Source: UNIVERSITY OF GEORGIA submitted to
INTEGRATED PEST MANAGEMENT OF INSECT PESTS OF FLUE-CURED TOBACCO
Sponsoring Institution
State Agricultural Experiment Station
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0198236
Grant No.
(N/A)
Project No.
GEO00243
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Oct 1, 2003
Project End Date
Sep 30, 2009
Grant Year
(N/A)
Project Director
McPherson, R. M.
Recipient Organization
UNIVERSITY OF GEORGIA
200 D.W. BROOKS DR
ATHENS,GA 30602-5016
Performing Department
ENTOMOLOGY
Non Technical Summary
Insect pests are an annual economic threat to Georgia's flue-cured tobacco crop from soon after seedling emergence until the crop is harvested and cured. This tobacco project will integrate cultural, chemical and biological control of insect pests into a pest management program that will reduce pest-induced crop injury.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
21119101130100%
Goals / Objectives
To study the biology and population dynamics of insect pests and their natural enemies in flue-cured tobacco produced under standard greenhouse, transplant water, and foliar insecticide treatment regimes. To determine the impact of tobacco production practices and thrips management tactics on the abundance of thrips and the incidence of TSWV. To evaluate experimental insect control strategies for efficacy on target species and their impact on non-target organisms, and monitor for insecticide resistance. To evaluate tobacco cultivars, breeding lines, and plant introductions for potential insect resistance characters.
Project Methods
Use replicated large field plots to monitor the seasonal abundance (weekly sampling) of arthropod pest and beneficial species in flue-cured tobacco and correlate the incidence of insect populations with crop phenology, cultural practices and pesticide usage. Examine the effectiveness of selected tray drench, transplant water and foliar insecticide treatments on the abundance of thrips pests and the incidence of tomato spotted wilt virus. Evaluate new pesticides for their effacacy on controlling tobacco insect pests. Screen tobacco genotypes for resistance to naturally occurring infestations of hornworms, budworms, thrips and aphids in replicated small plot trials.

Progress 10/01/03 to 09/30/09

Outputs
OUTPUTS: Tobacco insect pests cost Georgia producers over 2.5 million dollars in costs of control and damage in 2009. In addition, another 2 million dollars was reported in losses due to tomato spotted wilt virus (TSWV), a disease that is vectored by tiny insect pests called thrips. Seventeen different weed hosts in the tobacco farmscape had a total of 1209 adult thrips collected from them during January through mid-May 2009. Frankliniella fusca, the tobacco thrips, a reported vector of TSWV, was collected from 14 of these plants species. Another vector, F. occidentalis, was collected from blooms from 7 of the host plants. Over 85% of the thrips collected on tobacco foliage were F. fusca. Less than 1% of the thrips collected on tobacco blooms were F. occidentalis. Most flower thrips were F. tritici, a non-vector thrips species. Most thrips movement within the tobacco field occurred between 0900h and 1600h. Tray drench applications on Admire and Durivo applied 2 days prior to transplanting, reduced the seasonal incident of TSWV around 35%. Tracer, Coragen, Steward, Lannate, Denim, Brigade, Orthene, Brigadier, Durivo, HGW86, Rimon, Voliam and Belt were effective in controlling tobacco hornworms, and budworms. Orthene, Lannate, Brigadier and Voliam Flexi were effective in controlling tobacco aphids for up to 14 days after the treatments were applied. Selected transplant water and foliar sprays of insecticides reduced the incidence of tobacco splitworms and the number of tunnels in tobacco leaves. Coragen, Brigade, Warrior, Rimon, HGW86, Belt, Durivo, and Voliam Flexi all provided season-long suppression of splitworm damage. Tobacco splitworm pheromone traps were examined for their effectiveness in predicting pest outbreaks and crop damage. Higher nitrogen fertility rates (90 lbs.N./acre) did increase the incidence of TSWV compared to plots with no nitrogen applied. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
This research project has demonstrated that preplant applications of the insecticides imidacloprid and thiamethoxam can significantly reduce the indicence of tomato spotted wilt virus (TSWV) in tobacco, and potentially save growers millions of dollars annually from this disease. This project has also documented that the tobacco thrips is the predominate vector of TSWV in the Georgia tobacco farmscape. Numerous alternate plant hosts harbor thrips vectors and TSWV innoculum. Several pest management practices have been identified to help manage TSWV. This research project examined insecticides and insecticide combinations annually to provide the most up-to-date, effective, economical, and environmentally sound control options for Georgia producers. This project also has documented the widespread development of tobacco budworm resistance to pyrethroid insecticides. Thus, growers will be encouraged to use alternative insecticides when budworm controls are required, to insure effective control of this key pest. Effective chemical control options are also now available for season-long suppression of tobacco splitworms and pheromone traps can be used to predict when splitworm infestations occur in tobacco and when to properly time the insecticide applications for effective control.

