200 Years. 200 Stories. Story
129: “The World’s Rarest Insect
Two of the five land lobsters (Dryococelus australis) specimens in the Academy’s Entomology Collection. The male shown at the top is distinguished by its enlarged femora (thigh-like segment on the hind legs). Females, like the one shown at the bottom, are larger than the males. In this case, the female is 4.4 inches long while the male measures 3.9 inches. Land lobsters, also known as “sausage insects,” are a species of phasmids (stick insects). Photos by J. D. Weintraub.
The World’s Rarest Insect
The Academy’s Entomology Collection contains five specimens of the world’s rarest and most endangered insect, the land lobster (Dryococelus australis). The specimens, which came to the Academy in an exchange with the Australian Museum, were probably collected on Lord Howe Island in 1916 by naturalist P.R. Pedley. The insects were endemic to the island (native to the island but found nowhere else). They were also quite common.
Lord Howe Island is a small and mountainous island located several hundred miles east of the Australian mainland. The steamship SS Makambo supplied the islanders with their main link to the outside world. Unfortunately, that ship ran aground in 1918, and the escaping rats quickly overran the island and decimated its native wildlife. Within a few years, several species of endemic birds were driven to extinction. So too, presumably, was the land lobster.
Remarkably, these insects were rediscovered in 2001 on Ball’s Pyramid, a rugged and largely barren volcanic islet located 14 miles from Lord Howe Island. It was a precarious toehold. Ball’s Pyramid covers only one-eighth of a square mile, and the land lobsters were found only in a small patch of shrubs growing on a single rock ledge. Australian scientists transferred two adult pairs from this tiny refuge to a captive breeding program in the Melbourne Zoo. They plan to reintroduce the progeny to Lord Howe Island once the rats have been eradicated.