George Kennedy | North Carolina State University (original) (raw)
Papers by George Kennedy
Journal of the American Society for Horticultural Science
A laboratory procedure for assaying Lycopersicon spp. for resistance to the tobacco hornworm Mand... more A laboratory procedure for assaying Lycopersicon spp. for resistance to the tobacco hornworm Manduca sexta (L.) is described. Results from this procedure, which employed excised foliage from greenhouse grown plants and first instar hornworm larvae from a colony maintained in the laboratory on artificial diet, were similar to those obtained with intact plants, with field collected hornworm larvae, and with field grown resistant plants. The Lycopersicon hirsutum f. glabratum accessions PI 134417 and LA 407 were highly resistant to M. sexta. Resistance was manifest as a significant reduction in larval survival and in weight gained by survivors over a 72 hour period. The interplant variation in larval weight gains within accessions was highly significant, suggesting that most of the accessions tested were segregating for resistance to M. sexta.
Insecticide and Acaricide Tests, 1980
Plots were direct seeded on Jun 1 at the North Carolina State University Central Crops Research S... more Plots were direct seeded on Jun 1 at the North Carolina State University Central Crops Research Station, Clayton, NC. Plots consisted of a single row of tomatoes 20-ft long and 3.5 ft wide, separated within rows by 10—Ft of bare ground and between rows by one unplanted row. Overhead irrigation was supplied as needed. Treatments were replicated 4 times in a randomized complete block experimental design. Foliar sprays were applied using a tractor mounted, high pressure sprayer equipped with 3 hollow cone nozzles/row and delivering 60 gal/acre at 150 psi. Treatments were begun when ca 50% of the plants had set fruit. Applications were made weekly from Jul 26 to Aug 30. Sixty randomly selected ripe fruit/plot were harvested on Aug 31, one day after the last treatment, and 60 more/plot were harvested on Sep 6. All were examined for injury by H. zea.
Journal of Economic Entomology, 2016
Abstract The twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is an impor... more Abstract The twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is an important pest of tomatoes in North Carolina. Resident populations of the predatory mite Phytoseiulus persimilis have recently been detected on field-grown tomatoes in central North Carolina, and potentially can be a useful biological control agent against T. urticae. Laboratory bioassays were used to assess lethal and reproductive effects of 10 insecticides and five fungicides commonly used in commercial tomato production (chlorantraniliprole, spinetoram, permethrin, imidacloprid, dimethoate, dinotefuran, thiamethoxam, bifenthrin, fenpropathrin, lambda-cyhalothrin, azoxystrobin, chlorothalonil, boscalid, cyazofamid, and mancozeb) on P. persimilis adult females and eggs. Insecticides were tested using concentrations equivalent to 1×, 0.5×, and 0.1× of the recommended field rates. Fungicides were tested at the 1× rate only. Dimethoate strongly impacted P. persimilis with high adult mortality, reduced fecundity, and reduced hatch of eggs laid by treated adults, particularly at high concentrations. The pyrethroids lambda-cyhalothrin, bifenthrin, and fenpropathrin were associated with repellency and reproductive effects at high concentrations. Bifenthrin additionally caused increased mortality at high concentrations. Chlorantraniliprole, dinotefuran, and permethrin did not significantly affect mortality or reproduction. Imidacloprid significantly reduced fecundity and egg viability, but was not lethal to adult P. persimilis. Thiamethoxam negatively impacted fecundity at the 1× rate. There were no negative effects associated with fungicide exposure with the exception of mancozeb, which impacted fecundity. Field trials were conducted to explore the in vivo impacts of screened insecticides on P. persimilis populations in the field. Field trials supported the incompatibility of dimethoate with P. persimilis populations.
Journal of Economic Entomology, 1976
Two trap designs, 2 bait dispensers, and 8 synthetic tridecen-, and tridecadien-l-ol acetate isom... more Two trap designs, 2 bait dispensers, and 8 synthetic tridecen-, and tridecadien-l-ol acetate isomers or mixtures were evaluated for survey trapping of adult moths of Phthorimaea operculella (Zeller). Of the trapping techniques tested, highest moth catches were obtained with a water pan trap baited with a rubber cap impregnated with 300 μg of t-4, c-7-C13OAc. Similarly baited Pherocon® IC sticky traps caught fewer moths under conditions of high infestation because their sticky surfaces tended to become saturated with moths. The handling characteristics and longevity of the rubber cap made it more suitable than a solution wick for dispensing attractants. None of the δ-7- or δ-7,11-C13OAc isomers rivaled t-4, c-7-C13OAc in attractant potency, though c-7- and c-7, t-11-C13OAc possess some minor attractant activity. Furthermore, δ-7,11-C13-OAc isomers were not found in extracts of female potato tuberworms.
