Horse abortions and hairy caterpillars

horse abortions
Photo: Lynda Perkins

University of Queensland experts are set to help thoroughbred horse breeders combat a hairy caterpillar threat that causes horse abortions and is costing the Australian racing industry millions of dollars every year.

UQ School of Biological Sciences researcher Professor Meron Zalucki said bag-shelter moth (Ochrogaster lunifer) caterpillars were believed to be responsible for up to one third of abortions in thoroughbreds, causing equine amnionitis and fetal loss by inflaming the placental membrane.

“The caterpillars are covered with up to 2.5 million dangerous tiny hairs, and horses inadvertently ingest them or their nest remains,” he said.

Professor Zalucki is part of a team behind an insect management strategy to reduce the issue in the thoroughbred industry. The team have developed guidelines for studs and farmers to deal with the threat and are completing a risk assessment of horses’ exposure to the caterpillars. They have also developed educational resources including a website, a brochure and a poster with time lines for action.

Bag-shelter moth caterpillars are commonly known as processionary caterpillars because they walk nose-to-tail in lines when they leave their nests on gum or wattle trees.

Professor Zalucky advised stud owners to remove moth egg masses and caterpillar nests from tree trunks and branches and dispose of them safely.

“It’s important to be careful and to wear protective equipment when handling caterpillar material as the hairs can cause skin irritation and potentially get into eyes,” he said.

Professor Zalucki and his colleagues also plan to investigate the potential of biological controls using wasps that attack caterpillar eggs, methods of caterpillar hair dispersal, the possible involvement of other insects in equine amnionitis, and effects on other types of animals.


Please enter your comment!
Please enter your name here