Publications

  • Riley, D., R. McPherson, L. Wells, and S. Brown. 2009. Management of thrips vectors of TSWV. University of Georgia Coll. Agric. Environ. Sci. Bull. 1354: 28-30.
  • Riley, D., R. McPherson, and L. Wells. 2009. Thrips vectors of TSWV. University of Georgia Coll. Agric. Environ. Sci. Bull. 1354: 16-19.
  • McPherson, R.M. and S. Diffie. 2009. Sampling the tobacco farmscape for thrips vectors of tomato spotted wilt virus. University of Georgia Coll. Agric. Environ. Sci. Spec. Bull. 63-2: 34-37.
  • McPherson, R.M., D. Taylor and N. Roberson. 2009. Insect pest control with foliar applications of insecticides. University of Georgia Coll. Agric. Environ. Sci. Spec. Bull. 63-2: 42-45.
  • McPherson, R.M. and J.M. Moore. 2009. Tobacco splitworm, budworm and hornworm control with selected insecticides. University of Georgia Coll. Agric. Environ. Sci. Spec. Bull. 63-2: 46-47.
  • McPherson, R.M., J.M. Moore, S.S. LaHue, E. Troxell and W. Stephens. 2009. Effects of selected tray drench insecticide treatments on suppressing thrips vectors and TSWV in tobacco. University of Georgia Coll. Agric. Environ. Sci. Spec. Bull. 63-2: 64-65.
  • McPherson, R.M. and W. Stephens. 2009. Effects of tray drench and transplant water insecticide treatments on thrips suppression and TSWV symptom expression in flue-cured tobacco. University of Georgia Coll. Agric. Environ. Sci. Spec. Bull. 63-2: 66-67.
  • McPherson, R.M. 2009. Tobacco insects - Summary of losses from insect damage and cost of control in Georgia, 2007. University of Georgia Agric. Expt. Stn. Misc. Publ. 106: 2pp.
  • McPherson, R.M. and J.M. Moore. 2009. Tobacco plant bed and greenhouse insect control. University of Georgia Coll. Agric. Environ. Sci. Coop. Ext. Serv. Spec. Bull. 28: 1p.
  • McPherson, R.M. and J.M. Moore. 2009. Tobacco field insect control. University of Georgia Coll. Agric. Environ. Sci. Coop. Ext. Serv. Spec. Bull. 28: 4pp.


Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: Tobacco insect pests cost Georgia producers 2.965 million dollars in costs of control and damage in 2008. In addition, another 2 million dollars was reported in losses due to tomato spotted wilt virus (TSWV), a disease that is vectored by thrips. Twenty-four different weed hosts in the tobacco farmscape had a total of 5618 adult thrips collected from them from January through mid-May 2008. Frankliniella fusca, the tobacco thrips, a reported vector of TSWV, was collected from 17 of these plants species. Another vector, F. occidentalis, was collected from blooms from 9 of the host plants. Over 98% of the thrips collected on tobacco foliage were F. fusca. Only 0.9% of the thrips collected on tobacco blooms were F. occidentalis. Most flower thrips were F. tritici, a non-vector thrips species. Thrips movement within the tobacco field occurred between 0900h and 1820h, with most activity (captures on sticky cards) between 1100h and 1600h. Tray drench applications of Admire, Alias, T-Moxx, and other products, applied 3-5 days prior to transplanting, reduced the seasonal incidence of TSWV around 20%. A tray drench treatment of imidacloprid was as effective as acephate foliar sprays in reducing TSWV but much less expensive and more environmentally sound. Tracer, Coragen, Steward, Lannate, Denim, Orthene, Brigadier, and Belt were effective in controlling tobacco hornworms, and budworms. Capture, Orthene, Lannate, Brigadier and an experimental product were effective in controlling tobacco aphids for up to 14 days after the treatments were applied. Selected transplant water and foliar sprays of insecticides reduced the incidence of tobacco splitworms and the number of tunnels in tobacco leaves. Coragen, Brigade, Warrior and Rimon all provided season-long suppression of splitworm damage. Tobacco splitworm pheromone traps were examined for their effectiveness inpredicting pest outbreaks and crop damage. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
This research project has demonstrated that preplant applications of the insecticides imidacloprid and thiamethoxam can significantly reduce the incidence of tomato spotted wilt virus (TSWV) in tobacco, and potentially save growers millions of dollars annually from this disease. This project has also documented that the tobacco thrips is the predominate vector of TSWV in the Georgia tobacco farmscape, but numerous other alternate plant hosts harbor thrips vectors and TSWV innoculum. Several pest management practices have been identified to help manage TSWV. This research project examines insecticides and insecticide combinations annually to provide the most up-to-date, effective, economical, and environmentally sound control options for Georgia producers. However, this project also has documented the widespread development of tobacco budworm resistance to pyrethroid insecticides. Growers will be encouraged to use alternative insecticides when budworm controls are required, to insure effective control of this key pest. Effective chemical control options are also now available for season-long suppression of tobacco splitworms and pheromone traps can be used to predict when splitworm infestations occur in tobacco.

