I disagree that this needs a increase cast cost.
i think 2/2 for 2
and 3/4 for 3
seems fine.
you gotta look at what your passing up in the element.
Wyrm a potential 10 damage creature or elite firefly even is 4/2. a 2/2 or 3/4 arnt exactly devastating stats.
Alarms a reactive ability (like web) meaning its pretty much useless unless your opponent is using particular cards. It also doesnt really have much combo potential. I dont really view it as needing to add to cast cost.
Ill add that i like the card and simple ability creatures like this would add dynamic and diversity to the game. Oh and a generic name like song bird might be more suiting and more universally known.