboscis with lapping/sucking ability, but no evidence of teeth, so it does not seem suited for latching onto flesh or creating a wound. Despite this, we still have interest to ask for insights, advice on if blood feeding could be a possibility for this species/species with similar anatomy.

Any advice, thoughts, information is welcome. Thank you for your help!