Q.What are the hundreds of tiny white “eggs” on my Holly
Just noticed the plant getting brown leaves and black stems but didn’t see any insects. Also some on a tomato plant. Thank you. Dottie
The most likely answer is that the eggs are actually scale of some kind. Scale are small insects that are covered with a shell, and fix themselves to the plant to suck its juice -- kind of like vampire oysters. You can spray them with neem oil or soap solution. This article has more information: https://www.gardeningknowhow.com/plant-problems/pests/scale-bug-how-to-control-plant-scale.htm
Just be sure to use your spray at weekly intervals for four weeks.