2007 Annual Report
1a.Objectives (from AD-416)
1) To integrate weed and insect biological control to prvent the dispersal and spread of disease-vectoring thrips into agricultural environments..
2)Develop biologically based techniques to limit the spread of the invasive cactus moth, Cactoblastis cactorum.
1b.Approach (from AD-416)
1)Will combine systematic surveys of uncultivated and cultivated crop sites for reproductive hosts with manipulative field and lab experiments to test the ability of Frankliniella occidentalis to acquire Tomato Spotted Wilt Virus (TSWV) from weedy reproductive hosts and transmit it to crops. Because most thrips are transients in crop habitats, we will investigate the biotic-environmental factors underlying dispersal from weeds to crops and then determine how manipulation of certain weed reservoirs affect recruitment of viruliferous thrips into crops. Because a biological control agent, G. boliviana is available for tropical soda apple, this species is an excellent candidate to begin our examination of how herbivory from biological control agents affect other crop-herbivores and pest management issues. Success of this approach will provide impetus for future biological control programs for other weedy hosts of thrips and TSWV..
2)An inherent limitation of conservation biological control is overcoming the time lag between pest population increases and those of their natural enemies. Generalist predators may overcome this limitation by preying on nontarget prey. Orius insidiosus will serve as a model species for further investigation into relationships among non-crop plants, non-pest prey and predators of agricultural importance..
3)Will develop an effective monitoring system for adult C. cactorum by testing traps baited with the female sex pheromone and synthetic equivalents. A synthetic sex pheromone is currently under development by ARS..
4)Studies will be conducted to obtain information vital to modeling the spread and control of C. cactorum including: temperature influences on development, dispersal potential of C. cactorum and its potential North American Opuntia host-range. We will use mark-recapture trials to compare dispersal of sterile and fertile moths. Data will be incorporated into diffusion models using integro-difference equations to describe movement patterns. Data will also be used to construct life tables to estimate the effects of specific mortality factors such as SIT, biologicval control agents and host removal, on insect population dynamics.
Life table analysis for the cactus moth, Cactoblastis cactorum under different temperatures: implications for pest management
The cactus moth, Cactoblastis cactorum, is an invasive insect pest that was first reported in Florida in 1989 and has been moving westward in the southeastern United States towards Texas and Mexico where it would threaten native Opuntia cactus and the Mexican cactus industry. We studied development and reproduction of the cactus moth in the laboratory under different temperatures to determine its biological characteristics and provide information to develop strategies for its control. Development rate and female fecundity were temperature dependent, with optimum temperature of 30C. The most vulnerable lifestage appears to be the egg stage because it is exposed and has a long development time. Even after caterpillars enter the plant, specialized natural enemies may be effective in seeking and attacking larvae inside the cactus plant, as has been used in other biological control programs against similar pests. Research addresses NP-304, Crop Protection and Quarantine, and the Problem Statement associated with Action Plan Component III: Plant, Pest, and Natural Enemy Interactions, and Ecology; and Component IV: Postharvest, Pest Exclusion, and Quarantine Treatment.
Plant essential oils and kaolin for the control of tomato spotted wilt in tomato.
The thrips-vectored Tomato spotted wilt virus is the primary pest problem facing tomato production in the southern USA. Because insecticides do not effectively control primary infection by thrips immigrating into crop fields, scientists with the Center for Medical, Agricultural and Veterinary Entomology, the University of Florida, and the Università degli Studi della Basilicata, Potenza, Italy are investigating biologically-based, sustainable alternatives to manage thrips and tomato spotted wilt. Field trials demonstrated that tea tree oil combined with kaolin significantly reduce the incidence of tomato spotted wilt and increase yield. These findings indicate that naturally occurring products, such as plant essential oils and particle films, could be used successfully to reduce insecticide use on tomatoes without sacrificing yields. Research addresses NP-304, Crop Protection and Quarantine, and the Problem Statement associated with Action Plan Component III: Plant, Pest, and Natural Enemy Interactions, and Ecology and; Component V: Pest Control Technologies.
5.Significant Activities that Support Special Target Populations
Co-sponsor - Grape and Biological Control Field Day and Harvest Festival, Center for Viticulture and Center for Biological Control, Tallahassee, FL, 2006
|Number of invention disclosures submitted||1|
|Number of non-peer reviewed presentations and proceedings||17|
|Number of newspaper articles and other presentations for non-science audiences||18|
Heath, R.R., Teal, P.E., Epsky, N.D., Dueben, B.D., Hight, S.D., Bloem, S., Carpenter, J.E., Weissling, T.J., Kendra, P.E., Cibran, J. 2006. Pheromone-based attractant for males of cactoblastis cactorum (lepidoptera: pyralidae). Environmental Entomology. 35(6): 1469-1476.
Legaspi, J.C., Legaspi,Jr, B.C. 2007. Life table analysis for Cactoblastis cactorum immatures and female adults under five constant temperatures:Implications for pest management. Annals of the Entomological Society of America. 100(4):497-505.