David Kerns - Academia.edu (original) (raw)

Papers by David Kerns

Research paper thumbnail of Occurrence and Ear Damage of Helicoverpa zea on Transgenic Bacillus thuringiensis Maize in the Field in Texas, U.S. and Its Susceptibility to Vip3A Protein

Toxins, 2019

The corn earworm, Helicoverpa zea (Boddie), is a major pest of Bacillus thuringiensis (Bt) maize ... more The corn earworm, Helicoverpa zea (Boddie), is a major pest of Bacillus thuringiensis (Bt) maize and cotton in the U.S. Reduced efficacy of Bt plants expressing Cry1 and Cry2 against H. zea has been reported in some areas of the U.S. In this study, we evaluated the occurrence and ear damage of H. zea on transgenic Bt maize expressing Cry proteins or a combination of Vip3A and Cry proteins in the field in Texas in 2018. We found that the occurrence of H. zea larvae and the viable kernel damage area on the ear were not different between non-Bt maize and Bt maize expressing Cry1A.105+Cry2Ab2 and Cry1Ab+Cry1F proteins. A total of 67.5% of the pyramided Bt maize expressing Cry1Ab+Cry1F+Vip3A was damaged by 2nd–4th instar larvae of H. zea. Diet bioassays showed that the resistance ratio against Vip3Aa51 for H. zea obtained from Cry1Ab+Cry1F+Vip3A maize was 20.4 compared to a field population collected from Cry1F+Cry1A.105+Cry2Ab2 maize. Leaf tissue bioassays showed that 7-day survivorship...

Research paper thumbnail of Susceptibility of Cry1F-maize resistant, heterozygous, and susceptible Spodoptera frugiperda to Bt proteins used in the transgenic cotton

Crop Protection, 2017

Fall armyworm, Spodoptera frugiperda (J.E. Smith), is a major target species of Bt maize and Bt c... more Fall armyworm, Spodoptera frugiperda (J.E. Smith), is a major target species of Bt maize and Bt cotton in the United States. Field resistance to Cry1F maize in S. frugiperda has occurred in Puerto Rico, Brazil, and the southeast region of the United States. There is a great concern that the Cry1F-maize resistant S. frugiperda may move to the cotton fields and cause control problems to Bt cotton where both crops are planted. In this study, larval mortality and growth inhibition of Cry1F maize-susceptible (SS),-heterozygous (RS), and-resistant (RR) genotypes of S. frugiperda were evaluated using diet-incorporated bioassays with six Bt proteins that have been used in commercialized and future Bt cotton plants: Cry1F, Cry1Ab, Cry1Ac, Cry2Ab2, Cry2Ae, and Vip3A. Compared to the mortality data, the measuring of growth inhibition was more sensitive in determining Bt susceptibility of the insect to all six Bt proteins. Overall, RS had a similar performance as SS for the six Bt proteins with a resistance ratio of < 5.5-fold. The resistance ratio of RR calculated based on larval growth inhibition was 930-fold for Cry1F, 50.5fold for Cry1Ab, and >172-fold for Cry1Ac. In contrast, all three insect genotypes were susceptible to Cry2Ab2, Cry2Ae, or Vip3A. The results showed that the Cry1F-maize resistant S. frugiperda was cross-resistant to Cry1Ab or Cry1Ac, but not cross-resistant to Cry2Ab2, Cry2Ae, or Vip3A. The strong cross-resistance among Cry1 proteins suggest that it is necessary to plant pyramided cotton traits that contain at least two active Bt genes for Cry1F-resistant S. frugiperda to ensure the continued success of the Bt cotton technology, especially in the areas where Bt resistance has already occurred.

Research paper thumbnail of Adding a Natural Enemy to Respond to Pest Immigration and Delayed Natural Enemy Releases in Augmentative Biological Control

