Arctiinae
The Arctiinae (formerly called the family Arctiidae) are a large and diverse subfamily of moths with around 11,000 species found all over the world, including 6,000 neotropical species. This subfamily includes the groups commonly known as tiger moths (or tigers), which usually have bright colours, footmen, which are usually much drabber, lichen moths, and wasp moths. Many species have "hairy" caterpillars that are popularly known as woolly bears or woolly worms. The scientific name Arctiinae refers to this hairiness (Gk. αρκτος = a bear). Some species within the Arctiinae have the word "tussock"' in their common names because they have been misidentified as members of the Lymantriinae subfamily based on the characteristics of the larvae. Taxonomy The subfamily was previously classified as the family Arctiidae of the superfamily Noctuoidea and is a monophyletic group. Recent phylogenetic studies have shown that the group is most closely related to litter moths Herminiinae and the Old World Aganainae, which are subfamilies of the family Erebidae. The Arctiidae as a whole have been reclassified to represent this relationship. The family was lowered to subfamily status as the Arctiinae within the Erebidae. The subfamilies and tribes of Arctiidae were lowered to tribes and subtribes, respectively, of this new Arctiinae to preserve the internal structure of the group. Tribes (former subfamilies) Many genera are classified into these tribes, while others remain unclassified (incertae sedis). Arctiini Lithosiini Syntomini Description The most distinctive feature of the subfamily is a tymbal organ on the metathorax. This organ has membranes that are vibrated to produce ultrasonic sounds. They also have thoracic tympanal organs for hearing, a trait with a fairly broad distribution in the Lepidoptera, but the location and structure is distinctive to the subfamily. Other distinctive traits are particular setae (hairs) on the larvae, wing venation, and a pair of glands near the ovipositor. The sounds are used in mating and for defense against predators. Another good distinguishing character of the subfamily is presence of anal glands in females. Aposematism Many species retain distasteful or poisonous chemicals acquired from their host plants. Some species also have the ability to make their own defenses. Common defenses include cardiac glycosides (or cardenolides), pyrrolizidine alkaloids, pyrazines, and histamines. Larvae usually acquire these chemicals, and may retain them in the adult stage, but adults can acquire them, too, by regurgitating decomposing plants containing the compounds and sucking up the fluid. Adults can transfer the defenses to their eggs, and males sometimes transfer them to females to help with defense of the eggs. Larval "hairs" may be stinging in some species, due to histamines their caterpillars make. The insects advertise these defenses with aposematic bright coloration, unusual postures, odours, or in adults, ultrasonic vibrations. Some mimic moths that are poisonous or wasps that sting. The ultrasound signals help nocturnal predators to learn to avoid the moths, and for some species can jam bat echolocation. Behavior and life cycle Many of the caterpillars and adults are active during the daytime, but most species of this