BELLA MOTHS: COLOURFUL, POISONOUS & PROMISCUOUS
Today’s offering is a creature I have never seen before on Abaco, or anywhere else for that matter. We saw it at the Neem Farm when we were looking for birds, butterflies and Spring flowers. I didn’t have moths in mind at all until I saw this one. For a start, moths are considered creatures of the night, so midday would not be an auspicious time for moth-hunting. As it turns out, the moth we found is, most unusually, active in day-time (‘diurnal’).
The BELLA MOTH Utetheisa ornatrix is also known as the ‘ornate moth’ or ‘rattlebox moth’ (after its favourite plant Crotalaria – me neither). The one we saw was pink, with bright pink showing on the wings in flight. However these moths come in other vivid colours ranging from pink to red or orange, and yellow to white. Their black wing markings have many patterns.
The bright coloration is, as in many species, nature’s way of saying ‘leave me alone’ and in particular, ‘I am very unpleasant to eat’. It is called APOSEMATISM. Quite simply, the larvae feed on plants that contain poisonous alkaloids – in particular the yellow rattlebox plant Crotalaria, rendering them, as adult moths, extremely unpalatable. Bella adults may cannibalise eggs, pupae or larvae to counter alkaloid deficiency.
BELLA MOTH SEX LIVES: “IT’S COMPLICATED”
- Sexual encounters are dictated by females, who compete with other females for males
- Females seeking to mate always outnumber available males
- A female bella will release powerful pheromones at dusk to lure males
- Related females uniquely engage in collective pheromone release
- This is termed “female pheromonal chorusing”
- Several males will give the female chemical ‘nuptial gifts’ of poison and sperm
- The female chooses the best of her suitors, and copulates with 4 or 5 of them
- The whole process of copulation may take up to 12 hours…
- In some way I don’t understand, she is then able to select her preferred sperm
- Humans: do not try any of this at home, in the office, in Maccy Ds or when driving
Credits: Header (on rattlebox blossom Crotalaria), Bob Peterson; 3 frankly rather feeble photos RH & Mrs RH; sharp photo by Charles J Sharp; open wings by Dumi