Science and government leaders on have discredited a report by a Santa Cruz researcher that challenges the California's urgency in spraying pesticides to fight an invasive moth. The same leaders would not rule out the possibility that the federal government would take over spraying for the light brown apple moth if a court case stymies the state's efforts.

"This is an important, invasive pest with significant impact," said Osama El-Lissy, director of emergency management for the U.S. Department of Agriculture. "Our collective intention is to deal with [the moth], to prevent it from expanding to other states and to have the impact on agriculture, the environment and the ecosystem," he said.

El-Lissy was one of a handful of scientists and administrators explaining a report released Tuesday that criticizes the work of UC Santa Cruz Arboretum Director Daniel Harder and Watsonville grower Jeff Rosendale who, after traveling to New Zealand, concluded the moth is not the threat that county residents have been lead to believe. A group of federal, Californian, New Zealand and Australian scientists released their own report asserting:

• The Harder/Rosendale report fails to consider the natural resistance of New Zealand plants to the moth, which California plants do not have.

• The moth can travel up to 2 kilometers, not 100 meters as Harder and Rosendale reported.

• The issue is not only with the moth establishing itself in California, but with it moving to other states where it could cause serious damage.

"[The Harder/Rosendale] report offers a narrow perspective about options for managing [light brown apple moth] infestations," the state report said.

Harder said he stands by his science. County residents were in an uproar last year, when the state announced it would drop a synthetic pheromone, CheckMate LBAM-F, over urban areas to fight the light brown apple moth, an invasive pest from Australia. If left unchecked, state officials said the moth could wreak havoc on California agriculture. To stop it in time, they said, an environmental review of the decision to spray would not be possible. Planes took to the sky in November.

City and county leaders vehemently disagreed and sued the state. The case should be heard April 24 in Santa Cruz Superior Court. The situation prompted Harder and Rosendale to fly to New Zealand in January to see for themselves the damage the moth could do. They returned and wrote a report arguing that the state has overblown the threat of the moth, and said the bug could be controlled without aerial spraying by using techniques learned in New Zealand. In addition, they said, the moth is so established in California that the state's eradication efforts are futile…

While the moth has not landed outside the Golden State, it could move into most regions where the weather stays above freezing -- including the southern half of the U.S., and on the West Coast south of Washington, state panel members said. Should that happen, according to the state panel, Mexico, Canada and other countries could refuse all U.S.-grown produce. That would change the problem from a state to a federal one…