Friday, 20 August 2010

Witches of the tropical night sky

At certain times of the year, normally around December and January, it´s not uncommon to see "bats" fluttering through the night, and circling street lights. It´s only when they enter your apartment that you realise that they are huge moths, "bruxas". Bruxa means "witch" and this matches the English name, the "Black witch moth" and in deed the size of the moths has impressed many peoples, so that in French it is "La Sorcière Noire" (the Black Witch) and in Spanish, "Mariposa de la Muerte" (the Moth of Death!). The Mayans, with rather more humour, call them "Mah-Ha-Na", or "May I borrow your house", an allusion to their habit of entering houses, and the way they make their presence felt when they are there!

In fact, although Ascalapha odorata is large (up to 16cm) it is completely harmless. Indeed they can actually be eaten, well the larvae. They are especially a delicacy in Mexico and feature prominently in a book by Professor Julietta Ramos Elorduy on edible insects, which includes a recipe for "Black witch fondue". According to another source they have the taste of herring.

Ascalapha are found from the southern USA to Rio Grande do Sol in Brazil, and they are, not unnaturally, strong fliers, migrating through their range. The adult males and females can be distinguished by a pale stripe across the wings of the females and feed on fruit, though unlike some moths they cannot penetrate the skin and have to feed on rotten or damaged fruits. The huge larvae (up to 7cm) feed on leaves, and can be a pest of figs and mesquite.

It is not just humans who can eat then, adults make a tasty meal for bats too. Ascalapha is not without defences though. Bats hunt by echo location, or radar, and Ascalapha has the ability to tune it´s ears to the particular frequency of local bats and take evasive action when they are close.
So this is the Black Witch Moth, not dangerous, but magic in it's own way.


Anonymous said...

Very interesting! And also funny: "may I borrow your house" is really funny!!!!

Cesar Crash said...

The first beauty is a male Thysania zenobia.