Invasive cockroach found in NYC can take the cold

The High Line, a park that turned a dilapidated stretch of elevated railway on Manhattan's West Side into one of New York's newest tourist attractions, may have brought a different kind of visitor: a cockroach that can withstand harsh winter cold and never seen before in the U.S.

Rutgers University insect biologists Jessica Ware and Dominic Evangelista said the species Periplaneta japonica is well documented in Asia but was never confirmed in the United States until now. The scientists, whose findings were published in the Journal of Economic Entomology, say it is too soon to predict the impact but that there is probably little cause for concern.

"Because this species is very similar to cockroach species that already exist in the urban environment," Evangelista said, "they likely will compete with each other for space and for food."

That competition, Ware said, will likely keep the population low, "because more time and energy spent competing means less time and energy to devote to reproduction."

Michael Scharf, a professor of urban entomology at Purdue University, said the discovery is something to monitor.

"To be truly invasive, a species has to move in and take over and out-compete a native species," he said. "There's no evidence of that, but that doesn't mean we shouldn't be concerned about it."

The newcomer was first spotted in New York in 2012, by an exterminator working on the High Line.

The scientists suspect the little critter was likely a stowaway in the soil of ornamental plants used to adorn the park. "Many nurseries in the United States have some native plants and some imported plants," Ware said. "It's not a far stretch to picture that that is the source."

High Line said in a statement it sources its plants through mostly northeastern U.S. nurseries, which go through USDA inspections, and that no issues were raised with them.

"Our team of experts will continue to keep an eye on it," the statement said. The statement said High Line does not believe the insect is having a negative impact on the park.

Periplaneta japonica has special powers not seen in the local roach population: It can survive outdoors in the freezing cold.

"There has been some confirmation that it does very well in cold climates, so it is very conceivable that it could live outdoors during winter in New York," Ware said. "I could imagine japonica being outside and walking around, though I don't know how well it would do in dirty New York snow."

The likelihood that the new species will mate with the locals to create a hybrid super-roach is slim.

"The male and female genitalia fit together like a lock and key, and that differs by species," Evangelista says. "So we assume that one won't fit the other."