Releases, distribution and abundance of Gratiana boliviana (Coleoptera: Chrysomelidae), a biological control agent of tropical soda apple (Solanum viarum, Solanaceae) in Florida (original) (raw)
Related papers
Biocontrol Science and Technology, 2010
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.
Environmental Entomology, 2011
The leaf feeding beetle Gratiana boliviana Spaeth has been released since 2003 in the southeastern United States for biological control of tropical soda apple, Solanum viarum Dunal. In Florida, G. boliviana can be found on tropical soda apple growing in open pastures as well as in shady wooded areas. The objectives of this study were to determine the effect of light intensity on the performance of tropical soda apple and G. boliviana under greenhouse conditions, and to determine the abundance and mortality of G. boliviana in open and shaded habitats. Leaves growing in the shade were less tough, had higher water and nitrogen content, lower soluble sugars, and less dense and smaller glandular trichomes compared with leaves growing in the open. Plants grew slightly taller and wider under shaded conditions but total biomass was signiÞcantly reduced compared with plants grown in the open. In the greenhouse, G. boliviana had higher immature survival, greater folivory, larger adult size, and higher fecundity when reared on shaded plants compared with open plants. Sampling of Þeld populations revealed that the overall abundance of G. boliviana was lower but leaf feeding damage was higher in shaded habitats compared with the open habitats. The percentage of eggs surviving to adult was greater in shaded compared with open habitats. The abundance of predators was higher in the open pasture and was positively correlated with the abundance of G. boliviana. These results indicate that not only plant quality but also habitat structure are important to the performance of weed biological control agents.
Annals of the Entomological Society of America, 2011
The South American leaf-feeding beetle Gratiana boliviana Spaeth (Coleoptera: Chrysomelidae) has been released since 2003 in the southeastern United States to control the invasive weed tropical soda apple, Solanum viarum Dunal (Solanaceae). Successful establishment of a biological control agent in temperate and subtropical regions depends on several life-history adaptations, including winter diapause. The timing of diapause allows the syncronization of insect herbivores with the phenology of plants, and field observations in Florida suggested that G. boliviana overwinters as an adult in diapause. The objectives of this study were to describe the diapause of G. boliviana and determine the effect of temperature and photoperiod on diapause induction. Compared with nondiapause adults, diapausing adults were yellow rather than green, had hypertrophied fat bodies, contained little food in the digestive tract, showed negligible ovarian development, and minimal movement of the hind wings wh...
Florida Entomologist, 2010
Multiple-choice and no-choice tests were conducted at the Department of Agriculture, Division of Plant Industry Quarantine facility in Gainesville, FL to determine the specificity of the Brazilian leaf-beetle Gratiana graminea Klug, a candidate for biological control of Solanum viarum, tropical soda apple. One hundred fifteen plant species in 32 families were included in the feeding-oviposition multiple-choice tests including the target weed and the 5 major cultivated Solanaceae Capsicum annuum L., Lycopersicon sculentum Mill., Nicotiana tabacum L., Solanum melongena L., and Solanum tuberosum L. Eight to 12 plant species, including always the main target weed, growing in 1-gallon pots were simultaneously exposed to 20 G. graminea adults (10 males and 10 females that most of the time had recently emerged from pupae) in an aluminum cage (60 × 60 × 60 cm). At the beginning of each test the insects were placed at the bottom center of each cage to allow them to orient by themselves to the tested plants. Plant species in each test were replicated 3-4 times (one replication of tested plants in each separate cage). Plants tested were exposed to G. graminea adults from 3-6 weeks. Observation of oviposition and feeding were made during almost all the weekdays. No-choice host specificity tests were conducted with G. graminea adults on potted plants in cages made of clear-plastic cylinders and with G. graminea larvae placed on cluster of leaves of each individual plant tested. Ten G. graminea adults were exposed to 29 plant species individually tested during 3 to 5 weeks, and 10 neonate larvae were exposed to 31 plant species. Plant species in each test were replicated 3-4 times. Results indicated that G. graminea fed and developed only on the target weed. The tests indicated that a host range expansion of G. graminea to any of the major cultivated Solanaceae species is highly unlikely. A petition for field release in Florida was submitted to the Technical Advisory Group for Biological Control Agents of Weeds (TAG) in Sep 2008.
