BIOLOGY AND CONTROL OF ARTHROPOD PESTS OF HORTICULTURAL CROPS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1015619
• Project Start Date: Mar 19, 2018
• Project End Date: Feb 28, 2023
• Program Code: [(N/A)]- (N/A)

Recipient Organization
UNIVERSITY OF FLORIDA
G022 MCCARTY HALL
GAINESVILLE,FL 32611

Performing Department
Gulf Coast Research and Education Center

Non Technical Summary
Florida is a leading producer of horticultural crops, which contribute over a billion dollars annually to the state's economy. In 2015, the value of Florida tomato was over $453 million, and the state's bell pepper production was valued at over $220 million. In 2015, cabbage and strawberries were worth over $33 million and $291 million, respectively (USDA NASS 2016). The insect and mite pests that attack these crops reduce growers' profits and negatively impact the state's economy. Key arthropod pests of Florida horticultural crops include the sweetpotato whitefly, Bemisia tabaci, thrips species (Frankliniella, Thrips, Scirtothrips spp.), broad mites (Polyphagotarsonemus latus), spider mites (Tetranychus spp.) and caterpillar pests. Whiteflies and thrips are among the most devastating pests because of the plant viruses they transmit, particularly to tomato (both whiteflies and thrips), squash and watermelon (whiteflies and aphids).The diversity of crops and overlapping crop seasons that extend from the temperate Panhandle to the subtropical south produce conditions of almost constant pest pressure across the state. With millions of dollars invested in a season's crop, growers begin applying insecticide treatments at-planting and continue through harvest. Of the $10,000 needed to grow an acre of field tomatoes, up to 25% may be spent on pest management (Mossler et al. 2009). Intensive insecticide use across commodities produces a high risk for the development of insecticide resistance among key pests. Overuse of insecticides can be detrimental to the environment and worker safety. In addition, there is evidence that neonicotinoid and other insecticides play a role in the decline of honey bee and bumble bee populations. Producers of high value organic and greenhouse vegetables require pest management solutions that emphasize beneficial arthropods and "softer" biorational insecticides. Providing Florida growers with tools to reduce insecticide use and mitigate the development of insecticide resistance is crucial for the health of the state's horticultural industries.Pest management methods are evaluated in combination in order to reduce over-reliance on insecticides and their negative impacts. Synergistic effects of combining repellant metalized plastic mulches, host plant resistance and biopesticides are evaluated for suppression of virus vectors. Biopesticides tend to exert less selection pressure than conventional insecticides, and so are less likely to contribute to the development of insecticide resistance.Understanding the role of weeds as hosts of pests, diseases and beneficial arthropods is crucial for the development of sustainable pest management programs. Weeds can contribute to a pest problem by serving as a reservoir for pests and diseases, or they can help alleviate pest pressure by providing habitat for predators and parasitoids that suppress pests.While conventional growers rely primarily on chemical control of arthropod pests, there is a need to evaluate alternative approaches to pest suppression because of the potential negative impacts that insecticides may have on worker safety, water quality and non-target organisms. Sustainable approaches to pest suppression include the use of pheromones to monitor pest populations, and for the disruption of mating of pest arthropods, cultural controls such as floating row covers and larger scale protected agriculture (greenhouses and screen houses), and biological control. The use of cultural and biological controls is necessary for growers who have restrictions on insecticide use, such as growers who produce in protected structures, as well as small-scale diversified growers and organic growers.Because of the growing importance of protected agriculture in Florida, there is a need to develop appropriate guidelines for the use of commercially-available biocontrol agents for management of pests of horticultural crops grown in greenhouses, screen houses and high tunnels. The use of crop combining and habitat manipulation to enhance biological control of naturally-occurring and commercial biocontrol agents is a core component of pest management on organic farms and small-scale farms striving to develop sustainable approaches to pest management (Landis et al. 2000, Barbosa et al. 2009). Evaluation of plants that provide resources and habitat for beneficial arthropods in Florida agricultural systems is needed to provide practical guidelines to organic and other growers requiring alternatives to insecticides to manage pests.

