What you are observing has nothing to do with the Asian Beetles. You are observing what is termed "White Droplet Syndrome". Besides raspberries, it is also seen in other similar berries such as blackberries. A droplet is the single, individual unit in a single berry. It has been estimated that over 50 droplets can comprise a single berry. This condition is not caused by any fungus, bacteria, virus, or insect pest. It is merely a physiological response to intense and direct sunlight. For this reason it is also considered a form of sun scald. It typically does not affect the taste of the berry and is harmless to humans. I suspect that the orientation of individual berries toward the sun will determine which droplets turn white. Presumably those droplets most exposed to sun will become discolored. This would explain why you would not see this in all berries and that the extent of this discoloration will vary from berry to berry.

The following two sites will provide further information:

https://www.gardeningknowhow.com/edible/fruits/raspberry/white-drupelet-syndrome.htm

https://hortnews.extension.iastate.edu/faq/parts-berries-my-red-raspberries-are-white-color-why

Thanks for the question.