Environmental Entomology, Apr 2, 2021

Abstract Whether increased natural enemy density or adding a second natural enemy species will pr... more Abstract Whether increased natural enemy density or adding a second natural enemy species will provide superior pest suppression in greenhouse augmentative biological control is unknown for many commercially available natural enemy species. In this study, we use sweetpotato whiteflies, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), on poinsettias, Euphorbia pulcherrima Willd. ex Klotzsch (Malpighiales: Euphorbiaceae), to determine whether adding Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) to Eretmocerus eremicus Rose and Zolnerowich (Hymenoptera: Aphelinidae) is better for B. tabaci suppression compared with either natural enemy alone, both with and without challenges with whitefly immigration or delayed natural enemy releases. The number of whiteflies on caged poinsettias treated with different natural enemy release rates (single or double rate), natural enemy species (one or two species), natural enemy delayed release (weeks 4 and 8), and whitefly immigration treatments (introduced at week 4 or week 8) was censused biweekly for 16 wk. Both species used in combination provided similar or better suppression of whiteflies compared with either natural enemy alone. Both species combined also provided superior suppression of whiteflies when challenged with whitefly immigration or delays in natural enemy releases compared with E. eremicus alone. Whitefly immigration or delays in E. eremicus releases did not increase whitefly populations, suggesting that suppression of whiteflies by E. eremicus alone is relatively robust. This study found no evidence for negative interactions between E. eremicus and A. swirskii for suppressing B. tabaci.

Research paper thumbnail of Using Multiple Natural Enemies to Manage Sweetpotato Whiteflies (Hemiptera: Aleyrodidae) in Commercial Poinsettia (Malpighiales: Euphorbiaceae) Production

Journal of Integrated Pest Management, 2021

In this case study, we investigate the efficacy and economics of using two natural enemies in an ... more In this case study, we investigate the efficacy and economics of using two natural enemies in an integrated pest management (IPM) program to manage sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), in commercial poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) production. Two similar greenhouses at each of three different grower locations were designated as either the IPM or the conventional insecticide greenhouses in southeastern United States. In the IPM greenhouses, we released Eretmocerus eremicus (Rose & Zolnerowich) (Hymenoptera: Aphelinidae) weekly and Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) every 4 wk, and selective insecticides were used to treat high whitefly densities as needed. In the conventional greenhouses, growers were autonomous in their insecticide application decisions. All whitefly stages were counted weekly on a maximum of 20 leaves per 50 randomly sampled poinsettias and 50 flagged (i.e., revisited) poinsettias in every greenhouse. Whitefly densities were consistently similar or higher in the IPM greenhouses compared to their conventionally managed counterparts for the duration of the trial. The cost of inputs and labor for whitefly management in the IPM greenhouses was between 0.57-and 3.0fold the cost of conventional management. Our study supports that releasing E. eremicus and A. swirskii can reduce insecticide applications by 25-78% and may be considered a feasible strategy to manage B. tabaci in commercial poinsettia production in place of conventional insecticidal control in southeastern United States.

Research paper thumbnail of Insecticidal Control of Woolly Whiteflies

Four foliar insecticides (Esteem, Provado, Applaud and Assail) and one soil systemic insecticide ... more Four foliar insecticides (Esteem, Provado, Applaud and Assail) and one soil systemic insecticide (Admire) were evaluated for their control of woolly whitefly in lemons. These insecticides were chosen for evaluation because they have demonstrated efficacy to other whitefly species and have little or no impact on whitefly parasitoids. Admire was injected with a single shank about 5-in deep around each tree approximately at the tree’s drip line. All of the foliar insecticides were effective in controlling woolly whitefly. Admire also appeared to have efficacy, but due to inconsistent data on one sample date more testing should be conducted. Six weeks after the beginning of this test, whitefly parasitoids, Eretmocerus comperei or E. dozieri (exact species not certain) reduced the whitefly population across all treatments. Within two more months, no live whiteflies could be found in the test grove, and as of July 15, 2002, there was still no detectable woolly whitefly activity.

Research paper thumbnail of A comparison of repetitive releases of single or multiple natural enemy species on the suppression of Bemisia tabaci infesting poinsettias

Biological Control, Dec 1, 2020

A comparison of repetitive releases of single or multiple natural enemy species on the suppressio... more A comparison of repetitive releases of single or multiple natural enemy species on the suppression of Bemisia tabaci infesting poinsettias, Biological Control (2020), doi:

Research paper thumbnail of Integrated Pest Management of Citrus Mealybug

Foliar-applied insecticides and the soil-applied insecticide, Admire, were evaluated for their ab... more Foliar-applied insecticides and the soil-applied insecticide, Admire, were evaluated for their ability to control citrus mealybug on lemons while having a minimal impact on parasitoids. All of the foliar-applied insecticide exhibited activity towards citrus mealybug. The standard insecticide, Lorsban, performed very well, but since this product is especially harmful to parasitoids it is not considered to have a good fit in IPM programs where parasitoid conservation is emphasized. The currently labeled alternative, Applaud, was an effective treatment and should be considered for citrus mealybug control to avoid destruction of parasitoids. Several experimental insecticides showed promise: NNI-850, NNI-750C and NNI-010. However, NNI-0101 at the lower rate of 0.24 lbs-ai/ac appeared to be weak. The addition of narrow range crop oil, NR-415 at 1.0 gal/ac, appeared to be beneficial for initial mealybug knock-down, especially for the slower acting insecticides such as Applaud. Soil injection of Admire at 16 and 32 oz/ac appeared to have very good activity, but due to variability in the mealybug population, more data should be collected to confirm this finding.

