American Snout Libytheana carinenta

Here's something remarkable: when these butterflies decide to migrate, newspapers in Texas and Mexico treat it as major news. Population eruptions are so massive and dramatic that migration waves become region-wide events worth reporting. The caterpillars are extremely specialized feeders on hackberry trees (Celtis species), where females lay eggs singly on the leaves. This complete dependence on a single plant species means each generation's success is entirely tied to where hackberry trees flourish.