Biocontrol Science and Technology, 2008
The leaf beetle Gratiana boliviana Spaeth (Coleoptera: Chrysomelidae) was introduced from South America into the southeastern United States in 2003 as a classical biological control agent of tropical soda apple, Solanum viarum Dunal (Solanaceae). Temperature-dependent development and survival studies revealed that development was completed at temperatures >16°C and ≤34°C. The number of degree-days required to complete one generation was 341 and the estimated lower developmental threshold was 13.37°C. Using nonlinear regression, the upper lethal threshold was estimated to be 34–35°C. Cold tolerance studies revealed that the lethal time for 90% of adults (LT90) was 12.6 days at 5°C and 8.68 days at 0°C. Based on the developmental and cold tolerance data, a map predicting the areas of establishment and number of generations per year was generated, which suggests that the northern extent of the G. boliviana range in the USA will be near 32–33° north latitude. Fewer generations per year in more northern areas of the southeastern USA may decrease the effectiveness of this biological control agent.
Florida Entomologist, 2011
Multiple-choice and no-choice tests were conducted at the Florida Department of Agriculture quarantine facility to determine the host specificity of the South American flower bud weevil, Anthonomus tenebrosus Boheman, intended for biological control of the exotic weed tropical soda apple (TSA), Solanum viarum Dunal in Florida, USA. Ninety-one plant species in 21 families were included in multiple-choice feeding and oviposition experiments, including the target weed and the 6 major cultivated Solanaceae: bell pepper ( Capsicum annuum L.), chili pepper ( C. frutescens L.), tomato ( Lycopersicon esculentum Mill.), tobacco ( Nicotiana tabacum L.), eggplant ( Solanum melongena L.), and potato ( Solanum tuberosum L.). Plant bouquets with flower-buds of 8 to 10 randomly selected plant species, always including TSA ( S. viarum ) were exposed to 10-20 A. tenebrosus adults for 1 to 2 weeks. Oviposition and feeding were observed twice a week. No-choice host-specificity tests were also conducted with A. tenebrosus adults using potted flowering plants. Ten adults were exposed to 29 plant species individually tested for 1 to 2 weeks. Plant species in each test were replicated 3 or 4 times. All tests showed that A. tenebrosus fed and laid eggs only on the target weed. No eggs were deposited on any of the other of the 91 plant species tested. Host-specificity tests indicated that a host range expansion of A. tenebrosus to include any of the crops, and native Solanaceae, and non-solanaceous plants tested is highly unlikely. A petition for field release in the USA Pruebas de ovoposición y alimentación (con y sin elección), se realizaron para evaluar la especificidad del picudo del botón floral, de origen suramericano, Anthonomus tenebrosus Boheman, como agente potencial para control biológico de bola de gato, Solanum viarum Dunal en los Estados Unidos. Las pruebas se efectuaron en la cuarentena del Departamento de Agricultura de la Florida. Noventa y una especies de plantas, en 21 familias, fueron incluidas en las pruebas de especificidad de múltiples elección, incluyendo la maleza objetivo y las seis plantas cultivadas pertenecientes a la familia Solanaceae más importantes: chile dulce ( Capsicum annuum L.), chile ( Capsicum frutescens L.), tomate ( Lycopersicon esculentum Mill.), tabaco ( Nicotiana tabacum L.), berenjena ( Solanum melongena L.), y papa ( Solanum tuberosum L.). En cada prueba se utilizaron racimos florales de ocho a diez plantas escogidas al azar incluyendo siempre la planta objetivo las cuales fueron expuestas a 10-20 adultos de A. tenebrosus por una a dos semanas. Registros de alimentación y ovoposición fueron realizados dos veces por semana. Pruebas de alimentación/ovoposición sin elección fueron también realizadas usando plantas en floración. Diez adultos fueron expuestos a 29 especies de plantas en forma individual por una a dos semanas. Cada prueba tuvo tres o cuatro repeticiones. Las pruebas mostraron que A. tenebrosus se alimentó y colocó posturas solo en bola de gato. Ninguna postura fué depositada en las otras 90 especies de plantas evaluadas. Las pruebas indicaron que la posibilidad de A. tenebrosus de llegar a ser una plaga de las Solanaceae cultivadas es muy remota. La solicitud al comité TAG para liberar el picudo en los Estados Unidos fue presentada en octubre 2007.