Black Death - Nuclear Polyhedrosis Virus (NPV) on Monarch Caterpillar (Danaus plexippus)

This virus enters the nucleus of infected cells and reproduces until the cell begins to produce crystals in the fluids of its host. The host becomes swollen with virus-containing fluid, turns black, and dies. Eventually, the caterpillar's skin will split open and virus particles will spew everywhere.

Habitat: Infected monarch caterpillar (Danaus plexippus) on milkweed in a meadow