Lyssa zampa, the tropical swallowtail moth or Laos brown butterfly, is a moth of the family Uraniidae. The species was first described by British entomologist Arthur Gardiner Butler in 1869.
The species is native to a wide range of tropical South-East Asia: Indonesia, Singapore, Malaysia, Thailand, and the Philippines. It is also recorded from Andaman Islands, southern China, the Himalayas, and sporadically in East Asia: Taiwan, Japan and South Korea. The forewing length is about 70mm and the wingspan reaches a maximum of 160mm.
It is most abundant from May to November depending on the location. The genus Lyssa is generally categorized as a nocturnal or crepuscular group, but this species has been found to be active both during the day and at night. This species is also known for its mass emergence and migration. Because of that ecology and the habit that they are often attracted by urban bright lights, this species can attract human attention.
The larvae feed on Endospermum and other members of the rubber tree family (Euphorbiaceae).