I notice that you remove "as" from the original post. Both original sentences use "as compared to". I copy them here:
1. [Many people believe that cicadas live for a short period of time, but they actually live a long/longer life as compared to other insects.]
2. [This question is difficult/more difficult as compared to the previous one.]
But I also find such a sentence as follow from New York Times:
In the United States today, fewer than 500 babies are born with the
infection each year, as compared with nearly 2,000 four years ago.
(quotes:
[link]Are there any reson that "as" is added or removed?
Thanks