Synonyms and other taxonomic changes
Charidotella bicolor; formerly
Metriona bicolor; (
bicolor is considered a subspecies of
Charidotella sexpunctata in Borowiec's
World Catalog of the Cassidinae)
Explanation of Names
SEXPUNCTATA: "six-dotted" - when spots are present on the elytra, there are often six of them, three on each elytron
Identification
Overall golden-orange or golden-yellow color, with or without black spots on the elytra. Legs mostly yellow, body oval or almost circular-shaped, elytral margins transparent, elytra and pronotum highly reflective (shiny) in living specimens. See
Auburn site (listed under
Metriona bicolor) for detailed description.
Information
here suggests that adults change color when disturbed (Texas A&M U.), and
this page explains that the beetles can alternately develop/lose their black spots within a matter of hours (ashlandinternet.com).
Range
eastern US and southeastern Canada (plus California when the subspecies aurisplendens is included)
Food
Eats leaves of plants in the Convolvulaceae (Morning Glory family)
Remarks
Golden Tortoise Beetles found in the eastern US are either subspecies bicolor (which is the most widespread), or some other subspecies, depending on location: marylandica is found in Maryland, aurichalcea and pallida are found in the Carolinas, and floridana is found in Florida in the Miami, Orange Grove, and Tampa areas. No information could be found on the Internet describing how to distinguish these subspecies.
All individuals of Charidotella sexpunctata found in Canada are subspecies bicolor.
See Also
Black-legged Tortoise Beetle (Jonthonota nigripes) also has 3 black spots on each elytron and overall orange color but is larger (8-9 mm), has mostly black legs, a more oblong shape, a duller surface, and elytral margins are opaque or translucent - not transparent.
Print References
World Catalog of the Cassidinae by Lech Borowiec, University of Wroclaw, Poland, 1999.
Internet References
Bug of the Month - contributed by Hannah Nendick-Mason
taxonomic history plus synonyms, host plants, subspecies, and distribution (Cassidinae of the World)
preserved adult images (Cassidinae of the World)
adult images (Insects of Quebec)
distribution in Canada - PDF doc (Chrysomelidae, in: Checklist of the Beetles of Canada & Alaska)
common name reference for Sweet Potato Leaf Beetle (improvedbiosecurity.org)
