Ok, a brief look over the APHIS database shows loquat on the NAPPRA list.
RIP
Basically, it's illegal to import, period. To import it legally, you'd need to apply to the USDA to get it delisted, and if they accept and delisted it, you'd then need to start the import permit process. But without a market access request, you won't get it delisted, and even so, the USDA will need to develope a pest risk analysis. Only when that PRA is complete and only if the results are satisfactory will the USDA delist the species and allow you to proceed with the import application, pest quarantine, etc.
That's my layman understanding anyway, I'm no lawyer though.