Publications

  • McPherson, R. M. 2008. Thrips monitoring to predict tomato spotted wilt incidence in flue-cured tobacco. Proc. 43rd Tobacco Workers' Conf. 43:1 (Abstract).
  • McPherson, R. M. 2008. Impacts of early-season thrips monitoring and population suppression on the incidence of spotted wilt in flue-cured tobacco. Proc. 43rd Tobacco Workers' Conf. 43:2 (Abstract).
  • McPherson, Robert M., Stan Diffie, Del Taylor and Neal Roberson. 2008. Sampling the tobacco farmscape for thrips vectors of tomato spotted wilt virus. Tobacco Research Report, UGA CAES Spec. Bull. 63: 30-33.
  • McPherson, R. M., Del Taylor and Neal Roberson. 2008. Tobacco hornworm and aphid control with foliar applications of insecticides. Tobacco Research Report, UGA CAES Spec. Bull. 63: 36-37.
  • McPherson, R. M. And J. M. Moore. 2008. Tobacco splitworm control with selected insecticides and impact on spotted wilt expression. Tobacco Research Report, UGA CAES Spec. Bull. 63: 38-39.
  • McPherson, Robert M., J. Michael Moore, Michael G. Stephenson, and Steve S. LaHue. 2008. Effects of selected tray drench insecticide treatments on suppressing thrips vectors and tomato spotted wilt virus symptoms in tobacco. Tobacco Research Report, UGA CAES Spec. Bull. 63: 50-53.
  • McPherson, Robert M. 2008. Influence of early season thrips suppression on tomato spotted wilt virus symptomatic expression in flue-cured tobacco. Tobacco Research Report, UGA CAES Spec. Bull. 63: 60-63.
  • Chen, Yigen, John R. Ruberson and Robert M. McPherson. 2008. Influence of nitrogen fertility level on insect populations, suppression of spotted wilt symptoms and plant growth of flue-cured tobacco. Tobacco Research Report, UGA CAES Spec. Bull. 63: 64-71.


Progress 01/01/07 to 12/31/07

Outputs
Tobacco insect pests cost Georgia producers over 3.0 million dollars in costs of control and damage in 2007. In addition, another 1.2 million dollars was reported in losses due to tomato spotted wilt virus (TSWV), a disease that is vectored by thrips. Sixteen different weed hosts in the tobacco farmscape had a total of 2892 adult thrips collected from them from mid-December 2006 through mid-May 2007. Frankliniella fusca, the tobaco thrips, a reported vector of TSWV, was collected from 9 of these plants species. Another vector, F. occidentalis, was collected from blooms from 10 of the host plants. Over 81% of the thrips collected on tobacco foliage were F. fusca while 2.8% were F. occidentalis. Only 2.3% of the thrips collected on tobacco blooms were F. occidentalis. Most flower thrips were F. tritici, a non-vector thrips species. Thrips movement within the tobacco field occurred between 0900h and 1820h, with most activity (captures on sticky cards) between 1100h and 1600h. Tray drench applications of Admire, Alias, T-Moxx, and an experimental product, applied 3-5 days prior to transplanting, reduced the seasonal incidence of TSWV around 25-30%. Weekly acephate applications for either 6 or 8 weeks after transplanting reduced thrips populations and TSWV symptomatic plants while increasing yields 103 kg/ha compared to the untreated plots. However, a tray drench treatment of imidacloprid was as effective as acephate but much less expensive and more environmentally sound. Intrepid, Tracer, Steward, Lannate, Denim, Orthene, and Capture were effective in controlling tobacco hornworms. Capture, Warrior, Lannate and 3 experimental products were effective in controlling tobacco aphids for up to 14 days after the treatments were applied. Nitrogen fertility levels did not affect the seasonal incidence of TSWV, tobacco budworms, thrips, aphids, or tobacco hornworms when 135 kg/ha of N was applied compared to 0, 37, and 67 kg/ha of N. Yields and value in the highest N rates were higher than the middle two N rates. Selected transplant water and foliar sprays of insecticides reduced the incidence of tobacco splitworms and the number of tunnels in tobacco leaves.

