Green Darner Dragonfly annual migratory cycle revealed for the first time ever

The study conducted by researchers in Baltimore County, published in Biology Letters, reveals the annual migratory cycle of the green darner dragonfly. Using stable hydrogen isotope analysis on wing samples from over 800 dragonflies collected over 140 years, the study found that it takes three generations to complete the cycle. The first generation migrates from the southern United States, Mexico, and the Caribbean to the upper Midwest between February and March, lays eggs, and dies. The second generation matures and migrates south, laying eggs upon arrival. The third generation does not migrate but lays eggs that restart the cycle the following spring.

What is the significance of Baltimore County in relation to the annual migratory cycle?

How many generations of green darners are required to complete an annual migratory cycle?

During which months do dragonflies typically begin their migration from the southern United States?

What happens to the second generation of dragonflies after they reach maturity?

What is the fate of the third generation of green darners in the migratory cycle?