The bella moth, Utetheisa ornatrix, is one of our most beautiful moths. Unlike most moths, which are nocturnal, the bella moth is diurnal and flies readily when disturbed. Therefore, it is more commonly seen than nocturnal species.
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The adult bella moth is highly variable in coloration which has resulted in confusion regarding its taxonomy and the assignment of many names to the numerous color forms. Linnaeus originally described two species in the genus Phalaena -- ornatrix (more whitish or pale specimens) and bella (brightly colored specimens), and Hübner later moved them to the genus Utetheisa. Forbes lumped both forms under the species U. ornatrix. The Entomological Society of America's Common Names of Insects and Related Organisms publication uses the common name "bella moth," but uses the scientific nameUtetheisa bella (Linnaeus) instead of U. ornatrix (Linnaeus).
SEARCH THE ENTOMOLOGICAL SOCIETY'S DATA BASE via this link
The moth is plentiful this fall. Every time I water I inadvertently splash a number of these guys. They are small, with a wingspan of 3-4 cm (1.2-1.5 inches). They are plentiful because we have a bumper crop of Rattlebox (Crotalaria spp.). The Rattlebox and the bella moth's biology are intricately intertwined. The bella moth is one of the few insects that have evolved to use the Rattlebox as host due to the plants extreme toxicity (the plant is laced with pyrrolizidine alkaloids). The moths sequester these poisonous chemicals and thus become poisonous to predators.
The phenomenon of two organisms biologically interacting where each individual derives a fitness benefit (increased reproductive output), is referred to as "Mutualism," in Biology.
Read more about how the moths convert these poisons and use them to their advantage at the University of Florida's Institute of Food and Agricultural Sciences, Department of Entomology and Nematology.
Adult bellas live only about three weeks. They are considered beneficial insects as they ingest the poisonous seeds of the Rattlebox that would otherwise potentially poison cattle, livestock, or pets.
Read more about how Rattlebox came to Florida HERE.
The species we have cultivated is Crotalaria spectabilis Roth which is an invasive weed, native to Asia.
Below: My Rattlebox have grown to 9' (3 meters) tall and become spindly so I've been trimming them back for weeks. I'm saving some seed for next year's crop but not allowing them to spread. I found the first specimen on a walk in the woods some years back. On a recent drive in west Central Florida I noticed a lot of Rattlebox in the fields that have gone fallow.