Cockroaches Eating Cantaloupe
Can you send us a photo of the insects you are seeing? Cockroaches aren't typically a pest of cantaloupe. A photo of the insect(s) will help us determine what it is and what's going on. You can attach up to three photos to this reply.
Cockroaches are not a common pest of our fruits and vegetables, but they will take advantage of over-ripe or rotting fruit. It looks like this cantaloupe falls into that category.
The constant wet weather could play a role, but in general, try picking earlier.
Here is our page on growing muskmelons, which includes most common problems:
This is interesting. In this case, the cantaloupe was not quite ripe when they began to eat it. It has now been sitting there exposed to the elements and the cockroaches for over a week, which is why the cantaloupe is now rotting.
I look forward to looking at the suggestions for growing muskmelons.