I think they do need a bit of a winter dormant period, so possibly keeping them consistently warm, such as growing indoors or in a greenhouse would do, might cause them to decline from not enough sleep. (don't we all?)
Mine come to life, and bloom anywhere from late March to early May here. Depends on how warm the springtime weather is. They put up fresh new leaves before the flower stems show up.
I've never seen any insect problems on mine, but of course they've been out there in the jungle all their lives, so I may not have noticed. But when I re-potted them recently, there were no bugs, or signs of anything. Then the day after I put the pots back out, the local bunny showed up and had to be dissuaded from nibbling on the Phaius leaves. (they're up on pedestals, out of reach of Peter now)