Biocontrol Science and Technology (2010) 20, 791-807

William A. Overholt, Rodrigo Diaz, Larry Markle and J.C. Medal (2010)
The effect of Gratiana boliviana (Coleoptera: Chrysomelidae) herbivory on growth and population density of tropical soda apple (Solanum viarum) in Florida
Biocontrol Science and Technology 20 (8), 791-807
Abstract: The effect of herbivory by Gratiana boliviana Spaeth (Coleoptera: Chrysomelidae) on the invasive, tropical soda apple (TSA) (Solanum viarum Dunal, Solanaceae), was investigated using exclusion methods and by monitoring the density of G. boliviana and the weed at four locations over a period of 40 months. TSA plants protected by insecticide were taller, wider, and had greater canopy cover that unprotected plants, and plants in closed cages were taller and wider than those in open cages. Survival of plants was higher in plots protected with insecticide than in unprotected plots in both years of a 2-year study. In the population dynamics study, the initial density of TSA was 4-5 times higher at one of the locations than at the other three sites, but within 3 years, TSA density at the high density site had declined by 90%. At the three sites which initially had a low abundance of TSA, density remained low throughout the study. The intrinsic rate of increase of G. boliviana varied between -3.9 and 4.5, but over the 3-year study, was not different from zero, indicating a stable population. The intrinsic rate of increase was lower than zero for the period from October to January, and greater than zero during the January to April period. In the periods from April to July and July to October, the rate of increase was not different from zero. The implications of these results for biological control of TSA in Florida are discussed.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): William A. Overholt, Rodrigo Diaz, Julio C. Medal

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution
population dynamics/epizootiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Solanum torvum (weed)		U.S.A. (SE)
Gratiana boliviana (weed bioagent)	Solanum torvum (weed)		U.S.A. (SE)