DNA con­firms is­land in­sect not ex­tinct after all

Rats had been blamed for wip­ing out species

Las Vegas Review-Journal (Sunday) - - SCIENCE - By Will Dun­ham

WASH­ING­TON — When black rats in­vaded Lord Howe Is­land after the 1918 wreck of the steamship Makambo, they wiped out nu­mer­ous na­tive species on the small Aus­tralian isle in the Tas­man Sea in­clud­ing a big, flight­less in­sect that re­sem­bled a stick.

But the Lord Howe Is­land stick in­sect, once de­clared ex­tinct, still lives. Sci­en­tists said Thurs­day DNA anal­y­sis of mu­seum spec­i­mens of the bug and a sim­i­lar-look­ing one from an in­hos­pitable volcanic out­crop called Ball’s Pyra­mid 14 miles away con­firmed they are the same species.

The find­ing could help pave the way for its rein­tro­duc­tion in the com­ing years.

“The Lord Howe Is­land stick in­sect has be­come em­blem­atic of the fragility of is­land ecosys­tems. Un­like most sto­ries in­volv­ing ex­tinc­tion, this one gives us a unique sec­ond chance,” said evo­lu­tion­ary bi­ol­o­gist Alexan­der Mikheyev of the Ok­i­nawa In­sti­tute of Sci­ence and Tech­nol­ogy Grad­u­ate Univer­sity in Ja­pan.

The glossy-black in­sect that grow up to six inches in length is nick­named the “land lob­ster.” Other stick­in­sects are found around the world, so named be­cause their ap­pear­ance lets them blend in with trees and bushes to evade preda­tors. As adults, the win­g­less Lord Howe Is­land stick in­sects shel­ter in trees dur­ing day­time and come out at night to eat shrub­bery. The bright­green ba­bies are ac­tive dur­ing day­time.

By about 1930, they had van­ished on Lord Howe Is­land, which was thought to be their only home. There were no land-dwelling mam­mals there when the rats ar­rived, and they also van­quished five bird species and 12 other in­sect species.

A rock-climb­ing ranger made a cu­ri­ous dis­cov­ery in 2001 on Ball’s Pyra­mid: a sim­i­lar-look­ing in­sect. Since then, cap­tive breed­ing pro­grams have be­gun at the Mel­bourne Zoo and else­where.

Be­cause of cer­tain dif­fer­ences be­tween the Ball’s Pyra­mid in­sects and the Lord Howe Is­land in­sect mu­seum spec­i­mens, there was some ques­tion about whether they were the same species.

“We found what every­one hoped to find, that de­spite some sig­nif­i­cant mor­pho­log­i­cal dif­fer­ences, th­ese are in­deed the same species,” said Mikheyev, who led the re­search pub­lished in the jour­nal Cur­rent Bi­ol­ogy.

Of­fi­cials are plan­ning a pro­gram to erad­i­cate the invasive rats on Lord Howe Is­land, which could al­low the stick in­sects to re­turn.

“I imag­ine that maybe a decade from now, peo­ple will travel to Lord Howe Is­land and take night walks, hop­ing to glimpse this in­sect,” Mikheyev said. “In maybe 20 years, they could be­come a ubiq­ui­tous sight.”

Reuters

An adult fe­male Dry­oco­celus aus­tralis, also known as the Lord Howe Is­land stick in­sect, which was once de­clared ex­tinct.

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