Older Hens with young hens

[Lucy chick]

I have 5 black australorps that are 4 & 5 years old. I also have 4 buff Orpingtons that are 1 1/2 years old. For the past 3 weeks I have been getting 1 egg a week. Could the lack of the older birds laying eggs cause the younger ones to not lay?

 

[sourland]

The combination of shortening day length and a possible molt are causing the younger birds to take a break from laying.