Acoustic-defense
Guides
Amorpha juglandis
walnut sphinx
Amorpha juglandis, the walnut sphinx, is the sole species in the monotypic moth genus Amorpha (family Sphingidae). The species is notable for its caterpillar's unique defensive behavior: producing high-pitched whistles by expelling air through specialized abdominal spiracles. This acoustic defense has been experimentally shown to startle avian predators. Adults are nocturnal and active primarily during early night hours.
Cycnia
Cycnia is a genus of tiger moths in the family Erebidae, erected by Jacob Hübner in 1818. The genus contains several North American species, including the well-studied dogbane tiger moth (Cycnia tenera), which is known for its sophisticated anti-bat acoustic defenses. Species in this genus are typically associated with dogbane and milkweed plants, sequestering cardiac glycosides for chemical protection.
Euchaetes
tussock moths, milkweed tussock moths, milkweed tiger moths
Euchaetes is a genus of arctiine tussock moths in the family Erebidae, described by Thaddeus William Harris in 1841. The genus includes species commonly known as milkweed tussock moths or milkweed tiger moths, many of which are specialized feeders on milkweed plants (Asclepiadaceae). Caterpillars of well-known species such as E. egle sequester cardiac glycosides from their host plants, making them unpalatable to predators. Adults of some species have evolved ultrasonic acoustic defenses against bat predation, representing a notable example of acoustic aposematism.
Euchaetes egle
Milkweed Tussock Moth, Milkweed Tiger Moth
Euchaetes egle is a tiger moth in the family Erebidae, commonly known as the milkweed tussock moth or milkweed tiger moth. The species is notable for its gregarious caterpillars that feed on milkweeds and dogbane, sequestering cardiac glycosides from their host plants for chemical defense. Adults produce ultrasonic clicks from tymbal organs to warn bats of their unpalatability, representing a rare case of acoustic aposematism. The species occurs across eastern North America with one generation annually in northern regions and two or more in southern areas.
Yponomeuta
Small Ermine Moths
Yponomeuta is a large genus of small moths in the family Yponomeutidae, comprising 103 described species. Commonly known as Small Ermine Moths, members of this genus are notable for their distinctive defensive behavior: several species emit warning clicks during flight to signal their unpalatability to bat predators. Research on Yponomeuta cagnagella has demonstrated rapid evolutionary adaptation to urban environments, with populations exposed to long-term light pollution showing reduced attraction to artificial light sources compared to those from dark areas.