| Danaus plexippus (Linnaeus, 1758) |
| Status: Common breeding migrant |
| Flight Period(s): There are at least two broods. Nebraska records are from 7 April – 24 October. |
| Range: This butterfly overwinters in coastal California and in Mexico (in mountainous areas south of Mexico City). From these overwintering sites females and subsequent generations migrate north as far north as central Canada. The Monarch is found statewide in Nebraska. |
| Larval Hostplant(s): Milkweeds (Asclepius species) |
| Overwinter: The Monarch does not overwinter in Nebraska. |
| Commentary/Habitat: The colorful Monarch is unique in that it is the most recognized butterfly migrant in North America. While many southern butterflies stray north, very few have any return flight south, and none match the Monarch’s consistant southern migration in autumn. In Nebraska this migration normally peaks in late August to mid-September. During this migration mass roostings often occur when, near evening, a tree is selected in which the migrants gather in large numbers to pass the night. The southern migration destination has become genetically implanted, as no butterfly makes the same trip twice. Butterflies flying south in the fall are the children or grandchildren (or more) of the last butterflies to have made the southern migration. Milkweeds, on which Monarch caterpillars feed, contain varying amounts of poisonous glycosides that the caterpillars ingest and retain as adult butterflies. Butterflies resulting from caterpillars ingesting high amounts of glycosides are distasteful to predators, and afford protection to adults with lesser amounts as birds having encountered a poisonous adult avoid the species altogether. This is effective as long as the number of poisonous adults remains at sufficient levels to discourage predation. In most studies well over half of adults tested contained enough glycosides to be distasteful. Thus their bright coloration becomes a virtual advertisement that the species is poisonous. The palatable Viceroy has taken advantage of this by situation by evolving a color pattern very similar to that of the Monarch. |
| Similar Species: Viceroys and Queens |
