Posted on: Sunday, September 15, 2002

Maui mouse infestation in apparent decline

By Christie Wilson
Advertiser Big Island Bureau

The population explosion of mice on Maui appears to be waning and no new cases of murine typhus have been reported, health officials say.

Since March, there have been 19 cases of the bacterial disease, which is spread by fleas from infected rodents. Sixteen murine typhus cases have been reported on Maui and one each on Moloka'i, O'ahu and Kaua'i.

The most recent case involved a patient who came down with the flulike disease in the first week of August, Department of Health spokeswoman Janice Okubo said Friday.

Half of the Maui cases occurred in the Kihei and Wailea areas, where vector control crews have been setting up bait stations and spreading an oat mixture laced with zinc phosphate in vacant fields.

In the past week or so, there has been a "dramatic decrease" in the number of mice caught in traps used to monitor their numbers, said Herbert Matsubayashi, environmental health program chief for Maui.

"I think we're having some impact. The only troubling thing is that we've had rain on the 'Ulupalakua side (on the slopes above Wailea) and we don't know the dynamics of the mouse population."

The rains may regenerate the food supply and cause a resurgence of the critters, he said.

The Health Department is still waiting for approval from the Environmental Protection Agency for a special local-needs permit that would allow vector control crews to increase the amount of rodenticide that could be spread over the large pasture lands that surround South Maui, Matsu-bayashi said.

The Lahaina area also experienced an increase in mice, but crews have been limited by the U.S. Fish and Wildlife Service to using more labor-intensive bait stations to protect a population of endangered nene that inhabit the West Maui Mountains, he said.

Bruce Bowman of Bowman Termite & Pest Control said he has seen a lot less mouse activity while checking bait stations Upcountry and in Kihei. "It seems like it's dying down," he said. "Only in the last two weeks have I seen a decrease. They're still out there, but it's not as bad."

Maui's mouse problem first began drawing attention in May and June. Winter rains, after years of drought, helped the mice thrive in the island's vast open spaces above coastal communities. As the food supply began to wither under the summer heat, the creatures invaded populated areas.

Aside from causing a nuisance, the mice have damaged thousands of dollars worth of crops.

Bowman said that along with rodent-control measures, the prolonged dry, hot weather in Kihei may be forcing the mice to check their breeding habits because of the lack of food.