Review of larval food plant associations of the Agaristinae (Lepidoptera: Noctuidae) in Australia

The Australian Agaristinae comprises a small group of predominantly diurnal moths with aposematic larvae and adults that are assumed to be unpalatable to most predators. A critical review of the larval food plants of this subfamily based on published records in the literature, together with unpublished records, is presented. Of the 120 moth–plant species-level records, associations are documented for two-thirds of all species (34 out of 53, or 64%) and almost all genera (19 out of 21, or 90%) of Agaristinae. At the generic level, the overwhelming pattern is a high level of monophagy (12 genera on 1 plant family), followed by oligophagy (4 genera on 2 families); only three genera (Apina, Phalaenoides, Cruria) are polyphagous (>3 plant families). Despite high levels of specialisation, Australian Agaristinae, overall, feed on a set of 19 families of angiosperms in 16 orders and eight higher informal groups, most of which are not closely related. Lack of a well-resolved global phylogeny of Agaristinae precludes analyses of deep evolutionary patterns of host usage, but Vitaceae (Vitales) are the most widely exploited family (used by 12 moth species in 10 genera), followed by Dilleniaceae (Dilleniales) (used by 11 moth species in six genera). Available data indicate no evidence of phylogenetic conservatism in the Australian Agaristinae; rather, there appears to be a pattern of frequent host shifts and repeated colonisations to distantly related plants. The role of secondary plant compounds (e.g. sequestration of alkaloids and other metabolites) in chemical defence of Agaristinae requires further study, especially in the Vitaceae and Dilleniaceae.