September Treasure: Black Witch Moth
Tara A. Spears
The month of September vibrates with patriotism and in the natural world there is much to celebrate, too. While I don’t like the wasp swarms I do enjoy the nocturnal moths, Ascalapha odorata, commonly known as the black witch moth, is a large bat-shaped, dark-colored moth, ranging from Brazil to the southern United States. It is the largest noctuid in North America. In the folklore of many Central American and Mexican cultures, this moth is associated with death or misfortune.
Female moths can attain a wingspan of 17 cm. The dorsal surfaces of their wings are mottled brown with hints of iridescent purple and pink, and, in females, crossed by a white bar. The diagnostic marking is a small spot on each forewing shaped like a number nine or a comma. This spot is often green with orange highlights. Males are somewhat smaller, reaching 12 cm in width, darker in color and lacking the white bar crossing the wings. The larva is a large caterpillar up to 7 cm in length with intricate patterns of black and greenish-brown spots and stripes. 
The black witch moth, referred to as ‘polilla negra Ascalapha odorata locally, lives throughout Central America and Mexico, from Brazil to the southern United States. Adults feed on overripe rainforest fruit, especially bananas, and larvae consume the leaves of plants. Most of its host plants are legumes and specific tree species therefore this moth can be an agricultural pest. In my Guayabitos garden, they love the lime tree.
I always appreciate the myths concerning natural phenomenon: it illustrates so much about a culture. I uncovered some interesting beliefs concerning the Black Witch Moth in the book Natural & Cultural History author written by Mike Quinn: “In Spanish, the black witch moth is known as “mariposa de la muerte” or the mourning moth or the sorrow moth.”
Perhaps due to its nocturnal habit and large size, in Mexico the Black Witch Moth is a source of fear and worry. For example, if it flies into a house when someone is ill it is feared to be a sign of certain death. From the pre-Hispanic era until the present time, moths have been associated with death and the number four. In some parts of Mexico, people joke that if one flies over someone’s head, that person will lose his hair.
But other cultures have a more positive spin to Black Witch moth siting. In Hawaii, the black witch moth mythology, though associated with death, has a happier note in that if a loved one has just died, the moth is an embodiment of the person’s soul returning to say goodbye. In the Bahamas, where they are locally known as money moths or moneybats, the legend is that if they land on you, you will come into money, and similarly, in South Texas, if a black witch moth lands above your door and stays there for a while you will supposedly win the lottery!
The most famous example of BWM symbolism in popular use is as a tattoo or in the film, Silence of the Lambs. Even if folklore doesn’t seem mysterious or appeal to your darker side, seeing the exotic Black Witch moth is part the Mexican experience.
The book by Charles L. Hogue, Latin American Insects and Entomology, is the source of much of this information.