As nouns the difference between backworm and blackworm
is that backworm is a disease of hawks; filanders while blackworm is an oligochaete, (taxlink), found in shallow water marshes, ponds, and swamps in north america and europe, feeding on microorganisms and organic material.
blackworm
English
Noun
(
en noun)
An oligochaete, (taxlink), found in shallow water marshes, ponds, and swamps in North America and Europe, feeding on microorganisms and organic material.