Emergence

By Chelsea Jandreau

Many of the summer insects we see do not suddenly appear as the fully formed adult versions we are likely to casually encounter. These insects, along with many amphibians and a few other animals, have life cycles that require us to look in an entirely different direction to find their younger forms. Instead of coming straight out of the egg or embryo into a smaller version of their adult selves, like most mammals and birds do, these animals begin their life in a larval phase, and many of them spend this phase underwater.

We often learn about these life cycles in school, sometimes in conjunction with metamorphosis, which is the process of an animal’s transformation through multiple distinct stages as they make their way from egg to larva, pupa, and adult. This topic often begins and ends with a couple major examples, notably the butterfly and the frog. A butterfly hatches out of the egg as a caterpillar until it eventually forms a chrysalis and later emerges as a butterfly. Tadpoles start out in the water and as they grow, their body slowly changes until they leave the water as a frog or toad. However, these are just two examples of a phenomenon found happening every day during the summer to a number of animals. 

Summer day camps have begun here at Audubon and with that means ample time spent outdoors exploring and making discoveries. Recently one such summer camp group was exploring animals that can fly, glide or soar, and so, armed with aerial nets, we went out into the fields and along the edges of ponds to search for flying insects.

We found flying beetles, crane flies, moths, a Monarch butterfly, and a variety of dragonflies. Dragonflies are quick and agile, which make them tricky to catch even with an aerial net, but we succeeded in catching a couple different species. Dragonflies and damselflies are common summer sights, but unless you have dipped into a pond looking for critters, you may not have seen their larval, or nymph, stage. A surprising number of flying insects start their life cycles underwater in ponds, and many of our day camp kids will discover some of these larvae during pond explorations throughout the course of the summer. 

As far as pond invertebrates go, dragonfly nymphs are generally an exciting find when taking out nets to collect pond critters with kids, and even adults. They are large and dynamic predators that can be a bit of a mystery the first time you see them as they don’t look exactly like their slender-bodied adult counterparts. 

An adult dragonfly will lay eggs on plant matter, such as plant stems or logs near the surface of the water. Some will go directly to the source and lay their eggs directly into the water. Within a few weeks the dragonfly nymphs will emerge and spend the first stage of their life underwater, anywhere from a few months to a few years, hunting pretty much anything that swims by and fits in their mouth. This includes other invertebrates, small fish, and even tadpoles. Dragonflies are impressive hunters from birth to death, but as larvae they have a killer adaptation that helps them catch their food. Their jaw is hinged and it can extend away from their body, quickly scooping up their prey, in a similar fashion to a human arm reaching out to catch something.

In reality, most dragonflies actually spend the majority of their life in this nymph stage underwater. They will molt several times as they grow larger until they reach their final molt where they climb out of the water and eventually emerge directly from their exoskeleton for the last time as a full adult dragonfly.

Dragonflies are a fascinating example of insect emergence from their aquatic larval stage to a terrestrial adult stage, but they are only one of many that follow this pattern. Mosquitoes start as small larva underwater, which is why areas with still water tend to be a more mosquito-heavy. Caddisflies, mayflies, and stoneflies (are you picking up on a theme?) are just a few other examples of insects that begin their life cycle underwater. So even though you might see those dragonflies, or a whole host of other flying critters zipping over the pond, remember that sometimes that is only part of the story. There is another stage of life hiding under the surface of the water.

Audubon Community Nature Center builds and nurtures connections between people and nature. ACNC is located just east of Route 62 between Warren and Jamestown. The trails are open from dawn to dusk and birds of prey can be viewed anytime the trails are open. The Nature Center is open from 10 a.m. until 4:30 p.m. daily except Sunday when it opens at 1 p.m. More information can be found online at auduboncnc.org or by calling (716) 569-2345. Chelsea Jandreau is a Nature Educator at Audubon Community Nature Center.