Research paper thumbnail of Control of Early Woolly Whiteflies Infestations with Foliar Insecticides

Five foliar insecticide treatments (Esteem, Provado, Applaud, Assail, and Danitol + Lorsban) were... more Five foliar insecticide treatments (Esteem, Provado, Applaud, Assail, and Danitol + Lorsban) were evaluated for their control of early woolly whitefly infestations in lemons. Esteem and Applaud are insect growth regulators that should have little impact on whitefly parasitoids. The impact of Provado and Assail on whitefly parasitoids is not certain, but at high rates may be detrimental, while Danitol + Lorsban will be especially harmful to parasitoids. The impact of these insecticides on woolly whitefly could not be fully determined in this trial due to the effectiveness of parasitoids, Eretmocerus comperei or E. dozieri (exact species not certain), on controlling the whiteflies in this test. However, other research (not reported here) has indicated that all of the insecticide treatments evaluated have good activity against woolly whitefly. Because parasitoids can be extremely effective in mitigating woolly whiteflies populations during the early phases of colonization, it is recommended that chemical control not be utilized until woolly whitefly colonies are common. However, previous experiences suggest that allowing woolly whitefly populations develop extremely high populations should be avoided.

Research paper thumbnail of Using Multiple Natural Enemies to Manage Sweetpotato Whiteflies (Hemiptera: Aleyrodidae) in Commercial Poinsettia (Malpighiales: Euphorbiaceae) Production

Journal of Integrated Pest Management

In this case study, we investigate the efficacy and economics of using two natural enemies in an ... more In this case study, we investigate the efficacy and economics of using two natural enemies in an integrated pest management (IPM) program to manage sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), in commercial poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) production. Two similar greenhouses at each of three different grower locations were designated as either the IPM or the conventional insecticide greenhouses in southeastern United States. In the IPM greenhouses, we released Eretmocerus eremicus (Rose & Zolnerowich) (Hymenoptera: Aphelinidae) weekly and Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) every 4 wk, and selective insecticides were used to treat high whitefly densities as needed. In the conventional greenhouses, growers were autonomous in their insecticide application decisions. All whitefly stages were counted weekly on a maximum of 20 leaves per 50 randomly sampled poinsettias and 50 flagged (i.e., revisited) poinsettias i...

Research paper thumbnail of Evaluation of Foliar Insecticides Against Thrips on Seedling Cotton, 2012

Research paper thumbnail of Adding a Natural Enemy to Respond to Pest Immigration and Delayed Natural Enemy Releases in Augmentative Biological Control

Environmental Entomology, 2021

Whether increased natural enemy density or adding a second natural enemy species will provide sup... more Whether increased natural enemy density or adding a second natural enemy species will provide superior pest suppression in greenhouse augmentative biological control is unknown for many commercially available natural enemy species. In this study, we use sweetpotato whiteflies, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), on poinsettias, Euphorbia pulcherrima Willd. ex Klotzsch (Malpighiales: Euphorbiaceae), to determine whether adding Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) to Eretmocerus eremicus Rose and Zolnerowich (Hymenoptera: Aphelinidae) is better for B. tabaci suppression compared with either natural enemy alone, both with and without challenges with whitefly immigration or delayed natural enemy releases. The number of whiteflies on caged poinsettias treated with different natural enemy release rates (single or double rate), natural enemy species (one or two species), natural enemy delayed release (weeks 4 and 8), and whitefly immigration treatment...

