Hine's emerald dragonflies were once thought to be extinct, but wildlife officials recently raised many of the winged animals and are releasing them in a wildlife refuge in Illinois. There, environmentalists hope the insects will join with an existing small group of the endangered creatures. 

Dragonfly eggs were originally collected from an insect in southwestern Wisconsin and sent to the University of South Dakota. There, the tiny creatures were raised for four to five years, preparing for their planned mission to repopulate Illinois. 

Environmentalists believe the population of these endangered dragonflies in the region numbers no more than 320 individuals. This restocking is planning to introduce 20 more individuals to the local population. 

In the wild, just around 1 percent of all dragonfly eggs survive long enough to make it into adulthood. Under laboratory conditions, this survival rate greatly increases up to 10 or 20 percent, making repopulating the creatures feasible. 

The Hine's emerald dragonfly, a member of the Corduliidae family, is extremely rare around the globe. In the middle of the 20th century, biologists believed that the species had disappeared from the globe. However, a single member of the species was discovered in 1988, rewriting what was known of the animals. The largest group of breeding individuals currently resides in Door County, Wis. The creatures may also be found in small numbers in Baileys Harbor, Wis., parts of Missouri and Ontario, as well as northern Michigan. 

"Adults lay their eggs in small streams in fens and sedge meadows. After hatching, the aquatic larvae spend up to five years in wetlands before completely maturing and emerging as adult dragonflies," the U.S. Fish and Wildlife Service reports on its website.  

Adults only live four to five weeks between June and August, before they reproduce and die off. 

Eggs were selected from a dragonfly in Wisconsin due to the fact that the animals in that area have a great deal of genetic diversity, as does the population in Illinois. This could raise the chances of the creatures surviving over time. 

"You may have lots of numbers, but if they're genetically almost identical, that means there's not as much ability to resist something like a disease that comes along or that they just won't have as much flexibility in terms of quick responses to things like change in conditions," Daniel Soluk from the University of South Dakota, leader of the study, said. 

Hine's emerald dragonflies are the only species of Odonata to be listed on the U.S. Federal List of Endangered Species since being granted that classification in January 1995.