Insect Once Thought Extinct Bred at Zoo

It may not be Jurassic Park, but the San Diego Zoo entomology department received 300 eggs last weekend from a critically endangered stick insect.

The Lord Howe Island stick insect or tree lobster, thought extinct for over 80 years, was rediscovered in 2001 on an eroded remnant of a volcano called Ball’s Pyramid just off the coast of Australia.

The eggs arrived from Australia’s Melbourne Zoo and placed in 16-ounce containers filled with vermiculite, a soil additive that provides appropriate moisture for the egg’s development. The eggs will be kept in an off-exhibit area to hatch at a precise temperature and humidity.

"The rearing facility at the zoo is a very clean space," said  "The animals are restricted to that area because we want to make sure we have all best practices and that means no fear of cross-contamination with the other invertebrates in our collection. It's very hot, it's very humid, it's very much like Lord Howe Island."

The entomology department successfully hatched the insect in 2012, but the group didn’t thrive. A review by the animal care staff and horticulture team decided the insects needed special plants that were used the Melbourne Zoo programs, which were unavailable in North America at the time. Plans to hatch more eggs were put on hold until the zoo was able to raise enough of this plant to feed the insects.

Horticulture supervisor Seth Menser traveled to Australia in 2012 to bring back 100 cuttings of Melaleuca howeana, a shrub native only to Lord Howe Island and Ball’s Pyramid. The zoo now has over 150 plants growing in six different plots. This is expected to be the insects’ primary food source.

The eggs are expected to hatch in two weeks and are expected to grow to seven inches long.
Since the rediscovery of the insects, the Melbourne Zoo has had great success in their efforts to breed them.

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