Impacts
This research project has demonstrated that preplant applications of the insecticides imidacloprid and thiamethoxam can significantly reduce the incidence of tomato spotted wilt virus (TSWV) in tobacco, and potentially save growers millions of dollars annually from this disease. This project has also documented that the tobacco thrips is the predominate vector of TSWV in the Georgia tobacco farmscape, but numerous other alternate plant hosts harbor thrips vectors and TSWV innoculum. Suppressing thrips with weekly foliar sprays of acephate for 6 or 8 weeks reduced TSWV. Thus, several pest management practices have been identified to help manage TSWV. This research project examines insecticides and insecticide combinations annually to provide the most up-to-date, effective, economical, and environmentally sound control options for Georgia producers. However, this project also has documented the widespread development of tobacco budworm resistance to pyrethroid insecticides. Growers will be encouraged to use alternative insecticides when budworm controls are required, to insure effective control of this key pest.

Publications

  • McPherson, R. M., J. M. Moore, and A. S. Csinos. 2007. Impact of early-season thrips exclusion and suppression on the incidence of spotted wilt in flue-cured tobacco. 50th CORESTA Congress proc.: 17 (Abstract).
  • McPherson, R. M. 2007. Evaluating foliar insecticides for control of thrips and other insects on snap beans. 2007. Veg. Res.-Ent. Rept. University of Georgia, College of Agric. & Environ. Sci. Coop. Res. Ext. Publ. 10pp.
  • McPherson, R. M. 2007. Managing thrips vectors and spotted wilt symptom expression in flue-cured tobacco. 71st Mtg. Georgia Entomological Society Abstracts: 13.
  • McPherson, R. M. and A. Csinos. 2007. Incidence of thrips and tomato spotted wilt in flue-cured tobacco protected from early season insect pest infestations. Proc. 42nd Tobacco Workers' Conf. 42:43-44 (Abstract).
  • Riley, D. G., A. Chitturi, and R. M. McPherson. 2007. Effect of pine pollen on settling behavior and oviposition in two thrips species. Proc. 42nd Tobacco Workers' Conf. 42:44 (Abstract).
  • McPherson, R. M. and D. C. Jones. 2007. Tobacco insect losses. University of Georgia, College of Agric. & Environ. Sci. Cooperative Research-Extension Publ. 1-2007:3.
  • McPherson, R. M. 2007. Influence of early season thrips suppression on tomato spotted wilt virus symptomatic expression in flue-cured tobacco. University of Georgia, College of Agric. & Environ. Sci. Cooperative Research-Extension Publ. 1-2007: 58-63.
  • McPherson, R. M., D. Taylor and N. Roberson. 2007. Tobacco hornworm and aphid control with foliar applications of insecticides. University of Georgia, College of Agric. & Environ. Sci. Cooperative Research-Extension Publ. 1-2007: 64-70.
  • McPherson, R. M., S. Diffie, D. Taylor and N. Roberson. 2007. Sampling the tobacco farmscape for thrips vectors of tomato spotted wilt virus. University of Georgia, College of Agric. & Environ. Sci Cooperative Research-Extenion Publ. 1-2007: 71-74.
  • Chen, Y., J. R. Ruberson, and R. M. McPherson. 2007. Influence of nitrogen fertility level on insect populations, suppression of tomato spotted wilt virus symptoms and plant growth of flue-cured tobacco. University of Georgia, College of Agric. & Environ. Sci. Cooperative Research-Extension Publ. 1-2007: 51-54.
  • McPherson, R. M., J. M. Moore, M. G. Stephenson, and S. S. LaHue. 2007. Effects of selected tray drench insecticide treatments on tomato spotted wilt virus symptoms and pest management. University of Georgia, College of Agric. & Environ. Sci. Cooperataive Research-Extension Publ. 1-2007: 55-57.


