Speckled Sussex stopped laying

[Strykester]

I’ve got a speckled Sussex pullet who is about 6 1/2 month old (I got her the last week of April when she was around a week old). She began laying very infrequently in late August with maybe an egg every 3-4 days, but she hasn’t laid for the last month and her comb looks pale and slightly chapped. At first I was contributing it to the loss of daylight and possibly due to the unseasonable weather here in Pittsburgh (30 degree high temperature swings in 2-3 days) but now I’m wondering if there is something more. I don’t think it’s lice or mites and she’s shown no signs of scratching or being uncomfortable that I’ve noticed. I’ve seen her eat and drink, and she’s not being picked on or tormented the rest of the flock. I’ve attached a few pictures and any input would be greatly appreciated.

 

[Yardfulla poopers]

I would try giving her a thorough exam if possible just to make sure there isn't something you are missing. Check for mites (I know you said you don't think she has them, but just to make sure), check her vent, etc. Maybe also try giving some poultry vitamin.
What feed are they on?

 

[Strykester]

I just stopped at my local feed store and talked to a gentleman who is a poultry expert with the PA department of agriculture. He told me that my pullet is actually an Ancona, and not a speckled Sussex. After looking over some pictures, he seems to think that the stop is most likely caused by the significantly reduced daylight. I bought the supplies to de-mite the coop and run as a precautionary measure. I’ve got an appointment with the vet tomorrow, so fingers crossed it’s just a quirk of my pullet and all will be well. They’re on Purinas flock grower, but Tori seems to be low on the pecking order. I watch her eat when the rest of the flock is wandering around, but when another pullet comes to the food, she scatters. But again today she was eating and drinking, I set up multiple food dishes so she could eat on her own. Apparently this isn’t super uncommon behavior for an Ancona, hoping that’s the case. I appreciate your input and guidance.

 

[aart]

I bought the supplies to de-mite the coop and run as a precautionary measure.

Do not use this unless you are sure you have mites.
Preventative insecticide use can cause resistance.

Have you checked them over real well for mites and/or lice?

Google images of lice/mites and their eggs before the inspection so you'll know what you're looking for.

Part the feathers right down to the skin around vent, head/neck and under wings.

Best done well after dark with a strong flashlight/headlight, easier to 'catch' bird and also to check for the mites that live in structure and only come out at night to feed off roosting birds.

Wipe a white paper towel along the underside of roost to look for red smears(smashed well fed mites).

Good post about mite ID by Lady McCamley:
https://www.backyardchickens.com/threads/my-chicken-has-mites-now-what.1273674/page-2#post-20483008