Wednesday, July 6, 2011

Bella Moth: Pretty Poison

Bella moth, Utetheisa ornatrix, truly is a beautiful moth, as "bella" suggests. We came across this one and,  the following  day, we saw it again (or another) in our vegetable garden. In my research to identify this moth, I learned that it is intricately intertwined with the the plant Crotalaria, commonly called rattlebox for the sounds the seeds make in the dried pods. There are plenty of rattlebox plants growing in the fields surrounding our garden, but this Bella moth was on a zinnia. It is not one of the larger flowers : that this is a rather small moth. Bella moths are diurnal --most moths are nocturnal---and  so are noticeable, especially with their lovely color and pattern.

Some damage has occurred to the wing. Some of the scales are missing, making it look dirty in the picture below. I found pictures online that show the wings spread---unnaturally, as the moth was dead. The hindwings are a solid darker coral, with black edges.

Rattlebox plants contain alkaloids which are highly toxic. Both male and female Bella larvae feed on the non-native rattlebox plants, including seeds, helping to keep this weed that is toxic to cattle at bay. This also makes Bellas toxic to predators in all three stages of their lives: egg, caterpillar and adult moth. A female will mate perhaps five times in the short three weeks that she lives as a moth. Not only does the male provide her with the necessary sperm, he also gives her more of the toxic alkaloids as well as nutrients, which allow her to lay many more eggs.  As a male approaches a female, he blows a little of his toxic gas her way and this helps her determine which male to choose. She  is looking for the most toxic. (I'm pretty sure there is not a human correlation here, unless it is in reverse!) 

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