Suddenly, no eggs

[ambabya]

I have 3 laying hens who are all just over a year old. About a week ago, the Wyandotte just stopped laying. She isn't molting and I don't see any mites or anything like that. Ideas? Should I be worried?

My Maran hen looks like she is molting just around her fanny but till laying fine. EE looks/acts/lays fine as well.

I looked up the "usual suspects" and nothing hits home.
Generally, your answers are:

Decreasing day length
Molt
Broodiness
Flock health
Age
Poor nutrition
Stress