Research paper thumbnail of A comparison of repetitive releases of single or multiple natural enemy species on the suppression of Bemisia tabaci infesting poinsettias

Biological Control, 2020

A comparison of repetitive releases of single or multiple natural enemy species on the suppressio... more A comparison of repetitive releases of single or multiple natural enemy species on the suppression of Bemisia tabaci infesting poinsettias, Biological Control (2020), doi:

Research paper thumbnail of Efficacy of Experimental Insecticides for Control of Citrus Thrips on Lemons, 2005

Arthropod Management Tests, 2006

Research paper thumbnail of Control of Early Woolly Whiteflies Infestations with Foliar Insecticides 1

Five foliar insecticide treatments (Esteem, Provado, Applaud, Assail, and Danitol + Lorsban) were... more Five foliar insecticide treatments (Esteem, Provado, Applaud, Assail, and Danitol + Lorsban) were evaluated for their control of early woolly whitefly infestations in lemons. Esteem and Applaud are insect growth regulators that should have little impact on whitefly parasitoids. The impact of Provado and Assail on whitefly parasitoids is not certain, but at high rates may be detrimental, while Danitol + Lorsban will be especially harmful to parasitoids. The impact of these insecticides on woolly whitefly could not be fully determined in this trial due to the effectiveness of parasitoids, Eretmocerus comperei or E. dozieri (exact species not certain), on controlling the whiteflies in this test. However, other research (not reported here) has indicated that all of the insecticide treatments evaluated have good activity against woolly whitefly. Because parasitoids can be extremely effective in mitigating woolly whiteflies populations during the early phases of colonization, it is recommended that chemical control not be utilized until woolly whitefly colonies are common. However, previous experiences suggest that allowing woolly whitefly populations develop extremely high populations should be avoided.

Research paper thumbnail of Evaluation of Selected Insecticides for Control of Stink Bugs in Soybean, 2014: Table 1

Arthropod Management Tests, 2015

Soybean j Glycine max redbanded stink bug j Piezodorus guildinii green stink bug j Acrosternum hi... more Soybean j Glycine max redbanded stink bug j Piezodorus guildinii green stink bug j Acrosternum hilare brown stink bug j Euschistus servus * This research was supported by funding provided by Cheminova and BASF.

Research paper thumbnail of Effects of Insecticides on Blooming Grain Sorghum on Sorghum Midge and Sugarcane Aphid Control, 2014

Arthropod Management Tests, 2015

Research paper thumbnail of Effects of Adjuvants on Transform Efficacy Towards Sugarcane Aphid in Grain Sorghum, 2014: Table 1

Arthropod Management Tests, 2015

Research paper thumbnail of Refuge-in-the-Bag Strategy for Managing Insect Resistance to BT Maize

Outlooks on Pest Management, 2015

Research paper thumbnail of Feeding Behavior, Development, and Damage by Biotypes B, C, and E of Schizaphis graminum Homoptera: Aphididae) on 'Wintermalt', and 'Post' Barley

Environmental Entomology, 1988

Page 1. Feeding Behavior., Development., and Damage by Biotypes B.,C.,and E of Schizaphis graminu... more Page 1. Feeding Behavior., Development., and Damage by Biotypes B.,C.,and E of Schizaphis graminum (Homoptera: Aphididae) on 'Wintermalt., and 'Post' Barley DON C. PETERS, DAVID KERNS, G. J. PUTERKA, ANDRON McNEW] ...

Research paper thumbnail of Cry1F Resistance in Fall Armyworm Spodoptera frugiperda: Single Gene versus Pyramided Bt Maize

PLoS ONE, 2014

Evolution of insect resistance to transgenic crops containing Bacillus thuringiensis (Bt) genes i... more Evolution of insect resistance to transgenic crops containing Bacillus thuringiensis (Bt) genes is a serious threat to the sustainability of this technology. However, field resistance related to the reduced efficacy of Bt maize has not been documented in any lepidopteran pest in the mainland U.S. after 18 years of intensive Bt maize planting. Here we report compelling evidence of field resistance in the fall armyworm, Spodoptera frugiperda (J.E. Smith), to Cry1F maize (TC 3507) in the southeastern region of the U.S. An F 2 screen showed a surprisingly high (0.293) Cry1F resistance allele frequency in a population collected in 2011 from non-Bt maize in south Florida. Field populations from non-Bt maize in 2012-2013 exhibited 18.8-fold to .85.4-fold resistance to purified Cry1F protein and those collected from unexpectedly damaged Bt maize plants at several locations in Florida and North Carolina had .85.4-fold resistance. In addition, reduced efficacy and control failure of Cry1F maize against natural populations of S. frugiperda were documented in field trials using Cry1F-based and pyramided Bt maize products in south Florida. The Cry1F-resistant S. frugiperda also showed a low level of crossresistance to Cry1A.105 and related maize products, but not to Cry2Ab2 or Vip3A. The occurrence of Cry1F resistance in the U.S. mainland populations of S. frugiperda likely represents migration of insects from Puerto Rico, indicating the great challenges faced in achieving effective resistance management for long-distance migratory pests like S. frugiperda.

