I grow citrus trees outside in summer and in a greenhouse in winter in Washington state. I found this scale? on the stems of two trees. They are white with regular tan spots, a hard shell and look like a tortoise. They snap off with your fingernail. Anyone know what they are? Will they be killed with neem oil?
CLOSED: Citrus Scale?
It's a wax scale; likely in the genus Ceroplastes - see http://nathistoc.bio.uci.edu/hemipt/DSC_8594b.jpg for an example. See https://www.planetnatural.com/pest-problem-solver/houseplant-pests/scale-control/ for some control suggestions.