Animal Health Component

70%

Research Effort Categories

Basic

30%

Applied

70%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
211	3110	1130	33%
211	5220	1130	34%
212	3110	1160	33%

Knowledge Area
212 - Pathogens and Nematodes Affecting Plants; 211 - Insects, Mites, and Other Arthropods Affecting Plants;

Subject Of Investigation
3110 - Insects; 5220 - Pesticides;

Field Of Science
1130 - Entomology and acarology; 1160 - Pathology;

Keywords

pest management

vegetable pests

whiteflies

thrips

insecticide resistance management

Goals / Objectives
Objective 1? Develop guidelines for management of Bemisia tabaci and B. tabaci-transmitted viruses1. Design insecticide rotations of conventional insecticides the treatment window approach to offset the development of insecticide resistance;2. Evaluate potential of biopesticides to replace or reduce conventional insecticides in field, greenhouse and certified organic vegetable production3. Evaluate integrated approaches that incorporate multiple strategies including repellent mulches, host plant resistance, conservation biocontrol, and both conventional and biological insecticides.Objective 2.Elucidate patterns of resistance and cross resistance among Bemisia tabaci to key insecticides through continued monitoring of field collected populations from across the stateObjective 3? Develop guidelines to improve biological and integrated control of arthropod pests of vegetable crops including thrips, broad mites, spider mites, and caterpillars, particularly diamondback moth (Plutella xylostella).Guidelines are needed for the management of thrips, mites and other arthropod pests using chemical controls that focus on the treatment window approach for designing insecticide rotations, and evaluations of biopesticides. Improved understanding of the integration of conservation biological control and biopesticides will give growers additional pest suppression tools, contribute to insecticide resistance management, and support the development of value added specialty crops in Florida.Objective 4? Improve understanding of how habitat manipulation can be used to enhance biocontrol of arthropod pests and suppress herbivores in horticultural crops.Methods are needed to establish and maintain stable populations of natural enemies that help suppress key pests of Florida's horticultural crops. Increased understanding of how habitat plantings can be used to enhance conservation biocontrol that will enable growers to reduce insecticide applications for management of key pests. This will result in increased savings for growers and contributing to the development of organic and other value-added specialty crop production methods.

