Red bugs (
Tegastes acroporanus) wouldn't accept monti as a host. Eric Bornemon has demonstrated that without a proper
Acropora host, they would rather die (roughly 5 days) instead parasitizing
Montipora. However, another commonly seen "black bugs" (sometimes incorrectly reported as red bugs) would infest
Montipora and
Montipora only.
Here is a very comprehensive list of commonly seen parasites, their hosts and treatment:
Aquarium Corals: Stony Coral Parasites: Red and Black Bugs: Identification Guide, Preventive Measures, and a Review of Treatment Protocols