Progress 01/01/06 to 12/31/06

Outputs
Tobacco insect pests cost Georgia producers over $2.3 million in costs of control and damage in 2006. In addition, another $4.9 million was reported in losses due to tomato spotted wilt virus (TSWV), a disease that is vectored by thrips. Twelve different weed hosts in the tobacco farmscape had a total of 2336 adult thrips collected from them from mid-December 2005 through mid-May 2006. Frankliniella fusca, the tobacco thrips, a reported vector of TSWV, was collected from 10 of these plant species. Another vector, F. occidentalis, was collected from blooms from 5 of the host plants. Over 84% of the thrips collected on tobacco foliage were F. fusca while 1.8% were F. occidentalis. Only 2.3% of the thrips collected on tobacco blooms were F. occidentalis. Most flower thrips were F. tritici, a non-vector thrips species. Thrips movement within the tobacco field occurred between 0900h and 1830h , with most activity (captures on sticky cards) between 1100h and 1600h. Tray drench applications of Admire, Alias, T-Moxx, and an experimental, applied 3-5 days prior to transplanting, reduced the seasonal incidence of TSWV around 25-30%. Weekly acephate applications for either 6 or 8 weeks after transplanting reduced thrips populations and TSWV symptomatic plants while increasing yields 417 kg/ha compared to the untreated plots. Intrepid, Tracer, Steward, Lannate, Denim, Orthene, and Capture were effective in controlling tobacco hornworms. Thrips camouflage cages (covering tobacco with various screening material but not excluding thrips) placed over tobacco for up to 8 weeks after transplanting were ineffective in reducing TSWV. Capture, Warrior, Lannate and 3 experimental products were effective in controlling tobacco aphids for up to 14 days after the treatments were applied. Nitrogen fertility levels did not affect the seasonal incidence of TSWV, tobacco budworms, thrips, aphids, or tobacco hornworms when 135 kg/ha of N was applied compared to 0, 37, and 67 kg/ha of N. Yields and value in the highest N rates were actually lower than the middle two N rates due to a higher incidence of TSWV (63% vs 59%) and lower quality of the harvested leaf.

Impacts
This research project has demonstrated that preplant applications of the insecticides imidacloprid and thiamethoxam can significantly reduce the incidence of tomato spotted wilt virus (TSWV) in tobacco, and potentially save growers millions of dollars annually from this disease. This project has also documented that the tobacco thrips is the predominate vector of TSWV in the Georgia tobacco farmscape, but numerous other alternate plant hosts harbor thrips vectors and TSWV innoculum. Suppressing thrips with weekly foliar sprays of acephate for 6 or 8 weeks reduced TSWV. Thus, several pest management practices have been identified to help manage TSWV. This research project examines insecticides and insecticide combinations annually to provide the most up-to-date, effective, economical, and environmentally sound control options for Georgia producers. However, this project also has documented the widespread development of tobacco budworm resistance to pyrethroid insecticides. Growers will be encouraged to use alternative insecticides when budworm controls are required.

Publications

  • McPherson, R. M. 2006. Incidence of thrips and tomato spotted wilt Tospovirus in flue-cured tobacco protected from early-season insect pest infestations. J. Econ. Entomol. 99:764-770.
  • McPherson, R. M. and D. C. Riley. 2006. Monitoring thrips (Thysanoptera: Thripidae) presence in flue-cured tobacco using yellow sticky cards. J. Entomol. Sci. 41:170-178.
  • McPherson, R. M. 2006. Exclusion of thrips with cages and acephate: Impact on the seasonal incidence of spotted wilt symptomatic plants in flue-cured tobacco. Proc. 41st Tobacco Workers Conf. 41:42. (Abstract).
  • McPherson, R. M., J. M. Moore, F. Connelly, J. Jacobs, and D. C. Jones. 2006. Options for managing thrips and tomato spotted wilt virus on flue-cured tobacco. Proc. 41st Tobacco Workers Conf. 41:43 (Abstract).
  • Csinos, A. S., M. G. Stephenson, and R. M. McPherson. 2006. Evaluating planting dates, ASM and imidacloprid for management of TSWV in tobacco. Phytopathology 97 (6 Sup.): Abstract.
  • McPherson, R. M. and S. K. Diffie. 2006. Monitoring thrips vectors in flue-cured tobacco using yellow sticky traps. Proc. 70th Ann. Meeting Ga. Entomol. Soc.:13 (Abstract).
  • McPherson, R. M. and D. C. Jones. 2006. 2005 tobacco insect losses. 2005 Georgia Tobacco Research-Extension Report. UGA-CAES Coop. Res.-Ext. Publ. 1-2006:3.
  • McPherson, R. M., Y. Chen, and J. R. Ruberson. 2006. Influence of nitrogen fertility level on insect populations, suppression of tomato spoted wilt virus symptoms and plant growth of flue-cured tobacco. 2005 Georgia Tobacco Research-Extension Report. UGA-CAES Coop. Res.-Ext. Publ. 1-2006:35-39.
  • McPherson, R. M., M. G. Stephenson, and S. S. LaHue. 2006. Effects of early-season thrips control practices on tomato spotted wilt virus symptoms and pest management. 2005 Georgia Tobacco Research-Extension Report. UGA-CAES Coop. Res.-Ext. Publ. 1-2006:40-45.
  • McPherson, R. M. 2006. Influence of early season thrips suppression on tomato spotted wilt virus sumptomatic expression. 2005 Georgia Tobacco Research-Extension Report. UGA-CAES Coop. Res.-Ext. Publ. 1-2006: 46-51.
  • McPherson, R. M., N. Roberson, and D. Taylor. 2006. Tobacco budworm and hornworm control with foliar applications of insecticides. 2005 Georgia Tobacco Research-Extension Report. UGA-CAES Coop. Res.-Ext. Publ. 1-2006: 52-55.
  • McPherson, R. M., D. Taylor and N. Roberson. 2006. Aphid control on flue-cured tobacco. 2005 Georgia Tobacco Research-Extension Report. UGA-CAES Coop. Res.-Ext. Publ. 1-2006: 56-58.
  • Ruberson, J. R., R. J. Ottens, R. M. McPherson, D. Jones, P. M. Roberts, J. Clark, J. Jacobs, E. McGriff, H. Paradice, D. Stanaland, and T. Varnedore. 2006. Insecticide resistance in the tobacco budworm, Heliothis virescens, in Georgia. 2005 Georgia Tobacco Research-Extension Report. UGA-CAES Coop. Res.-Ext. Publ. 1-2006:59-65.