Journal of Economic Entomology, 1979
In greenhouse studies, apterous turnip aphids, Lipaphis erysimi (Kaltenbach), reared on ‘Shogoin’... more In greenhouse studies, apterous turnip aphids, Lipaphis erysimi (Kaltenbach), reared on ‘Shogoin’ turnip had a longer prereproductive period, produced fewer progeny, and were smaller than their counterparts reared on ‘Purple Top White Glob’ (PTWG) turnip. Similarly, alate aphids reared on radish and placed on turnip as prereproductive adults, produced fewer progeny on Shogoin than on PTWG. Experiments in which apterous aphids were reared on one cultivar and transferred to the other as prereproductive adults suggested that the resistance of Shogoin operates primarily against the reproductive adult turnip aphid. In 3 field plantings, turnip aphids were 3X more abundant on PTWG than on Shogoin in the one planting in which well-established aphid populations were observed. The green peach aphid, Myzus persicae (Sulzer), and the cabbage aphid, Brevicoryne brassicae (L.), were significantly more abundant on Shogoin than on PTWG in one planting, but not in 2 others. Larvae of the diamondback moth, Plutella xylostella (L.), were significantly more abundant on Shogoin than PTWG in 2 of the 3 experimental plantings.
Scientific Reports
Cassava mosaic disease is caused by a complex of whitefly-transmitted begomoviruses, which often ... more Cassava mosaic disease is caused by a complex of whitefly-transmitted begomoviruses, which often occur in co-infections. These viruses have bipartite genomes consisting of DNA-A and DNA-B that are encapsidated into separate virions. Individual viruses exist in plants and whitefly vectors as populations comprising both genome segments, which can occur at different frequencies. Both segments are required for infection, and must be transmitted for virus spread to occur. Cassava plants infected with African cassava mosaic virus (ACMV) and/or East African cassava mosaic Cameroon virus (EACMCV), in which the ratios of DNA-A:DNA-B titers differed between plants, were used to examine how titers of the segments in a plant relate to their respective probabilities of acquisition by whiteflies and to the titers of each segment acquired and subsequently transmitted by whiteflies. The probabilities of acquiring each segment of ACMV did not reflect their relative titers in the source plant but the...
Crop Protection, 2018
Background: Frankliniella fusca (Hinds) resistance to neonicotinoid seed treatments (NSTs) used i... more Background: Frankliniella fusca (Hinds) resistance to neonicotinoid seed treatments (NSTs) used in cotton has created a need for more diverse insecticide options targeting thrips. Alternative insecticides must protect seedlings while they are most vulnerable to F. fusca injury (emergence through five true leaves). In this study, we evaluated non-neonicotinoid foliar insecticide sprays currently registered for use on cotton against a neonicotinoid resistant F. fusca population. Methods: During two-seasons, we compared NSTs (imidacloprid, imidacloprid + thiodicarb, and thiamethoxam) to non-neonicotinoid foliar sprays of acephate, spinetoram, abamectin, cyantraniliprole, and cyantraniliprole + abamectin in field trials to evaluate their efficacy against a neonicotinoid resistant F. fusca population. Applications were made to both early-and full-maturity cotton varieties (Stoneville 4946GLB2 & 6448GLB2) to examine F. fusca larval establishment, plant vigor, and seed cotton yield. Results: With the exception of abamectin, foliar insecticide treatments consistently reduced F. fusca larval numbers and minimized true leaf damage at a level equal to or greater than NSTs. Yield was not affected by insecticide treatment. Non-neonicotinoid foliar sprays have utility in managing neonicotinoid-resistant F. fusca and should be recommended to alleviate selection pressure against NSTs in cotton and unnecessary economic losses due to ineffective NST use against resistant F. fusca populations.
