North Queensland Naturalist

Abstract

Acraea terpiscore, the Tawny Coster butterfly was first observed on the east coast of Australia in Cairns on the 27th March, 2017. It arrived in large numbers as scattered southwesterly to southeasterly migration over Trinity Bay on hot prevailing winds drawn by Tropical Cyclone Debbie. Migration rates were concentrated on the first day of arrival and decreased as the butterflies dispersed or continued migrating. The expansion of A. terpiscore from near Darwin to Cairns yields a revised estimate of their rate of expansion at 334 km year-1.