Progress 01/01/05 to 12/31/05

Outputs
Tobacco insect pests cost Georgia producers over $2.6 million in costs of control and damage in 2005. In addition, another $9.7 million was reported in losses due to tomato spotted wilt virus (TSWV), a disease that is vectored by thrips. Twelve different weed hosts in the tobacco farmscape had a total of 5337 adult thrips collected from them between December 2004 and mid-May 2005. Frankliniella fusca, the tobacco thrips, a reported vector of TSWV, was collected from 10 of these plant species. Another vector, F. occidentalis, was collected from blooms from 6 of the host plants. Thrips movement within the tobacco field occurred between 0900h and 1830h , with most activity (captures on sticky cards) between 1100h and 1600h. Tray drench applications of Admire, Belay, Platinum, and Actigard, applied 3-5 days prior to transplanting, reduced the seasonal incidence of TSWV and increased yields an average of 475 kg/ha. Thrips exclusion cages placed over tobacco plants immediately after transplanting reduced the seasonal incidence of TSWV when cages remained in place for either 4 or 6 weeks after transplanting. Exclusion cages were not effective in reducing TSWV if left in place for only 2 weeks after transplanting. Weekly acephate applications for either 4 or 6 weeks after transplanting reduced thrips populations and TSWV symptomatic plants while increasing yields 350 kg/ha compared to the untreated plots. Intrepid, Tracer, Steward, Lannate, Denim, Orthene, and Pyridalyl were effective in controlling tobacco budworms and hornworms. Resistance monitoring in tobacco budworms collected on tobacco in 6 counties indicated that budworms were 4-49 times more tolerant of certain pyrethroids than historical averages, indicating that resistance is present in Georgia. Foliar sprays of Belay, Provado, Orthene, and TD2480 (new Assail formulation) were effective in controlling tobacco aphids for up to 21 days after the treatments were applied. Nitrogen fertility levels did not affect the seasonal incidence of TSWV, tobacco budworms or thrips; however, there were higher populations of aphids, tobacco hornworms and hoverfly larvae (predators of aphids) when 135 kg/ha of N was applied compared to 0 and 37 kg/ha of N.

Impacts
This research project has demonstrated that preplant applications of the insecticides Admire, Belay, and Platinum can significantly reduce the incidence of tomato spotted wilt virus (TSWV) in tobacco, and potentially save growers millions of dollars annually from this disease. This project has also documented that the tobacco thrips is the predominate vector of TSWV in the Georgia tobacco farmscape, but numerous other alternate plant hosts harbor thrips vectors and TSWV innoculum. Excluding thrips from tobacco during the first 6 weeks after transplanting greatly reduced the incidence of TSWV. Also, suppressing thrips with weekly foliar sprays of acephate for 4 or 6 weeks reduced TSWV. Thus, several pest management practices have been identified to help manage TSWV. This research examines newly developed insecticides and insecticide combinations annually to provide the most up-to-date, effective, economical, and environmentally sound control options for Georgia producers. However, this project also has documented the widespread development of tobacco budworm resistance to pyrethroid insecticides. Growers will be encouraged to use alternative insecticides when budworm controls are required.

