With its ornate temples, lush rice fields and lively beach resorts, the island of Bali is a tourist mecca. But this year, some uninvited visitors showed up – millions of stinging caterpillars.

"They call it caterpillar rain," said Aunu Rauf, a professor at Bogor Agricultural University in central Java. There, people began carrying umbrellas to keep the black, white and orange larvae off their hair and away from their skin.

Rauf said insect infestations are becoming increasingly common, with growing global trade allowing pests to travel from one side of the world to the other. In Bali, the insects devoured mango groves and drove housewives to distraction by invading homes.

The fight against unwanted insect pests is especially pitched in the tropics, where warmth and humidity allow insects and fungi to thrive, competing with farmers for edible crops.

Heavy use of chemicals

Rauf and a colleague travel the steep, rutted roads in the hills of Bali – past orchards, vegetable patches and smiling schoolgirls in their white headscarves. In Chuputri, farmers have long relied on chemical sprays to keep bugs at bay.

Yayi Kusumah, an insect virologist, said one farmer sprays pesticide every week. "Sometimes twice a week," he stated, adding that this is not good for the environment or the farmer.

"They use their hands to mix the pesticide – and we know that's not very healthy," Kusumah said.

Parents worry about the health of children living on farms. Skin irritation is a common problem, and local mother Eriska blamed pesticides for cases of cancer and birth defects.

But Kusumah said farmers and government regulators see little alternative, since they have 240 million mouths to feed.

Quest for non-toxic alternatives

The U.S. Agency for International Development is sponsoring the Integrated Pest Management program, which includes three sites in the rugged hills of Indonesia.

With help from the agency, Rauf and Kusumah have been telling Indonesian farmers about less conventional ways to protect crops.

For example, by mashing up a combination of garlic, shallots, hot peppers and citrus skin into a paste. By adding water, these farmers make a natural spray for their vegetables.

It's good for the environment, and also translates into higher returns. On the market, farmers can demand more than twice the price for organic over conventionally grown produce. What's more, by eliminating pesticide use, farmers cut costs by 20 to 30 percent.

Funded with a $15 million grant from Washington, the effort to spread green pest control technologies is set to continue for at least four more years.

Promoting natural pest control

Pak Jayamudin, who began using the organic spray last year, is hooked. He proudly displays a large bunch of carrots – which he swears are sweeter and crispier than chemically grown carrots.

At the community radio station, hosts make frequent announcements about training programs for farmers. Delegations have come from as far away as Thailand and Singapore to see how the Integrated Pest Management program works.

They learn about parasites and viruses that can be used to attack specific insects – natural agents that can kill pests in fields.

In the hills of Bali, Rauf and Kusumah have introduced a friendly fungus that eats disease-causing pathogens in the soil.

Pak Ujang Dayat has been farming for more than 20 years, and he's never seen anything like this culturable fungus, which is in the Trichoderma genus.

Dayat grows the black fungus in a bag of corn kernels, then combines this with compost and spreads the Trichoderma mix across his fields. With this, he has warded off a damaging root disease.

Treating seeds with Trichoderma seems to provide early protection for crops, and studies show such seeds produce stronger, longer roots that also make them more drought-resistant.

The Trichoderma is so good that farmer Dayat and his neighbors produce a surplus of crops, and sell the excess to a company that distributes it nationwide.

Of course, none of these approaches provides full protection to every leaf – but that's okay. Rauf says the occasional hole in a leaf actually increases its market value.

"It proves that they did not use the insecticide."

Author: Sandy Hausman/ sad
Editor: Andrea Rönsberg