Macaria fusca (Thunberg, 1792) is a small geometer moth species that inhabits mountain heathland just above the timberline and occasionally warm forest openings in the mountains. Existing literature describes the species overwintering as a half-grown larva. However, in our observations, we detected an alternative overwintering strategy of M. fusca as a half-developed egg, contrary to the claims in the literature. Additionally, we briefly describe the rearing methods of the species and document what appears to be the first known outbreak of the species.