Publications

  • McPherson, R. M., N. Roberson, and D. Taylor. 2005. Tobacco budworm and hornworm control with foliar applications of insecticides. 2004 Georgia Tobacco Research-Extension Report. Coop. Res.-Ext. Publ. 1-2005: 47-50.
  • McPherson, R. M. 2005. Influence of early season thrips suppression on tomato spotted wilt virus symptomatic expression. 2004 Georgia Tobacco Research-Extension Report. Coop. Res.-Ext. Publ. 1-2005: 51-58.
  • McPherson, R. M., D. Taylor, and N. Roberson. 2005. Sampling the tobacco farmscape for thrips vectors of tomato spotted wilt virus. 2004 Georgia Tobacco Research-Extension Report. Coop. Res.-Ext. Publ. 1-2005: 59-63.
  • McPherson, R. M., M. G. Stephenson, and S. S. LaHue. 2005. Effects of early season thrips control practices on tomato spotted wilt virus infection and pest management. 2004 Georgia Tobacco Research-Extension Report. Coop. Res.-Ext. Publ. 1-2005: 64-68.
  • McPherson, R. M., D. Taylor, and N. Roberson. 2005. Aphid control on flue-cured tobacco. 2004 Georgia Tobacco Research-Extension Report. Coop. Res.-Ext. Publ. 1-2005: 69-71.
  • McPherson, R. M. 2005. Aphid control on flue-cured tobacco in Georgia, 2004. Arthropod Management Tests 30: F85 (1pp).
  • McPherson, R. M., N. J. Roberson, and J. D. Taylor. 2005. Tobacco budworm and hornworm control on flue-cured tobacco in Georgia, 2004. Arthropod Management Tests 30: F86 (2pp).
  • McPherson, R.M., M.G. Stephenson, S.S. LaHue, and S.W. Mullis. 2005. Impact of early season thrips management on reducing the risks of spotted wilt virus and suppressing aphid populations in flue-cured tobacco. J. Econ. Entomol. 98:129-134.
  • McPherson, R.M., J.M. Moore, M.P. Seagreaves, F. Connelly, and J. Jacobs. 2005. Attempts to suppress tomato spotted wilt virus using selected early season thrips control tactics in flue-cured tobacco. J. Entomol. Sci. 40: 101-104.
  • McPherson, R. M. 2005. Options for managing thrips and tomato spotted wilt on flue-cured tobacco. Proc. XXII International Congress of Entomology. 22: 44 (abstract).
  • McPherson, R. M. 2005. Options for managing thrips and tomato spotted wilt virus on flue-cured tobacco. Phytopathology 96 (6 Sup.): 68 (abstract).
  • Riley, D., R. McPherson, and L. Wells. 2005. Thrips vectors of tomato spotted wilt virus. UGA CAES Tospoviruses in solanaceae and other crops in the coastal plain of Georgia. Research Rept. 704: 13-16.
  • Riley, D., R. McPherson and L. Wells. 2005. Management of thrips vectors of tomato spotted wilt virus. UGA CAES Tospoviruses in solanaceae and other crops in the coastal plain of Georgia. Research Rept. 704: 24-26.
  • McPherson, R. M. and D. C. Jones. 2005. Insect losses in 2004. 2004 Georgia Tobacco Research-Extension Report. Coop. Res.-Ext. Publ. 1-2005:3.


