Oeda sp. -- a magnificent oddity.

They are only related (in the sense) that they belong to the same insect order Homoptera.

The lanternflies (Fulgoridae) and treehoppers (Membracidae) are each distinct families within the order.

There are of course MANY other families of various plant hoppers with each broken down into its respective family.

I suppose one could say that one unique aspect which SOME lanternflies and SOME treehoppers share is the inexplicable reason why some species have evolved to an evolutionary extreme.

Membracid specialists have learned over the years that treehoppers are actually very good communicators. They have picked up sound waves using delicate instruments to record the noises which groups of these creatures make but, are inaudible to the human ear.

Some specialists, I believe have suggested that on some of the more elaborate exotic species which possess "hollow-ness of the pronotum"; they may be using this "empty helmet on their head and back" to enhance (and perhaps) focus the sound waves to communicate amongst themselves. Simply put, these adornments MAY serve as sound resonating chambers !

That certainly sounds like a plausible reason to me for such an extreme appearance in some of the species.

Perhaps, among some of the more extreme lanternfly species the same thing may be going on as well; though I have not heard or read of any similar experiments conducted -- as on treehoppers !

I would only say that evolution in its many varied aspects shows up in many ways on creatures both big and small.

The creatures do not have to necessarily be related nor does there have to be some evolutionary connection.

Evolution of a successful process in nature is in place for the success of a species. I believe, that environment and probably a host of other contributing factors help to bring out certain aspects of this process to aid species for their survival.

Cetaceans in their environment can certainly use a "sound resonating chamber" in the open ocean to communicate short and long distances since sound travels so well in water. Here the very environment dictates or (even mandates) this aspect of evolution being present.

So perhaps, in the realm of insects many evolutionary processes abound because of the many varied environments and niches which insects occupy.

As you can tell; evolution has held a long fascination for me. The more we as humans learn of it the more intriguing it becomes...

Thank you Adam indeed.

That is exactly the term I was searching for (in my mind) during my explanation following 58Chevy's question.

Convergent evolution hits this topic right on the head.