Conservation Biological Control, 1998
... 10 NATURALLY OCCURRING BIOLOGICAL CONTROLS IN GENETICALLY ENGINEEREDCROPS CW Hoy, J. Feldman,... more ... 10 NATURALLY OCCURRING BIOLOGICAL CONTROLS IN GENETICALLY ENGINEEREDCROPS CW Hoy, J. Feldman, F. Gould, GG Kennedy, G. Reed, and JA Wyman I. INTRODUCTION AND OVERVIEW Genetically engineered crops have entered the marketplace. ...
Plant resistance to herbivores and …, 1992
Pest Management Science, 2020
BACKGROUND: Thrips (order Thysanoptera) infestations of cotton seedlings result in plant injury, ... more BACKGROUND: Thrips (order Thysanoptera) infestations of cotton seedlings result in plant injury, increasing the detrimental consequences of other challenges to production agriculture, such as abiotic stress or infestation by other pests. Using Frankliniella fusca as a thrips species of focus, we empirically developed a composite model of thrips phenology and cotton seedling susceptibility to predict site-specific infestation risk so that monitoring and other resources can be allocated efficiently, to optimize the timing of thrips control measures to maximize effectiveness, and to inform stakeholders about the dynamics of thrips infestation and cotton seedling injury at a time when thrips are evolving resistance to commonly-used pesticides. RESULTS: A mixture distribution model of thrips infestation potential, fit to data describing F. fusca adult dispersal in time, proved best for predicting infestations of F. fusca on cotton seedlings. Thrips generations occurring each year as a function of weather are represented as a probability distribution. A model of cotton seedling growth was also developed to predict susceptibility as a function of weather. Combining these two models resulted in a model of seedling injury, which was validated and developed for implementation as a software tool. CONCLUSIONS: Experimental validation of the implemented model demonstrated the utility of its output in predicting infestation risk. Successful implementation and use of the software tool derived from this model was enabled by close cooperation with university extension personnel, agricultural consultants, and growers, underscoring the importance of stakeholder and expert input to the success of applied analytical research.
Journal of Economic Entomology, 1975
With virgin females as bait, 8 different trap designs deployed at 2 heights and 2 orientations we... more With virgin females as bait, 8 different trap designs deployed at 2 heights and 2 orientations were evaluated for their efficiency in capturing adult males of Phthorimaea operculella (Zeller). The Pherocon™ 1C trap was superior to all other designs tested but had a tendency to become coated with dust. Its performance was independent of the heights tested. Although significantly less efficient, the Pherocon™ 1CP and 1CPY (with and without flag) captured numerous males and were less prone to collecting dust. Pherocon 1C traps deployed with mated females were no more attractive to males than unbaited traps. Virgin females between 0 and 6 days post-emergence were most attractive to males; this attraction continued at a lower level for at least 10 days.
PLOS ONE
The term "Akaike's Information Criterion" is misspelled throughout the article. The correct term ... more The term "Akaike's Information Criterion" is misspelled throughout the article. The correct term is "Akaike's Information Criterion."
Arthropod Management Tests, 2012
The objectives of this study were to evaluate the residual effects of early season foliar applica... more The objectives of this study were to evaluate the residual effects of early season foliar applications of Cyazypyr™ on suppression of tomato injury caused by Lepidopteran pests to fresh market tomato fruit in North Carolina. 'Celebrity' tomato plants were transplanted to the field in Apex, North Carolina on Jun 4, 2011. The planting was divided into 5 row plots, each 40 ft long by 4 ft wide (Plot = 0.0045913 acres). Plots were separated within rows by 10 ft of unplanted row and between rows by 3 rows. Plants were separated within rows by an average of 1.5 ft. The treatments were arranged in a RCB design with three replicates. The experimental treatments and application timing are described in Table 1. Applications were directed against early season foliar insect pests and, specifically, fruit-feeding Lepidoptera. All treatments were applied as foliar sprays using a CO 2-powered, back pack sprayer equipped with 3 nozzles (D-3 disk, 25 core) per row operated at 40 psi and calibrated to deliver 30 gal of spray per acre. On Aug 7, 14, 21, and 27 mature green and vine ripe fruit were harvested from the center 2 rows in each plot and examined for damage by fruitworms. The only fruitworm observed in this planting was Helicoverpa zea. The proportion of damaged fruit in samples taken on each harvest date were arcsine square root transformed and subjected to ANOVA with mean separation by Fisher's protected LSD at P<0.05.
