I believe people in AZ use an Imidacloprid soil drench to prevent weevil damage, applied just before the weevils become active. Bayer Advanced 12 month Tree and Shrub Protectant is commonly used. It will kill bees who visit the flowers, so should be discontinued as the plant gets close to blooming size. Another drawback is that Imidacloprid can kill off predators of spider mites, causing an explosion in population of that pest, so one must be alert to any spider mite issues. It's also important to IMMEDIATELY remove any agave infected with weevils,

Here ya go...

Here is a link that might be useful: Agave Snout Weevil

Thanks to both of you.