Protocol to sequence markers from pollen grains carried by long-range migratory butterflies using metabarcoding.

Molecular identification of pollen carried by insects informs about their history of visited plants. For migratory butterflies, it can be used to trace long-range movements enduring days of flight over thousands of kilometers. Here, we present a protocol to (1) isolate pollen grains from butterfly bodies and (2) prepare metabarcoding libraries for their identification using the internal transcribed spacer 2 fragment, a common barcode used to identify plants.

Pollen metabarcoding reveals the origin and multigenerational migratory pathway of an intercontinental-scale butterfly outbreak.

Migratory insects may move in large numbers, even surpassing migratory vertebrates in biomass. Long-distance migratory insects complete annual cycles through multiple generations, with each generation's reproductive success linked to the resources available at different breeding grounds. Climatic anomalies in these grounds are presumed to trigger rapid population outbreaks.