Progress 01/01/04 to 12/31/04

Outputs
Tobacco insect pests cost Georgia producers over $4.7 million in costs of control and damage in 2004. In addition, another $17.3 million was reported in losses due to tomato spotted wilt virus (TSWV), a disease that is vectored by thrips insects. Twelve different weed hosts in the tobacco farmscape had a total of 4728 adult thrips collected from them between December 2003 and mid-May 2004. Frankliniella fusca, the tobacco thrips, a reported vector of TSWV, was collected from all 12 of these plant species. Flower thrips, including another vector F. occidentalis, were collected from 10 of the host plants. Thrips movement within the tobacco field occurred between 9:00 am and 6:30 pm, with most activity (captures on sticky cards) between 11:00 am and 4:00 pm. Tray drench applications of Admire, Belay, Platinum, and Actigard, applied 3-5 days prior to transplanting, reduced the seasonal incidence of TSWV and increased yields an average of 550 kg/ha. Thrips exclusion cages placed over tobacco plants immediately after transplanting reduced the seasonal incidence of TSWV when cages remained in place for either 4 or 6 weeks after transplanting. Exclusion cages were not effective in reducing TSWV if left in place for only two weeks after transplanting. Weekly acephate applications for either 4 or 6 weeks after transplanting reduced thrips populations and TSWV symptomatic plants while increasing yields 379 kg/ha compared to the untreated plots. Intrepid, Tracer, Steward, Lannate, Denim, Orthene, and S-1812 (pyridalyl) were effective in controlling tobacco budworms and hornworms. Dipel and Warrior also were effective on hornworms but not effective on budworms. Resistance monitoring in tobacco budworms collected on tobacco in Tift County indicated that budworms were 13-14 times more tolerant of certain pyrethroids than historical averages, indicating that resistance is present in Georgia. Foliar sprays of Belay, Provado and Orthene were effective in controlling tobacco aphids for up to 34 days after the treatments were applied.

Impacts
This research project has demonstrated that preplant applications of the insecticides Admire, Belay, and Platinum can significantly reduce the incidence of tomato spotted wilt virus (TSWV) in tobacco, and potentially save growers millions of dollars annually from this disease. This project has also documented that the tobacco thrips is the predominate vector of TSWV in the Georgia tobacco farmscape, but numerous other alternate plant hosts harbor thrips vectors and TSWV innoculum. Excluding thrips from tobacco during the first 6 weeks after transplanting greatly reduced the incidence of TSWV. Also, suppressing thrips with weekly foliar sprays of acephate for 4 or 6 weeks also reduced TSWV. Thus, several pest management practices have been identified to help manage TSWV. This research project continues to examine newly developed insecticides and insecticide combinations annually to provide the most up-to-date, effective, economical, and environmentally sound control options for Georgia producers.

Publications

  • McPherson, R.M. and D.D. Jones. 2004. XX. Tobacco Insects, pp. 38-39, in P. Guillebeau, N. Hinkle, and P. Roberts (ed.), Summary of losses from insect damage and costs of control in Georgia, 2002. Ga. Agric. Expt. Stn., Misc. Publ. 106.
  • McPherson, R.M. and D.C. Jones, 2004. 2003 Insect Losses. 2003 Georgia Tobacco Research-Extension Report. Ga. Agric. Expt. Stn. Coop. Res.-Ext. Publ. 1-2004: 3.
  • McPherson, R.M., N.J. Roberson, and J.D. Taylor. 2004. Effectiveness of S-1812 and Orthene in controlling tobacco budworms on tobacco. 2003 Georgia Tobacco Research- Extension Report. Ga. Agric. Expt. Stn. Coop. Res.-Ext. Publ. 1-2004: 66-69.
  • McPherson, R.M., S.S. LaHue, and M.G. Stephenson. 2004. Effects of early-season thrips control practices on tomato spotted wilt virus infection and pest management. 2003 Georgia Tobacco Research-Extension Report. Ga. Agric. Expt. Stn. Coop. Res.-Ext. Publ. 1-2004: 70-73.
  • McPherson, R.M. 2004. Exclusion of thrips with cages and chemicals: Impact on the seasonal incidence of tomato spotted wilt virus infection and pest management. 2003 Georgia Tobacco Research- Extension Report. Ga. Agric. Expt. Stn. Coop. Res.-Ext. Publ. 1-2004: 74-79.
  • McPherson, R.M. 2004. Impact of early-season Admire and Actigard treatments on tomato spotted wilt virus incidence in tobacco. 2003 Georgia Tobacco Research- Extension Report. Ga. Agric. Expt. Stn. Coop. Res.-Ext. Publ. 1-2004: 80-81.
  • McPherson, R.M. 2004. Sampling the tobacco farmscape for thrips vectors of tomato spotted wilt virus. 2003 Georgia Tobacco Research- Extension Report. Ga. Agric. Expt. Stn. Coop. Res.-Ext. Publ. 1-2004: 82-90.
  • McPherson, R.M., M.G. Stephenson, and S.S. LaHue. 2004. Tobacco budworm control with foliar applications of Denim, Tracer, Orthene, and Warrior. 2003 Georgia Tobacco Research- Extension Report. Ga. Agric. Expt. Stn. Coop. Res.-Ext. Publ. 1-2004: 91-93.
  • McPherson, R.M.,N.J. Roberson, and J.D. Taylor. 2004. Tobacco budworm control on flue-cured tobacco in Georgia, 2003. Arthropod Management Tests 29: F96 (2pp).