Invasion of the potato hornworms!

Woman painting near Maui Tropical Plantation flees worms crossing the road

Hundreds of sweet potato hornworms crossed Honoapiilani Highway on Wednesday afternoon, headed in the direction of the Maui Tropical Plantation. Many were squashed but some crossed the road. SHARI RABBETT photo

It was the invasion of the sweet potato hornworm in Waikapu on Wednesday afternoon.

Shari Rabbett was intently painting near the sunflower patch at the Maui Tropical Plantation when she noticed something in her peripheral vision. At first, she thought they were centipedes and did the “two-step” when one attached to her sneaker.

She sent that sneaker flying in the air.

As she looked toward Honoapiilani Highway, Rabbett said there were hundreds of caterpillars, some brown, some lime green, coming from the old cane field makai of the Maui Tropical Plantation. The street looked like it was “curling,” she said with the creatures slithering across the highway like snakes.

Many were smashed by cars, but some made it to the other side of the road, she said.

Janelle Saneishi, spokeswoman for the state Department of Agriculture, showed a photo of the caterpillars to a department entomologist. The bug expert said the creatures were the caterpillar stage of the sweet potato hornworm.

The hornworm swarms every few years, the entomologist said. The insects are not toxic and were probably looking for food.

Saneishi pointed to a Wikipedia reference for Agrius cingulata, the sweet potato hornworm that turns into the pink-spotted hawkmoth, which has a wing span of 3§ to 4§ inches with a gray-brown body with pink bands.

The horned caterpillar feeds on the sweet potato and other plants. It is known as a sweet potato pest, the citation said.

The caterpillar and moth are found in Canada, Patagonia, the Falkland Islands, Galapagos Islands, Western Europe, West Africa and Cape Verde, the citation said.

Rabbett had gone to the sunflower patch to paint at about noon and conditions had become hot by 2 p.m. A half-hour later, she began seeing the mass of caterpillars slithering across the road. She escaped the area 20 minutes after the one crawled on her shoe.

“They were still coming,” Rabbett said as she left the scene.

She unexpectedly gave one a ride home as well.

“Where do caterpillars go when they hitchhike?” she wrote in an email. “Into art palette boxes and climb drapes and freak out the artists when painting is put on the easel.”

* Lee Imada can be reached at