Why is cuckoo spit so called when it has nothing to do with a cuckoo?

The name "cuckoo spit" comes from the appearance of the foamy mass that surrounds the nymphs of certain froghopper insects. This froth, which is produced by the nymphs to protect themselves from predators and environmental conditions, resembles the saliva or "spit" of a cuckoo bird. Despite the common name, there is no direct connection between cuckoo birds and the frothy substance associated with froghopper nymphs.