You are likely thinking of the Black Witch moth (Ascalapha odorata). It is a massive, dark brown-to-black moth with a wingspan of up to 6–7 inches. Because of its erratic, bat-like flight and large size, it frequently startles people when it flies into porches or garages. [1, 2, 3, 4, 5, 6]

Here is everything you need to know about this iconic Yucatan visitor:

Appearance & Behavior

• Size & Color: Females are easily recognized by a striking, distinct white (or pinkish-white) band that crosses their wings, while males are uniformly dark and lack this band. [1, 2]
• Habits: They are strictly nocturnal. During the day, you will often find them resting perfectly still on the walls or ceilings of buildings, silently blending in. [1, 2, 3, 4]
• Diet: Adults are entirely harmless and feed on overripe, fermenting tropical fruit (like bananas) and tree sap, not on fabric or clothing. [1, 2, 3]

Cultural Lore in the Yucatan

This moth is deeply rooted in local history and folklore. [1]

• In Maya, it is called X-mahan-nah, which translates roughly to “house-borrower” or “may I borrow your house” because of its habit of sheltering under eaves. [1, 2]
• In broader Mexican and Central American folklore, it is famously dubbed the “mariposa de la muerte”(butterfly of death). Superstition holds that if one flies into a home where someone is ill, it is an omen of death. [1, 2, 3, 4]
• Conversely, in the Bahamas and Hawaii, this moth is known as a symbol of good luck or a sign that money is coming. [1, 2]

For tips on how to safely attract, observe, and photograph large tropical moths like the Black Witch in your garden: