Gratiana

Spaeth, 1913

Species Guides

2

Gratiana is a of tortoise beetles ( Chrysomelidae, Cassidinae) comprising approximately seven described . Members of this genus are characterized by the flattened, shield-like body form typical of tortoise beetles, with capable of clamping tightly against leaf surfaces as a defensive . The genus is best known for Gratiana boliviana, which has been employed as a agent against the weed tropical soda apple (Solanum viarum) in the southeastern United States.

Gratiana pallidula by (c) Nate Sabo, some rights reserved (CC BY), uploaded by Nate Sabo. Used under a CC-BY license.Gratiana boliviana by Peggy Greb, USDA Agricultural Research Service, Bugwood.org. Used under a CC BY 3.0 license.Gratiana pallidula, U, Face2, Patuxent WRC, MD 2013-07-09-12.40.04 ZS PMax (9247847859) by Sam Droege from Beltsville, USA. Used under a Public domain license.

Pronunciation

How to pronounce Gratiana: //ɡræˈtiːænə//

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Identification

Tortoise beetles in this possess the characteristic cassidine body plan: broadly oval, strongly convex dorsally, and capable of pressing the body margins flat against the substrate. The pronotum and together form a continuous shield-like covering. Specific identification to level requires examination of body proportions, punctation patterns, and coloration. Gratiana pallidula is pale in coloration, while G. boliviana exhibits more typical tortoise beetle patterning.

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Habitat

Associated with Solanum plants; G. boliviana occurs in pastures and conservation areas where tropical soda apple grows. Native South American occupy corresponding in their region of origin.

Distribution

Native to South America; G. boliviana introduced and established in Florida, USA as part of programs. Other occur in the Neotropics.

Diet

Herbivorous; feeders on Solanum . Gratiana boliviana feeds exclusively on tropical soda apple (Solanum viarum).

Host Associations

  • Solanum viarum - primary tropical soda apple; for G. boliviana
  • Solanum elaeagnifolium - silverleaf nightshade; for G. pallidula

Life Cycle

Temperature-dependent development; has been documented in G. boliviana. Detailed information for most is limited.

Behavior

exhibit a characteristic defensive of clamping down flat against the leaf surface, using their flattened body margins to present a difficult surface for to grasp.

Ecological Role

Herbivores on Solanum plants; G. boliviana serves as a agent that reduces of tropical soda apple, mitigating impacts on cattle grazing, native plant , and wildlife movement.

Human Relevance

Gratiana boliviana has been mass-reared and released across Florida (over 250,000 individuals from 2003–2011) for of tropical soda apple, an weed in pastures and conservation areas.

Similar Taxa

  • CassidaBoth are tortoise beetle in Cassidinae with similar body form; Gratiana distinguished by specific associations and subtle morphological differences
  • CharidotellaAnother cassidine with similar shield-like body form; -level examination required for separation

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