Research paper thumbnail of Occurrence and Ear Damage of Helicoverpa zea on Transgenic Bacillus thuringiensis Maize in the Field in Texas, U.S. and Its Susceptibility to Vip3A Protein

Toxins, 2019

The corn earworm, Helicoverpa zea (Boddie), is a major pest of Bacillus thuringiensis (Bt) maize ... more The corn earworm, Helicoverpa zea (Boddie), is a major pest of Bacillus thuringiensis (Bt) maize and cotton in the U.S. Reduced efficacy of Bt plants expressing Cry1 and Cry2 against H. zea has been reported in some areas of the U.S. In this study, we evaluated the occurrence and ear damage of H. zea on transgenic Bt maize expressing Cry proteins or a combination of Vip3A and Cry proteins in the field in Texas in 2018. We found that the occurrence of H. zea larvae and the viable kernel damage area on the ear were not different between non-Bt maize and Bt maize expressing Cry1A.105+Cry2Ab2 and Cry1Ab+Cry1F proteins. A total of 67.5% of the pyramided Bt maize expressing Cry1Ab+Cry1F+Vip3A was damaged by 2nd–4th instar larvae of H. zea. Diet bioassays showed that the resistance ratio against Vip3Aa51 for H. zea obtained from Cry1Ab+Cry1F+Vip3A maize was 20.4 compared to a field population collected from Cry1F+Cry1A.105+Cry2Ab2 maize. Leaf tissue bioassays showed that 7-day survivorship...

Research paper thumbnail of Susceptibility of Cry1F-maize resistant, heterozygous, and susceptible Spodoptera frugiperda to Bt proteins used in the transgenic cotton

Crop Protection, 2017

Fall armyworm, Spodoptera frugiperda (J.E. Smith), is a major target species of Bt maize and Bt c... more Fall armyworm, Spodoptera frugiperda (J.E. Smith), is a major target species of Bt maize and Bt cotton in the United States. Field resistance to Cry1F maize in S. frugiperda has occurred in Puerto Rico, Brazil, and the southeast region of the United States. There is a great concern that the Cry1F-maize resistant S. frugiperda may move to the cotton fields and cause control problems to Bt cotton where both crops are planted. In this study, larval mortality and growth inhibition of Cry1F maize-susceptible (SS),-heterozygous (RS), and-resistant (RR) genotypes of S. frugiperda were evaluated using diet-incorporated bioassays with six Bt proteins that have been used in commercialized and future Bt cotton plants: Cry1F, Cry1Ab, Cry1Ac, Cry2Ab2, Cry2Ae, and Vip3A. Compared to the mortality data, the measuring of growth inhibition was more sensitive in determining Bt susceptibility of the insect to all six Bt proteins. Overall, RS had a similar performance as SS for the six Bt proteins with a resistance ratio of < 5.5-fold. The resistance ratio of RR calculated based on larval growth inhibition was 930-fold for Cry1F, 50.5fold for Cry1Ab, and >172-fold for Cry1Ac. In contrast, all three insect genotypes were susceptible to Cry2Ab2, Cry2Ae, or Vip3A. The results showed that the Cry1F-maize resistant S. frugiperda was cross-resistant to Cry1Ab or Cry1Ac, but not cross-resistant to Cry2Ab2, Cry2Ae, or Vip3A. The strong cross-resistance among Cry1 proteins suggest that it is necessary to plant pyramided cotton traits that contain at least two active Bt genes for Cry1F-resistant S. frugiperda to ensure the continued success of the Bt cotton technology, especially in the areas where Bt resistance has already occurred.

Research paper thumbnail of Adding a Natural Enemy to Respond to Pest Immigration and Delayed Natural Enemy Releases in Augmentative Biological Control

