When caterpillars attack, nature and humans to blame

The recent caterpillar infestation in several sub-districts in Probolinggo, East Java, can be attributed to both environmental and human factors, an entomologist says.

Thousands of caterpillars have inundated Tegalsiwalan, Bantaran, Leces and Sumberasih in the past week. Residents were even forced to cut down mango trees that were ready for harvest.

According to Bandung Institute of Technology (ITB) entomologist Intan Ahmad, weather changes had created favorable conditions for caterpillars to breed. The favorable weather also increased the caterpillars’ chances of survival.

“The current warm yet damp weather is favorable for caterpillar breeding,” he said Thursday.

Intan said the abundance of food, including the availability of mangos, supported caterpillar survival.

“Caterpillars can feed on a variety of plants,” he said. “They feed on all sorts of green-colored plants.”

In addition to environmental conditions, he said humans also contributed to the presence of so many caterpillars by tipping the ecological balance. By practicing monoculture, residents eliminate trees and plants that support the natural predators of caterpillars.

“The caterpillars automatically have no rivals because there are no natural predators or parasites left that kill the caterpillars,” he told The Jakarta Post.

But, he said the caterpillars would die out naturally even without the help of insecticides once their food sources disappeared.

“They will probably start dying in less than a week without any food,” he said.