PloS one, 2015
Landscape-scale intensification of individual crops and pesticide use that is associated with thi... more Landscape-scale intensification of individual crops and pesticide use that is associated with this intensification is an emerging, environmental problem that is expected to have unequal effects on pests with different lifecycles, host ranges, and dispersal abilities. We investigate if intensification of a single crop in an agroecosystem has a direct effect on insecticide resistance in a specialist insect herbivore. Using a major potato pest, Leptinotarsa decemlineata, we measured imidacloprid (neonicotinoid) resistance in populations across a spatiotemporal crop production gradient where potato production has increased in Michigan and Wisconsin, USA. We found that concurrent estimates of area and temporal frequency of potato production better described patterns of imidacloprid resistance among L. decemlineata populations than general measures of agricultural production (% cropland, landscape diversity). This study defines the effects individual crop rotation patterns can have on spe...
Journal of Economic Entomology, 2003
The sensitivities of a model simulating the evolution of resistance in Helicoverpa zea to Bt toxi... more The sensitivities of a model simulating the evolution of resistance in Helicoverpa zea to Bt toxins in transgenic crops were investigated by examining effects of each of the model parameters on the frequency of resistance alleles after 8 yr. The functional dominance of resistance alleles and the initial frequency of those alleles had a major impact on resistance evolution. The survival of susceptible insects on the transgenic crops and the population dynamics of the insect, driven by winter survival and reproductive rates, were also important. In addition, agricultural practices including the proportion of the acreage planted to corn, and the larval threshold for spraying cotton Þelds affected the R-allele frequency. Many of these important parameters are inherently variable or cannot be measured with accuracy, so model output cannot be interpreted as being a forecast. However, this analysis is useful in focusing empirical research on those aspects of the insectsÕ life system that have the largest effects on resistance development, and indicates ways in which to improve products and agricultural practices to increase the expected time to resistance. The model can thus be used as a scientiÞc basis for devising a robust resistance management strategy for Bt crops.
Entomologia Experimentalis et Applicata, 1989
... composi-tion of their sex pheromone in the Eastern seaboard region (Card6 etal., 1975; Durant... more ... composi-tion of their sex pheromone in the Eastern seaboard region (Card6 etal., 1975; Durant &amp; Manley, 1987; Durant etal., 1986; Kennedy &amp; Anderson, 1980; Roelofs et ... In August of 1986, 300 ECB larvae were field collected from maize in Fuquay-Varina, NC (35 ~ N36&#x27;lat.). ...
Entomologia Experimentalis et Applicata, 1989
ABSTRACT
Entomologia Experimentalis et Applicata, 1992
... PC Ellsworth, 1 JR Bradley, Jr., GG Kennedy, RP Patterson&#39;- &amp; RE Stin... more ... PC Ellsworth, 1 JR Bradley, Jr., GG Kennedy, RP Patterson&#39;- &amp; RE Stinner Department of Entomology, and 2Department of Crop Science, North ... Maize (Zea mays L.) plants were arranged in a randomized complete block design in the field over two years in North Carolina (NC). ...
Journal of the American Society for Horticultural Science
A laboratory procedure for assaying Lycopersicon spp. for resistance to the tobacco hornworm Mand... more A laboratory procedure for assaying Lycopersicon spp. for resistance to the tobacco hornworm Manduca sexta (L.) is described. Results from this procedure, which employed excised foliage from greenhouse grown plants and first instar hornworm larvae from a colony maintained in the laboratory on artificial diet, were similar to those obtained with intact plants, with field collected hornworm larvae, and with field grown resistant plants. The Lycopersicon hirsutum f. glabratum accessions PI 134417 and LA 407 were highly resistant to M. sexta. Resistance was manifest as a significant reduction in larval survival and in weight gained by survivors over a 72 hour period. The interplant variation in larval weight gains within accessions was highly significant, suggesting that most of the accessions tested were segregating for resistance to M. sexta.