Project Methods
Objective 1 - Managing B. tabaci and B. tabaci-transmitted virusesStudies will be carried out in the laboratory, greenhouse, experiment station and on-farm using randomized complete block designs to evaluate the impact of new and established conventional and biological insecticides on densities of whitefly adults, eggs, and immatures, as well as virus transmission and yield. At-plant, drip and foliar treatments will be evaluated. Laboratory colonies of viruliferous whiteflies will be used in greenhouse studies, and field populations of whiteflies will be used in outdoor studies to evaluate different treatments. In addition, tomato varieties and accessions of tomato relatives will be evaluated in collaboration with breeders to evaluate levels of resistance to whiteflies and Tomato Yellow Leaf Curl virus (TYLCV). Common weeds will be tested to determine if they are sources of TYLCV and other important plant pathogens. Similar approaches will be used to develop guidelines to manage B. tabaci-transmitted viruses in cucurbits.Objective 2 - Monitoring insecticide resistance in B. tabaciWhitefly populations are collected from commercial vegetable fields by aspirating adults directly from the crop using a backpack aspirator (BugVac, BioQuip, Rancho Dominguez, CA), and by leaving potted plants of cotton (Delta Pine 143) or tomato (cv. Lanai) in grower fields for a 3-4 day period to allow female whiteflies the opportunity to oviposit on them. These plants are transported to GCREC and placed into organza covered cages; additional cotton plants are added to the cages over time to help increase population levels. A laboratory reared population which has not been exposed to pesticides for many generations is also tested to provide a 'susceptible' reference for comparison.Susceptibility to insecticides is evaluated using a serial dilution method, with dilutions based on labeled field rates for the insecticide being evaluated. Dilutions will range from 0 parts per million (ppm) active ingredient (untreated control) to a concentration three or four-fold the labeled rate. For example, a common insecticide such as imidacloprid (Admire Pro) is tested at 0, 0.1, 1.0, 10, 50, 100 and 200 ppm active ingredient. Individual cotton leaves are treated with one of the 5-7 dilution rates either by dipping or uptake through the petiole if the insecticide is systemic. After treatment, the cotton leaf is placed in a Petri dish with 12-14 whitefly adults from the population that is being tested for susceptibility. After 72 hours, the number of living, moribund and dead whitefly adults is tabulated. Probit analysis (SPSS Statistics for Windows 22.0) is used to calculate the concentration of active ingredient needed to kill 50 percent of the whiteflies tested. This metric, the LC50, is used to compare the relative susceptibility of populations to a given insecticide. The LC50 of a field population is divided by the LC50 of a susceptible laboratory colony to produce a resistance ratio, which indicates the level of resistance relative to a susceptible population. A similar method is used to test susceptibility of whitefly nymphs (juveniles) to insecticides.Objective 3 - Integrated management of arthropod pests of horticultural cropsIntegrated factors are evaluated using replicated split plot and randomized complete block designs at the Gulf Coast Research and Education Center or on-farm with collaborating growers. Plants are grown in 8-inch-high and 32-inch-wide beds of Myakka fine sand, spaced on 5-ft centers and covered with white virtually impermeable plastic mulch. Plants were irrigated and fertilized by a drip irrigation system with two drip tubes per bed. Drench treatments are hand ladled into the plant holes and foliar treatments are applied with a hand-held sprayer with a spray wand outfitted with a nozzle containing a 45-degree core and a number five disc, calibrated to deliver 560 or 840 L per ha depending on the size of the crop. For tractor applied treatments, foliar treatments are applied with a high clearance, self-propelled sprayer, fitted with Albuz orange nozzles, pressurized to 200 psi and calibrated to deliver 560, 840, or 1,122 L per ha depending on crop stage. Data are collected on pest density, virus incidence, yield, and when possible, parasitism and predation by natural enemies. Analysis is carried out on SAS software using PROC ANOVA, PROC MIXED, or GLIMMIX.Objective 4 - Evaluating appropriate banker and habitat plants to enhance biological control of arthropod pests of horticultural cropsA literature survey will be carried out regarding native and introduced plants that show promise as providing habitat and resources for commercially available and endemic biological control agents that prey upon or parasitize key pests of important horticultural crops in Florida. Plants will be evaluated in north, central and south Florida to determine which species are best adapted to the state's distinct regions. Surveys will be carried out using pitfall traps, sticky cards and additional methods, such as sweep nets and aspirators, to collect epigeal predators, natural enemies associated with flowers, and natural enemies associated with alternate prey on candidate habitat plants. This research will focus initially on diversified organic and conventional farms where insecticide use is limited, and the potential to enhance biocontrol is high.

