Dogbane tiger moth, Delicate cycnia
Cycnia tenera, the dogbane tiger moth or delicate cycnia, is a moth in the family Erebidae. It occurs throughout North America, from southern British Columbia to Nova Scotia southwards to Arizona and Florida. The species is distasteful and there is evidence that it emits aposematic ultrasound signals; these may also jam bat echolocation, as the functions are not mutually exclusive.
It is a common feeder on Apocynum cannabinum (dogbane, Indian hemp) which produces a milky latex containing cardenolides, toxic cardiac glycoside that defend against herbivores. It also feeds on milkweed species, Asclepias, at least in parts of its range, but is most commonly reported from dogbane. Its interactions with bats have been much studied, but are an area of dispute regarding whether the clicks emitted by adult moths are disruptive of bat echolocation, or merely aposematic warning signals. The two functions are not mutually exclusive, however, so it may not be possible to resolve the issue. The moth's coloration appears to be aposematic for insectivorous birds. Chemical signals do not prevent bats from attacking, but do cause bats to release C. tenera they have caught.
This moth has several generations per year through much of its range, so caterpillars may be found from June to November.
Eggs are laid in clutches of 50–100. Larvae are reported to feed in aggregations of five to seven, at least in the early instars. Caterpillars are covered all over in soft grey to whitish hairs. Larvae feed at night.
The cocoon is grayish and covered in hairs from the caterpillar's body.
Adults have white wings with a buttery yellow margin along the front of the forewing; the legs are black. The underside of the forewing may have a dusting of black. The body is yellow with a row of black spots. The wingspan is 30–40 millimetres (1.2–1.6 in).
