I think this question is better asked as "are there examples of prime SEQUENCES in nature?"
The fact that a starfish has 5 points, or that a sunflower has 23 petals or whatever, proves very little about primes in nature. It could be complete coincidence that the number happens to be prime.
What if starfish are found to have either 3, 5, or 7 points? Does that imply a prime sequence? Maybe its just something about odd numbers > 1.
The Cicada example definitely implies a prime sequence, not just a single number which happens to be prime.