Progress 10/01/20 to 09/30/21

Outputs
Target Audience:Growers, crop protection specialists, members of teh public, industry representatives, students and other researchers. Changes/Problems:The only major change is extensive focus on Megalurothrips usitatus, Asian bean thrips, which is a new invasive pest of legumes established in south Florida. What opportunities for training and professional development has the project provided?The following trainings were given to growers and other members of the public. c. Regional Smith, H. A. 2021. Management of whiteflies and thrips in field vegetables. Invited virtual presentation given to Rutgers Cooperative Extension annual vegetable meeting. 45 participants. d. State Smith, H. A. 2021. Managing invasive pests in an agriculturally diverse state. Virtual presentation given at Virtual Field Day, GCREC, Wimauma, FL, 75 participants. Smith, H. A. 2021. Insecticidal control of silverleaf whitefly, diamondback moth and Asian bean thrips. In-person presentation at Citrus Ag Expo, Fort Myers, FL. 95 participants. Smith, H. A. 2021. Asian bean thrips, Megalurothrips usitatus, a new invasive pest of legumes. In-person presentation given at the Ag Expo (November), GCREC, Wimauma, Fl. 75 participants. Teh following in-service trainings were offered to UF IFAS Extension agents: II. In-Service Trainings 2021. How Insecticides Work, part of the workshop How Pesticides Work. May 5, 2021 UF IFAS Extension Symposium, Gainesville, FL. 80 participants. 2021. IPM Academy, an in-person training for UF IFAS Extension agents offered by multiple faculty from the Department of Entomology and Nematology. Sept 21, UF IFAS Plant Science Research and Education Unit, Citra, FL. 18 participants. How have the results been disseminated to communities of interest?Results have been published in the peer-review articles listed previoulsy and at grower and scientific meetings listed previously. In addition, results have been presented at scientific meetings by me and members of my program: Smith, H. A., and B. Rossitto de Marchi. 2021. Asian bean thrips, Megalurothrips usitatus, a new invasive pest of legumes. Oral presentation at the Annual Meeting of the Entomological Society of America, Denver, CO. ii. National Rossitto De Marchi, B. (p), and H. A. Smith. 2021. Susceptibility of Bemisia tabaci MEAM1 (Hemiptera: Aleyrodidae) to afidopyropen, cyantraniliprole, dinotefuran, flupyradifurone and spirotetramat. Annual meeting of the Entomological Society of America, Denver, CO, USA. Rossitto De Marchi, B. (p), and H. A. Smith. 2019. Surveying bacterial endosymbiont diversity among Bemisia tabaci (Hemiptera: Aleyrodidae) populations in Florida. Annual meeting of the Entomological Society of America, St. Louis, MO, USA, November 2019 Rossitto De Marchi, B. (p), and H. A. Smith. A critical dose bioassay to assess insecticide tolerance among populations of Bemisia tabaci in Florida vegetable fields. Annual meeting of the Entomological Society of America, St. Louis, MO, USA. iii. State Rossitto De Marchi, B. (p), and H. A. Smith. 2019. Bacterial endosymbiont diversity among Bemisia tabaci (Hemiptera: Aleyrodidae) populations in Florida. Annual meeting of the Florida Entomological Society, Jupiter, FL, USA. iv. Local Rossitto De Marchi, B. (p) and H. A. Smith. Asian Bean Thrips identification and damage. Commercial Vegetable Advisory Committee Meeting, Homestead, Florida, September 2021 Munthali, E. (g), S. Lahiri and H. Smith. 2021. Residual effects of cyantraniliprole and chlorantraniliprole on diamondback moth (Plutella xylostella) feeding and survival on cabbage. Poster presented in the student competition at the Ag Expo, GCREC, Nov 2021. What do you plan to do during the next reporting period to accomplish the goals?We are focused on describing the seasonality of Megalurothrips usitatas on snap bean in south Florida nd continuing to test field populations in the lab to determne susceptibility to conventional and biopesticides. We will continue efficacy testing and resistance monitoring for field populations of Bemisia tabaci and Plutella xylostella.

Impacts
What was accomplished under these goals? Objective 1. Research has been published on relative efficacy of major modes of action for managemet of Bemisia tabaci in south Florida. Objective 2. Resistance to spirotetramat in Florida populations of B. tabaci has been identified by my program this year. Objective 3. Management guidelines have been developed for a new invasive pest of legumes, Asian bean thrips, Megalurothrips usitatus.

Publications

• Type: Journal Articles Status: Published Year Published: 2021 Citation: Dunn, T. P., D. E. Champagne, D. G. Riley, H. Smith, J. E. Bennett. 2021. A target site mutation associated with diamide insecticide resistance in the diamondback moth Plutella xylostella (Lepidoptera: Plutellidae) is widespread in south Georgia and Florida populations. Journal of Economic Entomology doi.org/10.1093/jee/toab223. Rossitto De Marchi, B. (p), and H. Smith. 2021. Efficacy of buprofezin, pyriproxyfen and spirotetramat against Bemisia tabaci MEAM1 nymphal field populations in Florida. Crop Protection https://doi.org/10.1016/j.cropro.2021.105756 Smith, H. A., M. Hennessey, A. Furuya (g), E. Munthali (g), B. Rossitto de Marchi (p), and S. Agehara. 2021. Pests of Florida hops: preliminary observations. Florida Entomologist 104: 51-53. https://doi.org/10.1653/024.104.0108. Rossitto De Marchi, B.(p), H. Smith, W. Turechek, and D. Riley. 2021. A maximum dose bioassay to assess efficacy of key insecticides against Bemisia tabaci MEAM1 (Hemiptera: Aleyrodidae). Journal of Economic Entomology. DOI: 10.1093/jee/toab016. Strzyzewski, I. L. (g), J. E. Funderburk, J. M. Renkema, and H. A. Smith. 2021. Characterization of Frankliniella occidentalis and Frankliniella bispinosa (Thysanoptera: Thripidae) injury to strawberry. Journal of Economic Entomology. DOI:10.1093/j22/toaa311.

