I always wondered if he is a Bug-type specialist, since he have three Bug-Type in his team.
After the B2W2 release, I think it is even more likely now.
The reason for this is within the spoiler, for those who did not play the new games yet:
Also, Steven was Steel Type specialist, but he had only three Steel Pokémon in his team. One can argue that he is not, since the only Bug in his PWT team is Volcarona, but we don't know for sure if the feature is canon.
Well, the main reason I am creating this thread is because there are people who don't agree with Alder being a Bug Master and I want to see other people opinions about this subject.
So, what you think??