Environmental Entomology, Apr 2, 2021

Abstract Whether increased natural enemy density or adding a second natural enemy species will pr... more Abstract Whether increased natural enemy density or adding a second natural enemy species will provide superior pest suppression in greenhouse augmentative biological control is unknown for many commercially available natural enemy species. In this study, we use sweetpotato whiteflies, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), on poinsettias, Euphorbia pulcherrima Willd. ex Klotzsch (Malpighiales: Euphorbiaceae), to determine whether adding Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) to Eretmocerus eremicus Rose and Zolnerowich (Hymenoptera: Aphelinidae) is better for B. tabaci suppression compared with either natural enemy alone, both with and without challenges with whitefly immigration or delayed natural enemy releases. The number of whiteflies on caged poinsettias treated with different natural enemy release rates (single or double rate), natural enemy species (one or two species), natural enemy delayed release (weeks 4 and 8), and whitefly immigration treatments (introduced at week 4 or week 8) was censused biweekly for 16 wk. Both species used in combination provided similar or better suppression of whiteflies compared with either natural enemy alone. Both species combined also provided superior suppression of whiteflies when challenged with whitefly immigration or delays in natural enemy releases compared with E. eremicus alone. Whitefly immigration or delays in E. eremicus releases did not increase whitefly populations, suggesting that suppression of whiteflies by E. eremicus alone is relatively robust. This study found no evidence for negative interactions between E. eremicus and A. swirskii for suppressing B. tabaci.

Research paper thumbnail of Using Multiple Natural Enemies to Manage Sweetpotato Whiteflies (Hemiptera: Aleyrodidae) in Commercial Poinsettia (Malpighiales: Euphorbiaceae) Production

Journal of Integrated Pest Management, 2021

In this case study, we investigate the efficacy and economics of using two natural enemies in an ... more In this case study, we investigate the efficacy and economics of using two natural enemies in an integrated pest management (IPM) program to manage sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), in commercial poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) production. Two similar greenhouses at each of three different grower locations were designated as either the IPM or the conventional insecticide greenhouses in southeastern United States. In the IPM greenhouses, we released Eretmocerus eremicus (Rose & Zolnerowich) (Hymenoptera: Aphelinidae) weekly and Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) every 4 wk, and selective insecticides were used to treat high whitefly densities as needed. In the conventional greenhouses, growers were autonomous in their insecticide application decisions. All whitefly stages were counted weekly on a maximum of 20 leaves per 50 randomly sampled poinsettias and 50 flagged (i.e., revisited) poinsettias in every greenhouse. Whitefly densities were consistently similar or higher in the IPM greenhouses compared to their conventionally managed counterparts for the duration of the trial. The cost of inputs and labor for whitefly management in the IPM greenhouses was between 0.57-and 3.0fold the cost of conventional management. Our study supports that releasing E. eremicus and A. swirskii can reduce insecticide applications by 25-78% and may be considered a feasible strategy to manage B. tabaci in commercial poinsettia production in place of conventional insecticidal control in southeastern United States.

Research paper thumbnail of Insecticidal Control of Woolly Whiteflies

Four foliar insecticides (Esteem, Provado, Applaud and Assail) and one soil systemic insecticide ... more Four foliar insecticides (Esteem, Provado, Applaud and Assail) and one soil systemic insecticide (Admire) were evaluated for their control of woolly whitefly in lemons. These insecticides were chosen for evaluation because they have demonstrated efficacy to other whitefly species and have little or no impact on whitefly parasitoids. Admire was injected with a single shank about 5-in deep around each tree approximately at the tree’s drip line. All of the foliar insecticides were effective in controlling woolly whitefly. Admire also appeared to have efficacy, but due to inconsistent data on one sample date more testing should be conducted. Six weeks after the beginning of this test, whitefly parasitoids, Eretmocerus comperei or E. dozieri (exact species not certain) reduced the whitefly population across all treatments. Within two more months, no live whiteflies could be found in the test grove, and as of July 15, 2002, there was still no detectable woolly whitefly activity.

Research paper thumbnail of A comparison of repetitive releases of single or multiple natural enemy species on the suppression of Bemisia tabaci infesting poinsettias

Biological Control, Dec 1, 2020

A comparison of repetitive releases of single or multiple natural enemy species on the suppressio... more A comparison of repetitive releases of single or multiple natural enemy species on the suppression of Bemisia tabaci infesting poinsettias, Biological Control (2020), doi:

Research paper thumbnail of Integrated Pest Management of Citrus Mealybug

Foliar-applied insecticides and the soil-applied insecticide, Admire, were evaluated for their ab... more Foliar-applied insecticides and the soil-applied insecticide, Admire, were evaluated for their ability to control citrus mealybug on lemons while having a minimal impact on parasitoids. All of the foliar-applied insecticide exhibited activity towards citrus mealybug. The standard insecticide, Lorsban, performed very well, but since this product is especially harmful to parasitoids it is not considered to have a good fit in IPM programs where parasitoid conservation is emphasized. The currently labeled alternative, Applaud, was an effective treatment and should be considered for citrus mealybug control to avoid destruction of parasitoids. Several experimental insecticides showed promise: NNI-850, NNI-750C and NNI-010. However, NNI-0101 at the lower rate of 0.24 lbs-ai/ac appeared to be weak. The addition of narrow range crop oil, NR-415 at 1.0 gal/ac, appeared to be beneficial for initial mealybug knock-down, especially for the slower acting insecticides such as Applaud. Soil injection of Admire at 16 and 32 oz/ac appeared to have very good activity, but due to variability in the mealybug population, more data should be collected to confirm this finding.