Progress 10/01/19 to 09/30/20

Outputs
Target Audience:Growers, Extension agents, crop protection professionals, other researchers, students. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?I organized an multifaculty in-service training for UF IFAS Extension agents entitled IPM Academy for a second year in a row. We had eighteen agents partiicipate virtually this year. I was also part of an in-service training in February 2020 that served a few dozen agents and crop protecion professionals. I presented research results at one in-person grower meeting (Florida Watermelon Growers Assoaciation) and three virtual meetings focusing on ornamental plants, whitefly management, and cucurbit plants. In total about 200 particiapnts were involved. In addition, I presente dresults at the virtual annual meeting of teh Entomological Society of America in collaboration with a post-doctoral researcher in my program. How have the results been disseminated to communities of interest?As described above, results have been disseminated throughh peer-review publications, grower meetings, and scientific meetings. What do you plan to do during the next reporting period to accomplish the goals?We will keep assessing insectcide susceptibility to B tabaci and P xylostella. We will focus more on biopesticides and biocontrol for management of P xylostella. We have a new thrips species, Asian bean thrips, in Florida that we are studying from several aspects.We are also focusing on thrips in pepper (Capsicum annuum) this year.

Impacts
What was accomplished under these goals? We published papers describing susceptibility of Bemisia tabaci (MEAM1 and MED) and Plutella xylostella to key insecticides. We have also published studies on the role of biopesticides for managing Bemisia tabaci. We published work last year on integration of host plant resistance, repellent mulches and insectcides for management of B. tabaci, so that objective should probably be removed. Little has been done on improving biocontrol or habitat manipulation, but we will focus more on those objectives for diamondback moth and various thrips species this year and going forward.

Publications

• Type: Journal Articles Status: Accepted Year Published: 2020 Citation: Benge, M., X. Martini. L. M. Diepenbrock and H. A. Smith. 2020. Determining the professional development needs of Florida integrated pest management extension agents. Journal of Extension. 58 (6) Article v58-6rb5. Riley, D., H. A. Smith, J. Bennett, P. Torrance, E. Huffman, A. Sparks Jr., C. Gruver, T. Dunn, and D. Champagne. 2020. Regional survey of diamondback moth (Lepidoptera: Plutellidae) response to maximum dosages of insecticides in Georgia and Florida. Journal of Economic Entomology. doi: 10.1093/jee/toaa125. Smith, H. A. 2020. Biopesticides for management of Bemisia tabaci MEAM1 (Hemiptera: Aleyrodidae) and Tomato yellow leaf curl virus. Journal of Economic Entomology. DOI: 10.1093/jee/toaa131. Rossitto de Marchi, B. (p.), and H. A. Smith. 2020. Bacterial endosymbiont diversity among Bemisia tabaci populations in Florida. Insects. 11, 79; DOI:10.3390/insects11030179. Smith, H. A, D. Shrestha, E. van Santen, Q. Masroor, and A. Wong. 2020. Development of Bemisia tabaci MEAM1 and MED on tomato (Solanum lycopersicum) alone and in a mixed population. Florida Entomologist. 103: 72-79. 10.1653/024.103.0412 Pandey, P. (g.), H. J. McAuslane, and H. A. Smith. 2020. Effects of plants and supplemental prey on establishment of Dicyphus hesperus (Hemiptera: Miridae). Florida Entomologist. 103: 64-67.

