Acrodipsas illidgei is an endangered butterfly inhabiting mangrove forests in southeastern Queensland, Australia. Concern over the effects of mosquito control activities prompted a broad-scale survey for the species at Coomera Island, in southeastern Queensland. The butterfly was recorded on the edge of an old-growth mangrove forest in close proximity to mosquito control runnels. Other forms of mosquito control at Coomera Island are unlikely to impact on the species because of the mode of action of larvicides used and the fact larvae occur within ant colonies formed in hollow stems and branches of mangrove trees. Further studies are required to more fully understand the relationships between mosquito control activities and the population dynamics of endangered species such as A. illidgei.