Today I found a larva in my banana. My first reaction was not unlike most any other's: ew. But the entomologist in me quickly took over, so my "ew" lent itself to curiosity, amusement, and even flattery...it did choose my banana, after all.
Never having found a larva in a banana, I think I'll rear it out to an adult. It is some sort of moth (order Lepidoptera). Identifying larvae to their order, such as beetle (order Coleoptera), fly (order Diptera), etc.) is easy based on features like the prolegs, body shape, and head. But beyond that it gets dicey, and even accomplished entomologists simply resort to rearing out a larva to the adult stage, at which point wing venation is used to for more specific ID (genus or species level).
The same is true for you...if you find a larva somewhere unexpected and your curiosity outweighs the gross factor, rear it out! Then you can get help with a more specific ID, which will help you learn more about it and allow you to modify the environment so as to deter the critter from returning (as in the case of pantry pests) or encourage it (as in the case of garden beneficials). Keep your rearing environment similar to the conditions in which you found the larva; pay attention to humidity, light level, food source, and temperature. In this case, I simply left the little guy in the banana, folded the peel back over it, and put the whole thing in a terrarium placed away from sunlight (similar conditions to my kitchen cupboard). In 1-2 weeks, I will be the proud momma of an adult Lepidoptera.