@Lordie; No, it’s not white worm. Looks like lacquer (clear coat) peel on one of the spokes on the black painted / powder coated section. White worm affects the diamond cut areas of the wheel.
@AmbushReality; always annoying when you discover something like this. If the lacquer peels and lifts off painted / powder coated surfaces on an alloy wheel, it maybe an indication that the wheel has previously been refurbished. Even if you’ve owned your car from new and none of the wheels have been refurbished during your ownership, there’s a chance it was damaged and refurbished prior to you collecting your car when new. Damage to brand new cars after leaving the factory and before the customer takes delivery does happen.
The wheel cleaner you’ve been using shouldn’t have caused it as Bilt Hamber Auto Wheel is ph neutral, although using a pressure washer on your wheels could cause lacquer lift if they’ve had a substandard refurb if the pressure washer lance is held too close to the wheel.
You’re probably looking at a cost of around £90-£100 plus VAT for a good quality refurb.