Insecticide and Acaricide Tests, 1980
Plots were direct seeded on Jun 1 at the North Carolina State University Central Crops Research S... more Plots were direct seeded on Jun 1 at the North Carolina State University Central Crops Research Station, Clayton, NC. Plots consisted of a single row of tomatoes 20-ft long and 3.5 ft wide, separated within rows by 10—Ft of bare ground and between rows by one unplanted row. Overhead irrigation was supplied as needed. Treatments were replicated 4 times in a randomized complete block experimental design. Foliar sprays were applied using a tractor mounted, high pressure sprayer equipped with 3 hollow cone nozzles/row and delivering 60 gal/acre at 150 psi. Treatments were begun when ca 50% of the plants had set fruit. Applications were made weekly from Jul 26 to Aug 30. Sixty randomly selected ripe fruit/plot were harvested on Aug 31, one day after the last treatment, and 60 more/plot were harvested on Sep 6. All were examined for injury by H. zea.
Journal of Economic Entomology, 2016
Abstract The twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is an impor... more Abstract The twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is an important pest of tomatoes in North Carolina. Resident populations of the predatory mite Phytoseiulus persimilis have recently been detected on field-grown tomatoes in central North Carolina, and potentially can be a useful biological control agent against T. urticae. Laboratory bioassays were used to assess lethal and reproductive effects of 10 insecticides and five fungicides commonly used in commercial tomato production (chlorantraniliprole, spinetoram, permethrin, imidacloprid, dimethoate, dinotefuran, thiamethoxam, bifenthrin, fenpropathrin, lambda-cyhalothrin, azoxystrobin, chlorothalonil, boscalid, cyazofamid, and mancozeb) on P. persimilis adult females and eggs. Insecticides were tested using concentrations equivalent to 1×, 0.5×, and 0.1× of the recommended field rates. Fungicides were tested at the 1× rate only. Dimethoate strongly impacted P. persimilis with high adult mortality, reduced fecundity, and reduced hatch of eggs laid by treated adults, particularly at high concentrations. The pyrethroids lambda-cyhalothrin, bifenthrin, and fenpropathrin were associated with repellency and reproductive effects at high concentrations. Bifenthrin additionally caused increased mortality at high concentrations. Chlorantraniliprole, dinotefuran, and permethrin did not significantly affect mortality or reproduction. Imidacloprid significantly reduced fecundity and egg viability, but was not lethal to adult P. persimilis. Thiamethoxam negatively impacted fecundity at the 1× rate. There were no negative effects associated with fungicide exposure with the exception of mancozeb, which impacted fecundity. Field trials were conducted to explore the in vivo impacts of screened insecticides on P. persimilis populations in the field. Field trials supported the incompatibility of dimethoate with P. persimilis populations.
Journal of Economic Entomology, 1976
Two trap designs, 2 bait dispensers, and 8 synthetic tridecen-, and tridecadien-l-ol acetate isom... more Two trap designs, 2 bait dispensers, and 8 synthetic tridecen-, and tridecadien-l-ol acetate isomers or mixtures were evaluated for survey trapping of adult moths of Phthorimaea operculella (Zeller). Of the trapping techniques tested, highest moth catches were obtained with a water pan trap baited with a rubber cap impregnated with 300 μg of t-4, c-7-C13OAc. Similarly baited Pherocon® IC sticky traps caught fewer moths under conditions of high infestation because their sticky surfaces tended to become saturated with moths. The handling characteristics and longevity of the rubber cap made it more suitable than a solution wick for dispensing attractants. None of the δ-7- or δ-7,11-C13OAc isomers rivaled t-4, c-7-C13OAc in attractant potency, though c-7- and c-7, t-11-C13OAc possess some minor attractant activity. Furthermore, δ-7,11-C13-OAc isomers were not found in extracts of female potato tuberworms.