Research paper thumbnail of Control of Early Woolly Whiteflies Infestations with Foliar Insecticides

Five foliar insecticide treatments (Esteem, Provado, Applaud, Assail, and Danitol + Lorsban) were... more Five foliar insecticide treatments (Esteem, Provado, Applaud, Assail, and Danitol + Lorsban) were evaluated for their control of early woolly whitefly infestations in lemons. Esteem and Applaud are insect growth regulators that should have little impact on whitefly parasitoids. The impact of Provado and Assail on whitefly parasitoids is not certain, but at high rates may be detrimental, while Danitol + Lorsban will be especially harmful to parasitoids. The impact of these insecticides on woolly whitefly could not be fully determined in this trial due to the effectiveness of parasitoids, Eretmocerus comperei or E. dozieri (exact species not certain), on controlling the whiteflies in this test. However, other research (not reported here) has indicated that all of the insecticide treatments evaluated have good activity against woolly whitefly. Because parasitoids can be extremely effective in mitigating woolly whiteflies populations during the early phases of colonization, it is recommended that chemical control not be utilized until woolly whitefly colonies are common. However, previous experiences suggest that allowing woolly whitefly populations develop extremely high populations should be avoided.

Research paper thumbnail of Using Multiple Natural Enemies to Manage Sweetpotato Whiteflies (Hemiptera: Aleyrodidae) in Commercial Poinsettia (Malpighiales: Euphorbiaceae) Production

Journal of Integrated Pest Management

In this case study, we investigate the efficacy and economics of using two natural enemies in an ... more In this case study, we investigate the efficacy and economics of using two natural enemies in an integrated pest management (IPM) program to manage sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), in commercial poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) production. Two similar greenhouses at each of three different grower locations were designated as either the IPM or the conventional insecticide greenhouses in southeastern United States. In the IPM greenhouses, we released Eretmocerus eremicus (Rose & Zolnerowich) (Hymenoptera: Aphelinidae) weekly and Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) every 4 wk, and selective insecticides were used to treat high whitefly densities as needed. In the conventional greenhouses, growers were autonomous in their insecticide application decisions. All whitefly stages were counted weekly on a maximum of 20 leaves per 50 randomly sampled poinsettias and 50 flagged (i.e., revisited) poinsettias i...

Research paper thumbnail of Evaluation of Foliar Insecticides Against Thrips on Seedling Cotton, 2012

Research paper thumbnail of Adding a Natural Enemy to Respond to Pest Immigration and Delayed Natural Enemy Releases in Augmentative Biological Control

Environmental Entomology, 2021

Whether increased natural enemy density or adding a second natural enemy species will provide sup... more Whether increased natural enemy density or adding a second natural enemy species will provide superior pest suppression in greenhouse augmentative biological control is unknown for many commercially available natural enemy species. In this study, we use sweetpotato whiteflies, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), on poinsettias, Euphorbia pulcherrima Willd. ex Klotzsch (Malpighiales: Euphorbiaceae), to determine whether adding Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) to Eretmocerus eremicus Rose and Zolnerowich (Hymenoptera: Aphelinidae) is better for B. tabaci suppression compared with either natural enemy alone, both with and without challenges with whitefly immigration or delayed natural enemy releases. The number of whiteflies on caged poinsettias treated with different natural enemy release rates (single or double rate), natural enemy species (one or two species), natural enemy delayed release (weeks 4 and 8), and whitefly immigration treatment...