Progress 10/01/18 to 09/30/19

Outputs
Target Audience:The target audience includes growers, students, Extension agents, crop consultants, Master gardeners, industry representatives, other plant protection professionsals, and members of the public. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Hands-On Session: "Using treatment intervals for insecticide resistance management." This was a 30 minute interactive session, offered three times, to groups of approximately ten UF/IFAS extension agents, as part of the day long in-service training "IPM Academy 2019." I developed and delivered this IST in collaboration with eight other Entomology/Nematology faculty members. Plant Science and Education Unit (Citra) Sept 2019. 30 participants. 14% knowledge gain. 2019. "How Insecticides Work," one component of the in-service training 'How Pesticides Work,' offered in collaboration with Gary Vallad (Plant Pathology) and Chris Marble (Weed Science) at the 2019 UF/IFAS Extension Symposium May 2019 in Gainesville. 80 participants. Smith, H. A. 2019. Pest management research at GCREC: whiteflies, diamondback moth and spider mites. Ag Expo, Gulf Coast Research and Education Center, Balm, Florida. 200 participants. Smith, H. A. 2019. Spider mites and other pests of Florida hops. Hops Field Day, Gulf Coast Research and Education Center, Balm, Florida. 70 participants. Smith, H. A. 2019. A critical dose bioassay to assess insecticide efficacy: whiteflies and diamondback moth. Citrus Expo, Lee Civic Center, North Ft Myers, Florida. 25 participants. Smith, H. A. 2019. A quick and dirty test for whitefly insecticide efficacy. Beef OBradys, 1303 17th St., Palmetto, FL. 20 participants. Grower meeting organized by Crystal Snodgrass and Lisa Hickey, UF/IFAS Extension Manatee County. How have the results been disseminated to communities of interest?The results have diseminated in the publications and at the meetings outlined above. What do you plan to do during the next reporting period to accomplish the goals?Continue with resistance monitoring for B. tabaci and P. xylostella. Carry out field trials evaluating residual efficacy of diamide insecticides for control of P. xylostella in cabbage. Continue developing predator-based management systems for spider mites on hops. Complete studies evaluating the effect of viruliferous status on B. tabaci. Viruliferous status in this case refers to whether or not the whiteflies are carriers of Tomato yellow leaf curl virus. Complete competition studies of the B and Q biotypes of B tabaci on horticultural crops.

Impacts
What was accomplished under these goals? Progress has been made refining insecticide rotations for Bemisa tabaci and Plutella xylostella based on the treatment interval approach. Incorporation of biopesticides (insecticidal soap for B. tabaci and Bacillus thuringiensis products for P. xylostella) has been advanced. A lab bioassay that tests field populations of B. tabaci nd P. xylostella has been implemented throughout 2019 and used to demosntrate relative susceptibility of these key pests to commonly used insecticides. Surveys of pests an dbeneficial arthropods associated with hops have advanced the ability to manage spider mites using predators on this crop.

Publications

• Type: Journal Articles Status: Published Year Published: 2019 Citation: Smith, H. A., and K. L. Krey. 2019. Three release rates of Dicyphus hesperus (Hemiptera: Miridae) for management of Bemisia tabaci (Hemiptera: Aleyrodidae) on greenhouse tomato. Insects 10, 23; doi:10.3390/insects10070213
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Shrestha, D. (g.), H. J. McAuslane, T. A. Ebert, F. A. Cervantes, S. T. Adkins, H. A. Smith, N. Dufault, and S. E. Webb. 2019. Assessing the temporal effects of Squash vein yellowing virus infection on settling and feeding behavior of Bemisia tabaci (MEAM1) (Hemiptera: Aleyrodidae). Journal of Insect Science 19: 1-7. Doi: 10.1093/jisea/iez036.
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Gill, U., J. W. Scott, R. Shekasteband, E. Ogundiwin, C. Shuit, D. M. Francis, S.-C. Sim, H. A. Smith and S. F. Hutton. 2019. Ty-6, a major begomovirus resistance gene on chromosome 10, is effective against Tomato yellow leaf curl virus and Tomato mottle virus. Theoretical and Applied Genetics https://10.1007/s00122-019-03298-0.

