Gratiana boliviana | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Coleoptera |
Family: | Chrysomelidae |
Genus: | Gratiana |
Species: | G. boliviana |
Binomial name | |
Gratiana boliviana Spaeth, 1926 |
Gratiana boliviana is a species of beetle in the leaf beetle family, Chrysomelidae. Its common name is tropical soda apple leaf beetle. It is native to South America, where its distribution includes Argentina, Brazil, and Paraguay. It specializes on tropical soda apple (Solanum viarum), an invasive plant species. It has been released as an agent of biological pest control against the weedy plant in Florida and other parts of the United States.
The adult beetle is about 6 millimetres (0.24 in) long and 4 to 5 millimetres (0.16 to 0.20 in) wide. The young adult is green in color and turns yellow as it ages. It is pale brown during its overwintering stage, when it enters diapause. The ventral abdomen is somewhat transparent, and during its reproductive season the internal sex organs become visible: white oviducts in the female and orange testes in the male.
The larva is light green and covered in spines. Older larvae usually carry fecal shields. The pupa is flattened and pale green in color. It rests attached to the underside of a leaf.
In Florida, diapause occurs in December through March, during which time the adult is dormant and hidden in leaf litter. Starting in March or April, the adults come out to feed and mate. Seven to eight generations occur during the year. The female lays single eggs on the leaves of the tropical soda apple plant. A female can produce about 300 eggs. Each egg is between 1 and 2 millimetres (0.039 and 0.079 in) long including its wide, transparent, papery casing. The larva emerges in 5 to 6 days, feeds voraciously, progresses through five instars, and becomes a pupa after 16 to 18 days. Pupation lasts about a week. The female beetle lives 3 to 4 months.