New research reveals dragonfly annual migration cycle
- 5 years ago
BALTIMORE, MARYLAND — A team from the University of Maryland Baltimore County is the first to determine the annual migratory cycle of the green darner dragonfly.
According to the paper published in the journal Biology Letters, researchers employed stable-hydrogen isotope analysis on wing samples of more than 800 dragonflies from eight different countries spanning 140 years.
The wings analyzed were from specimens caught in the wild and from specimens preserved in museums.
The researchers found it takes three generations of green darners to complete an annual migratory cycle.
The first migration occurs between February and March. Dragonflies depart from southern United States, Mexico and the Caribbean by May they reach the upper Midwest. The first generation lays its eggs there and dies.
Dragonflies from the second generation head South again once they reach maturity and deposits another batch of eggs when they arrive at their destination.
The third and last generation does not migrate but produces another batch of eggs that will restart the cycle once again the following spring.
Researchers have not yet understood how migratory insects know what path to take during their migration cycles. Although climate change may pose a threat to this natural process.
Researchers participating in the study stated, “further research is needed to determine how a changing climate may alter the migratory schedules and annual cycle of dragonflies and other migratory insects.”
SOURCES:
https://royalsocietypublishing.org/doi/10.1098/rsbl.2018.0741
https://www.smithsonianmag.com/smart-news/dragonfly-undertakes-epic-multi-generational-migration-each-year-180971190/
According to the paper published in the journal Biology Letters, researchers employed stable-hydrogen isotope analysis on wing samples of more than 800 dragonflies from eight different countries spanning 140 years.
The wings analyzed were from specimens caught in the wild and from specimens preserved in museums.
The researchers found it takes three generations of green darners to complete an annual migratory cycle.
The first migration occurs between February and March. Dragonflies depart from southern United States, Mexico and the Caribbean by May they reach the upper Midwest. The first generation lays its eggs there and dies.
Dragonflies from the second generation head South again once they reach maturity and deposits another batch of eggs when they arrive at their destination.
The third and last generation does not migrate but produces another batch of eggs that will restart the cycle once again the following spring.
Researchers have not yet understood how migratory insects know what path to take during their migration cycles. Although climate change may pose a threat to this natural process.
Researchers participating in the study stated, “further research is needed to determine how a changing climate may alter the migratory schedules and annual cycle of dragonflies and other migratory insects.”
SOURCES:
https://royalsocietypublishing.org/doi/10.1098/rsbl.2018.0741
https://www.smithsonianmag.com/smart-news/dragonfly-undertakes-epic-multi-generational-migration-each-year-180971190/