Progress 03/19/18 to 09/30/18

Outputs
Target Audience:The target audience includes growers, students, extension agents, crop consultants, Master gardeners, industry representatives, and members of the public. Changes/Problems:There are no major changes or problems to report. What opportunities for training and professional development has the project provided?We offered the following five trainings, two in Spanish, for growers and allied agricultural industries on identification and management of pests: Smith, H. A. 2018. Basic Insect ID (in Spanish). Palm Beach County extension office, West Palm Beach. Seven participants. Smith, H. A. 2018. Basic Insect ID (in Spanish). Miami Dade County extension office, Homestead. 18 participants. Smith, H. A. 2018. Managing Bemisa tabaci in Florida vegetables. Beef O'Bradys, Parrish, FL.17 participants. Smith, H. A. 2018. Managing diamondback moth. Saint John's County Cooperative Extension Center, East Palatka. 24 participants. Smith, H. A. 2018. Bemisia tabaci biotype B overview. Lippman's Main offices, Immokalee, FL. 40 participants. The following presentations were made to scientific audiences at national and international meetings: Smith, H. A. 2018. Retos para el manejo de la mosca blanca Bemisia tabaci, una plaga global de cultivos agronómicos, hortícolas y ornamentales. 45th Congress of the Colombian Entomological Society, July 11-23, Cali Colombia. Smith, H. A. 2018. The role of biopesticides in managing Bemisia tabaci biotype B in field tomatoes. Annual meeting of the Southeastern Branch of the Entomological Society of America. Orlando, FL. Smith, H. A. 2018. Managing Bemisia tabaci in Florida vegetables. Annual meeting of the Florida Entomological Society, Saint Augustine, FL. How have the results been disseminated to communities of interest?Yes. We have presented to vegetable growers throughout the state and to Spanish speaking nursery growers in south Florida in addition to the scientific audiences listed above. What do you plan to do during the next reporting period to accomplish the goals?We will be focusing on testing early season populations of sweetpotato whitefly from vegetable and ornamental crops in south Florida to determine if populations are resistant to insecticides early in the season. This is a challenge because populations are smaller early in the season. However this is necessary to determine if resistance management guidelines are working. We will be using molecular techniques to look at resistance in both sweetpotao whitefly and diamondback moth populations (the latter in collaboration with the University of Georgia), and we will be using a critical dose bioassay on both pests (whitefly and diamondback moth) to determine the extent of resistance to a broad array of insecticides used across the state.

Impacts
What was accomplished under these goals? We have demonstrated that resistance of B. tabaci MEAM1 to neonicotinoid insecticides continues to be variable, and that populations of B. tabaci MED demsonstrate levels of resistance that are compatible with MEAM1 rather than significantly greater as has been feared. We have demonstrated that in the absence of insecticides B. tabaci MEAM1 has a competitive advantage over MED on tomato. Biopesticides, specifically insecticidal soap and to a lesser extent the microbial insectcide Beauveria bassiana, play a role in managing B. tabaci and in managing the development of insecticide resistance in B. tabaci. Field trials with diamondback moth indicate that at-plant treatment with cyantraniliprole reduces season-long damage compared to insecticide rotations that are initiated with distinct modes of action, such as Bacillus thuringiensis products or insect growth regulators.

Publications

• Type: Book Chapters Status: Published Year Published: 2018 Citation: Vallad, G. E., H. A. Smith, and G. Messelink. 2018. Crop Protection: Pest and Disease Management. Chapter 7 in Tomatoes, 2nd edition (E. Heuvelink, ed.). CABI Publishing. UK.
• Type: Book Chapters Status: Published Year Published: 2018 Citation: . Perring, T. M., P. A. Stansly, T.X. Liu, H. A. Smith and S. A. Andreason. 2018. Whiteflies: biology, ecology, and management in Sustainable Management of Arthropod Pests of Tomato. (W. Wakil, G. E. Brust, and T. Perring eds.). Academic Press, Elsevier. Pp. 73-110.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Smith, H. A., C. A. Nagle, C. M. MacVean, G. E. Vallad, E. van Santen, and S. F. Hutton. 2018. Comparing host plant resistance, repellent mulches, and at-plant insecticides for management of Bemisia tabaci MEAM1 and Tomato yellow leaf curl virus. J. Econ. Ent. Doi: 10.1093/jee/toy333.