In raising my beetles, I've noticed a few things I think could be really nice to add to the game. Beetles do take a backseat to lions but I still think they deserve a few little things, too. This led me to the following ideas:

Growth Supplement/Bait

The idea behind Growth Supplement or Bait is that it improves the chance of your beetle succeeding during training. Doesn't guarantee it, doesn't increase the amount of stats your beetle can get - simply improves its chance of succeeding. I think it'd be a good idea for it to be a multi-use item - perhaps something like a food bundle-type image, reflecting various types of foods beetles like since not all like nomming on leaves. Of course the aesthetic choice scarcely matters!

I figured this would be available at Beetle Grounds or during events, sometimes single uses found during explore? With a message like "You find a mostly in-tact food morsel your beetles might like. You gather it to take home with you" or something!

Instant-birth Item

We all have those days where we forget to breed their beetles on the last day or their beetles have mismatched breeding dates - this can result in you breeding too late. So I think having an instant-birth item would be a real asset, it could avoid losing lines due to forgetting, especially when beetles only get 2 chances to breed for their lifetime - those two breedings really count! (Especially at the risk of getting only 1 egg a clutch) Either Oasis item or in Monkey Business.

Pheromone Something-or-other

My thoughts are that there could be a pheromone item (or some other enticing item) that makes larvae in explore less likely to bite you and easier to capture. Or perhaps makes them more common to see? (Such as catnip/snake scent). I imagine this would be available from Whack-a-snake as they are.

Honeycomb Equivalent

Their stats are fairly small (and probably are meant to be) but I think it'd be a good idea to have a stat-rich food available to be fed to larvae! Of course not bearing as many stats, I think even just an improved chance of +1 would be fair. Definitely an event item - complete with expiration.