I can confirm the above. Your beardie will have no problem eating them. He'll likely woof them down in no time.
Expect some green messy smiles !
Tip if the silkworms are part of mixed live feeding menu , weigh the worm and the other staple bugs (ie crickets) , you'll find a medium sized silkworm (1.5- 2" long) is about as heavy as 4-6 medium crickets , and so 3 to 4 medium silkworms is equiv to 10 - 12 medium crickets and will a very good meal for a 3 -5 month old beardie.
One or 2 large silkworms will really fill him up.