A. horridus is found throughout much of the North Island, as well as some parts of the South Island. It is present in coastal areas from sea level to at least 900 m a.s.l. The species is absent in the central South Island and in high-altitude areas. It has also been found on a number of offshore islands, including the Chatham Islands. On the Chatham Islands only females occur and this population was once considered a different species (A. schauinslandi). It can be found in gardens on ramarama (Lophomyrtus bullata) and in the wild on native and introduced Rubus species (Rosaceae) and climbing rata (Metrosideros perforata). Because of its wide distribution, range of host plants and the various habitats it is found in, A. horridus is considered an ecological generalist.
