Asteraceae - an evaluation of hutchinsons beetle-daisy hypothesis

Abstract

There are cape Asteraceae species that have conspicuous dark markings on their ray florets. Such markings are usually interpreted as guides of various sorts. It is thus suggested that the dark raised marks on the ray florets of Gorteria diffusa thumb mimicked herbivorous beetles burrowing head down in the inflorescences. It is also noted that this species appeared to have few beetle visitors and to suffer less herbivory than other Asteraceae (such as an Arctotis sp.) growing nearby. The marks repel the beetles. However in this review of plant mimicry worldwide, it is considered an exceptionally intriguing example of Batesian mimicry. Despite the fact there still appears to be a dearth of information on the interaction between beetle-daisies and beetles, hence the purpose of this note is to extend the concept of beetle-daisies and to test Hutchinson’s hypothesis.