It’s definitely enough SHB to cause concern. How long as the cloth and Apithor been in there? It sounds like you may have a pretty decent infestation, hoping you got in early enough with the trap.
What is the general hive health like? It sounds like the colony is heaving trouble managing the SHB.
If you hold the Apithor up to the light, can you see any SHB in the ‘tunnels’?