Cooperative Extension Service Communications and Technology Department 3354 1000 E. University Ave. Laramie, WY 82071 (307) 766-6342 • fax (307) 766-3998 • www.uwyo.edu

 

For Immediate Release

Story Contact:

Alex Latchininsky

(307) 766-2298

 

Contact: Steven L. Miller, Senior Editor

Phone: (307) 766-6342

E-mail: slmiller@uwyo.edu

Archived News Site www.uwyo.edu/agadmin/news/news.htm

 

Date: Nov. 16, 2006

 

UW entomologist surveys Hawaiian island for grasshopper damage

 

By Tiffany Schaffner

UW College of Agriculture Student Intern

 

 

A University of Wyoming grasshopper expert has helped determine grasshoppers that had endangered several endemic species on the small, uninhabited Hawaiian island of Nihoa in 2004 no longer pose a threat.

However, that could change depending upon climatic conditions, noted Alex Latchininsky, an extension entomologist and assistant professor in the University of Wyoming’s Department of Renewable Resources.

Latchininsky spent 11 days on the island in October.

“The goal of the expedition was to assess the current biodiversity situation on the island and to propose any mitigation measures to reduce the possible negative impact from the grasshoppers,” said Latchininsky.     

            Latchininsky and Jeff Lockwood, a noted entomologist and now a professor in the Department of Philosophy at UW, were asked by the U.S. Department of Agriculture and U.S. Fish & Wildlife Service (USFWS) to travel to Hawaii in April 2004 to meet with 10 other consultants examining events on Nihoa. The team discussed the grasshopper invasion and its possible effects on native habitat.

Nihoa Island, about 250 miles from the main Hawaiian Islands, is part of a chain extending northwest.  The island has abundant life. Seventy-two terrestrial arthropods, including giant crickets, and two endemic songbirds, the Nihoa finch and Nihoa millerbird, are found only on Nihoa, according to the Northwestern Hawaiian Islands Multi-Agency Education Project (http://www.hawaiianatolls.org/about/nihoa.php).

              “In 2004, grasshoppers ravaged the vegetation on Nihoa Island,” said Latchininsky.  “There were an estimated 6 million grasshoppers destroying vegetation at a rate of about 1,200 pounds per day, shearing off all the green.” 

            The entire island ecosystem became at-risk.

            The grasshopper of concern is native to Central America and is found on the main Hawaiian Islands, although it is not native there either and is a threat to island ecosystems.  The insects apparently hopped wind currents and flew the 250 miles to Nihoa. 

When Latchininsky and three other members of the team visited Nihoa last month, the damage by the grasshoppers was not as visible as two years ago.  Latchininsky explained that grasshoppers are not a problem now because abundant rains contributed to developing a lush vegetation cover on the island.  Yet Latchininsky estimates up to 12,000 adult grasshoppers are present on the island. 

Their potential for damage may dramatically increase under drought conditions.

“There are no sources of fresh water on this tiny island, so all plants are entirely dependent on atmospheric precipitation, which can be very erratic.  Sometimes, there is no rain for several months, which creates a severe drought,” explained Latchininsky. 

Drought conditions are favorable for grasshoppers because they develop faster and avoid diseases associated with moisture, he said. Grasshoppers become more numerous and their impact on the meager vegetation becomes more pronounced. 

That was the case in 2004 when, because of a severe drought, only the palm trees maintained some foliage but all the grassland vegetation was decimated by both drought and the grasshoppers, noted Latchininsky.  

But last month, the island was relatively green, the vegetation was lush, and grasshopper damage was not very pronounced.  “It is necessary to keep an eye on the situation and continue regular surveys of the island’s biodiversity,” said Latchininsky.

Erosion of the dormant volcanic peak has created steep slopes on the island. Getting around the island was difficult because the terrain was so steep, said Latchininsky.

“There is not a single flat space,” noted Latchininsky. The island, which stretches about 1,500 yards east and west and varies from 300 yards to 1,000 yards wide, has an area of only 156 acres.  The craggy mass of rock hosting a menagerie of rare species of birds, plants, snails and arthropods is under the Hawaiian Islands National Wildlife Refuge supervision.

The USFWS prohibits visitation to protect the island’s ecosystem. Only four researchers at a time are allowed under special permit, and their belongings must be sterilized, said Latchininsky. 

            On the Web: www.uwyo.edu/UWRENEWABLE/Faculty/A_Latchininsky.asp

###