Nymph is the generic term for any non-adult regardless of size.
If they haven't made the final molt to adulthood, they are nymphs.
That being said, 1 - 1 1/8" nymphs are still several molts away from adulthood.
At that size expect it to take between 1-2 months for them to all reach adulthood
and start breeding. (Then add in ~30 days gestation time before you see your first babies).
Buying mixed sets (ie unsexed nymphs, just thrown in together) of nymphs is often cheaper
than buying direct breeding age females (adult males are usually so cheap and you need so few
that they can be safely ignored in your total price -- expect to add a couple of dollars for the males
you'd need). You can usually get several hundred nymphs for the same price as 30-50 adult females.
However, going with nymphs means it takes that much longer before your colony is fully established.
If you can wait for them, then by all means save money and just buy a bunch of large nymphs.
If you want your colony up and running as fast as possible, then you'll have to invest in a good quantity
of adult females and a few adult males (you want around 5-6 females per 1 male). Exactly how many
depends on how many feeders per month you need and how long you're willing to let the colony grow
before you feed from it.
