Tarweed
Guides
Heliothodes
Heliothodes is a small genus of owlet moths in the family Noctuidae, subfamily Heliothinae, containing two described species: H. diminutivus and H. joaquin. The genus was established by Hampson in 1908. At least one species, Heliothodes diminutiva, is a specialist herbivore of tarweed (Madia elegans) in California, where its caterpillars feed on developing flower buds and can completely sterilize host plants.
Heliothodes diminutiva
Small Heliothodes Moth
Heliothodes diminutiva is a small owlet moth in the family Noctuidae, native to western North America. The species is a specialist herbivore whose larvae feed on the reproductive structures of tarweed (Madia elegans), a sticky annual plant in the Asteraceae family. Adult females lay eggs on developing flower buds, and emerging caterpillars can consume all flowers and buds, potentially sterilizing host plants. This species has been extensively studied in the context of plant indirect defense mechanisms, where trapped insect carrion on sticky plants attracts predators that reduce herbivory.