Research paper thumbnail of A comparison of repetitive releases of single or multiple natural enemy species on the suppression of Bemisia tabaci infesting poinsettias

Biological Control, 2020

A comparison of repetitive releases of single or multiple natural enemy species on the suppressio... more A comparison of repetitive releases of single or multiple natural enemy species on the suppression of Bemisia tabaci infesting poinsettias, Biological Control (2020), doi:

Research paper thumbnail of Efficacy of Experimental Insecticides for Control of Citrus Thrips on Lemons, 2005

Arthropod Management Tests, 2006

Research paper thumbnail of Control of Early Woolly Whiteflies Infestations with Foliar Insecticides 1

Five foliar insecticide treatments (Esteem, Provado, Applaud, Assail, and Danitol + Lorsban) were... more Five foliar insecticide treatments (Esteem, Provado, Applaud, Assail, and Danitol + Lorsban) were evaluated for their control of early woolly whitefly infestations in lemons. Esteem and Applaud are insect growth regulators that should have little impact on whitefly parasitoids. The impact of Provado and Assail on whitefly parasitoids is not certain, but at high rates may be detrimental, while Danitol + Lorsban will be especially harmful to parasitoids. The impact of these insecticides on woolly whitefly could not be fully determined in this trial due to the effectiveness of parasitoids, Eretmocerus comperei or E. dozieri (exact species not certain), on controlling the whiteflies in this test. However, other research (not reported here) has indicated that all of the insecticide treatments evaluated have good activity against woolly whitefly. Because parasitoids can be extremely effective in mitigating woolly whiteflies populations during the early phases of colonization, it is recommended that chemical control not be utilized until woolly whitefly colonies are common. However, previous experiences suggest that allowing woolly whitefly populations develop extremely high populations should be avoided.

Research paper thumbnail of Evaluation of Selected Insecticides for Control of Stink Bugs in Soybean, 2014: Table 1

Arthropod Management Tests, 2015

Soybean j Glycine max redbanded stink bug j Piezodorus guildinii green stink bug j Acrosternum hi... more Soybean j Glycine max redbanded stink bug j Piezodorus guildinii green stink bug j Acrosternum hilare brown stink bug j Euschistus servus * This research was supported by funding provided by Cheminova and BASF.

Research paper thumbnail of Effects of Insecticides on Blooming Grain Sorghum on Sorghum Midge and Sugarcane Aphid Control, 2014

Arthropod Management Tests, 2015

Research paper thumbnail of Effects of Adjuvants on Transform Efficacy Towards Sugarcane Aphid in Grain Sorghum, 2014: Table 1

Arthropod Management Tests, 2015

Research paper thumbnail of Refuge-in-the-Bag Strategy for Managing Insect Resistance to BT Maize

Outlooks on Pest Management, 2015

Research paper thumbnail of Feeding Behavior, Development, and Damage by Biotypes B, C, and E of Schizaphis graminum Homoptera: Aphididae) on 'Wintermalt', and 'Post' Barley

Environmental Entomology, 1988

Page 1. Feeding Behavior., Development., and Damage by Biotypes B.,C.,and E of Schizaphis graminu... more Page 1. Feeding Behavior., Development., and Damage by Biotypes B.,C.,and E of Schizaphis graminum (Homoptera: Aphididae) on 'Wintermalt., and 'Post' Barley DON C. PETERS, DAVID KERNS, G. J. PUTERKA, ANDRON McNEW] ...

Research paper thumbnail of Cry1F Resistance in Fall Armyworm Spodoptera frugiperda: Single Gene versus Pyramided Bt Maize

PLoS ONE, 2014

Evolution of insect resistance to transgenic crops containing Bacillus thuringiensis (Bt) genes i... more Evolution of insect resistance to transgenic crops containing Bacillus thuringiensis (Bt) genes is a serious threat to the sustainability of this technology. However, field resistance related to the reduced efficacy of Bt maize has not been documented in any lepidopteran pest in the mainland U.S. after 18 years of intensive Bt maize planting. Here we report compelling evidence of field resistance in the fall armyworm, Spodoptera frugiperda (J.E. Smith), to Cry1F maize (TC 3507) in the southeastern region of the U.S. An F 2 screen showed a surprisingly high (0.293) Cry1F resistance allele frequency in a population collected in 2011 from non-Bt maize in south Florida. Field populations from non-Bt maize in 2012-2013 exhibited 18.8-fold to .85.4-fold resistance to purified Cry1F protein and those collected from unexpectedly damaged Bt maize plants at several locations in Florida and North Carolina had .85.4-fold resistance. In addition, reduced efficacy and control failure of Cry1F maize against natural populations of S. frugiperda were documented in field trials using Cry1F-based and pyramided Bt maize products in south Florida. The Cry1F-resistant S. frugiperda also showed a low level of crossresistance to Cry1A.105 and related maize products, but not to Cry2Ab2 or Vip3A. The occurrence of Cry1F resistance in the U.S. mainland populations of S. frugiperda likely represents migration of insects from Puerto Rico, indicating the great challenges faced in achieving effective resistance management for long-distance migratory pests like S. frugiperda.