Chattanooga: Long journey

Despite warnings posted throughout the exhibit about their fragility, the inhabitants of the Tennessee Aquarium’s butterfly garden have survived diseases, parasites and journeys of up to 10,000 miles from around the world.

About three-fourths of the aquarium’s butterflies come from Costa Rican Entomological Supply (CRES) outside San Jose, Costa Rica, which distributes farm-raised butterflies from growers throughout the country.

The aquarium also purchases butterflies from England, Malaysia and Ecuador, though these shipments are smaller and less frequent than those from Costa Rica, said Dave Collins, the aquarium’s curator of forests.

1 ON THE FARM

Butterfly farmers raise butterfly eggs to the larval (caterpillar) stage in greenhouses where an adult breeding population is kept. “(Butterflies) need to lay their eggs on a specific species of plant, and their larvae can only feed on that species,” Dave Collins said. “Farmers collect the eggs, take them outside and place them on nursery-grown tracts of specific plants.” The plants, shown at left, are wrapped in a protective mesh to prevent caterpillars from escaping and to protect them from predators until they are ready to enter a pupal stage and form a chrysalis.

2 IN TRANSIT

All butterflies are shipped as chrysalises because they don’t eat and can remain dormant for several weeks during this stage. On Sundays and Mondays, farmers harvest the chrysalises and deliver them to distributors such as CRES, which then transport them by air to the United States.

3 PAPERS,

PLEASE

Imported live exotic animals are inspected at their port of entry by the U.S. Department of Agriculture, U.S. Fish and Wildlife Service and U.S. Customs and Border Protection. Shipments are checked against a list of species the aquarium is permitted to import.

“Fortunately, USDA is extremely helpful and supportive of the butterfly industry,” Mr. Collins said. “(It is) balancing the need to protect our native butterflies and flora from potential problems caused by imports with the value to our visitors.”

4 ARRIVAL

After passing border inspections, the chrysalises are delivered by truck to the aquarium by Wednesday or Thursday. A smaller weekly shipment also comes from one of the aquarium’s other suppliers.

5 QUARANTINE

To prevent the escape of exotic species into native ecosystems, USDA requires importers to have a completely isolated receiving room. Mechanisms to ensure this include:

An independent air supply Downward-aiming fans at doorways Steel mesh covers on drains Caulk sealing around the ceiling

“All this is not only to contain the butterflies but also, and maybe more importantly, to contain any parasites that come in on the pupae,” Mr. Collins said. Aquarists check the chrysalis for parasitic wasps and flies, as well as diseases. If any are found, the chrysalis and parasite are killed by submersion in alcohol, shown in the above photo.

6 EMERGENCE

Aquarium entomologists pin healthy chrysalises upside down in a viewing window by a piece of silk the chrysalis naturally produces. Most mature into adult butterflies within one to two weeks of arrival, but some species, such as the Kenyan green swallowtail butterfly, can take several months.

After emerging, the butterflies remain hanging upside down to allow their wings time to dry, a process that can take several hours.

7 SWEET RELEASE

At least twice a day, aquarists gather the newly emerged adults into a mesh-covered release cage and transport them to the butterfly garden. The butterflies live several weeks to a few months, depending on their species. The aquarium is not permitted to breed butterflies, and because adults only lay eggs on plants their larva will feed on, no host plants are used in the garden.