Invertebrate Study

Saint Louis Zoo researchers are identifying the diverse species of invertebrates (insects, bugs and other spineless wonders) that use the various habitats (grasslands, forests, water) at the Saint Louis Zoo WildCare Park. They are especially focused on identifying pollinators, including a variety of bees and butterflies.

Important First Step

Identifying what species are present on the property is an important first step in making informed decisions about future property uses, including collection planning and management, native wildlife corridor management, habitat management and restoration, and educational program development in terms of property design and use.


In 2020, 23 species of butterflies and over 22 species of bees were identified. Some highlights include:

  • Zebra swallowtail butterfly
  • Monarch butterfly
  • Buckeye butterfly
  • American snout butterfly
  • Cloudless sulphur butterfly
  • Black and gold bumblebee
  • Two-spotted bumblebee
  • Brown belted bumblebee
  • Metallic green sweat bee
  • Norton's Alkali bee
    • This species is notable because it is a specialist on the very type of habitat present at the WildCare Park — Mississippi River and Missouri River bottomlands. Saint Louis Zoo entomologists (insect experts) hadn't seen this species before in person and were pleased to discover it recently.

One of the most interesting discoveries is the large number of aquatic invertebrates, including dragonflies, damselflies, stoneflies, dobsonflies and mayflies, which suggests that water quality in the WildCare Park ponds is good enough to support invertebrate life. At a black lighting night survey in summer 2020, caddisflies (moth-like insects as adults and aquatic in the larval stage), were present in huge numbers.

Scientists are also studying the quantity and diverse species of ticks present in this area, which will be helpful for animal health purposes when the North Campus animals eventually live on this land.

Scientific Methods

One of the ways scientists count and identify night flying insects is to use a light trap in a process known as black lighting. Using a UV light bulb, or blacklight, which the insects are attracted to, researchers are able to observe and collect the animals as they land on a white cloth sheet. Once recorded, the insects are released back into the night.

Once a month from April through October, observers walk transects, or sample areas, throughout the property's varying landscapes to identify certain species by straight observation (eyes or binoculars, or temporary hand/net collection) or by photography for later identification. Drag cloths are used to sample ticks.

The health, safety and psychological well-being of the animals included in this study are priorities for Zoo researchers. Only skilled personnel handle animals for species ID or health assessment purposes. These interactions are for the shortest amount of time possible and the animals are released back to their wild habitats after the necessary data collection is complete.


Missouri is home to over 470 species of bees with over 201 species found in the St. Louis area. In addition, there are at least 417 species of butterflies and moths known in Missouri. However, for most terrestrial and aquatic invertebrates the number of species is unknown.

Zoo Conservation Programs

See more about how the Zoo is helping invertebrates around the world:

How You Can Help