Do silver ladybugs eat plants

No, silver ladybugs (Olla v-nigrum) do not eat plants.

Specifically, the silver or ashy gray ladybirds are insectivores, which means that they eat insects. Many lady bird beetles eat soft-bodied bugs. The silver ladybird beetle is no exception in preying on aphids and on jumping plant lice, the latter of which also are called psyllids.