Journal of Economic Entomology, 1979
In greenhouse studies, apterous turnip aphids, Lipaphis erysimi (Kaltenbach), reared on ‘Shogoin’... more In greenhouse studies, apterous turnip aphids, Lipaphis erysimi (Kaltenbach), reared on ‘Shogoin’ turnip had a longer prereproductive period, produced fewer progeny, and were smaller than their counterparts reared on ‘Purple Top White Glob’ (PTWG) turnip. Similarly, alate aphids reared on radish and placed on turnip as prereproductive adults, produced fewer progeny on Shogoin than on PTWG. Experiments in which apterous aphids were reared on one cultivar and transferred to the other as prereproductive adults suggested that the resistance of Shogoin operates primarily against the reproductive adult turnip aphid. In 3 field plantings, turnip aphids were 3X more abundant on PTWG than on Shogoin in the one planting in which well-established aphid populations were observed. The green peach aphid, Myzus persicae (Sulzer), and the cabbage aphid, Brevicoryne brassicae (L.), were significantly more abundant on Shogoin than on PTWG in one planting, but not in 2 others. Larvae of the diamondback moth, Plutella xylostella (L.), were significantly more abundant on Shogoin than PTWG in 2 of the 3 experimental plantings.
Scientific Reports
Cassava mosaic disease is caused by a complex of whitefly-transmitted begomoviruses, which often ... more Cassava mosaic disease is caused by a complex of whitefly-transmitted begomoviruses, which often occur in co-infections. These viruses have bipartite genomes consisting of DNA-A and DNA-B that are encapsidated into separate virions. Individual viruses exist in plants and whitefly vectors as populations comprising both genome segments, which can occur at different frequencies. Both segments are required for infection, and must be transmitted for virus spread to occur. Cassava plants infected with African cassava mosaic virus (ACMV) and/or East African cassava mosaic Cameroon virus (EACMCV), in which the ratios of DNA-A:DNA-B titers differed between plants, were used to examine how titers of the segments in a plant relate to their respective probabilities of acquisition by whiteflies and to the titers of each segment acquired and subsequently transmitted by whiteflies. The probabilities of acquiring each segment of ACMV did not reflect their relative titers in the source plant but the...
Crop Protection, 2018
Background: Frankliniella fusca (Hinds) resistance to neonicotinoid seed treatments (NSTs) used i... more Background: Frankliniella fusca (Hinds) resistance to neonicotinoid seed treatments (NSTs) used in cotton has created a need for more diverse insecticide options targeting thrips. Alternative insecticides must protect seedlings while they are most vulnerable to F. fusca injury (emergence through five true leaves). In this study, we evaluated non-neonicotinoid foliar insecticide sprays currently registered for use on cotton against a neonicotinoid resistant F. fusca population. Methods: During two-seasons, we compared NSTs (imidacloprid, imidacloprid + thiodicarb, and thiamethoxam) to non-neonicotinoid foliar sprays of acephate, spinetoram, abamectin, cyantraniliprole, and cyantraniliprole + abamectin in field trials to evaluate their efficacy against a neonicotinoid resistant F. fusca population. Applications were made to both early-and full-maturity cotton varieties (Stoneville 4946GLB2 & 6448GLB2) to examine F. fusca larval establishment, plant vigor, and seed cotton yield. Results: With the exception of abamectin, foliar insecticide treatments consistently reduced F. fusca larval numbers and minimized true leaf damage at a level equal to or greater than NSTs. Yield was not affected by insecticide treatment. Non-neonicotinoid foliar sprays have utility in managing neonicotinoid-resistant F. fusca and should be recommended to alleviate selection pressure against NSTs in cotton and unnecessary economic losses due to ineffective NST use against resistant F. fusca populations.
Conservation Biological Control, 1998
... 10 NATURALLY OCCURRING BIOLOGICAL CONTROLS IN GENETICALLY ENGINEEREDCROPS CW Hoy, J. Feldman,... more ... 10 NATURALLY OCCURRING BIOLOGICAL CONTROLS IN GENETICALLY ENGINEEREDCROPS CW Hoy, J. Feldman, F. Gould, GG Kennedy, G. Reed, and JA Wyman I. INTRODUCTION AND OVERVIEW Genetically engineered crops have entered the marketplace. ...
Plant resistance to herbivores and …, 1992
Pest Management Science, 2020
BACKGROUND: Thrips (order Thysanoptera) infestations of cotton seedlings result in plant injury, ... more BACKGROUND: Thrips (order Thysanoptera) infestations of cotton seedlings result in plant injury, increasing the detrimental consequences of other challenges to production agriculture, such as abiotic stress or infestation by other pests. Using Frankliniella fusca as a thrips species of focus, we empirically developed a composite model of thrips phenology and cotton seedling susceptibility to predict site-specific infestation risk so that monitoring and other resources can be allocated efficiently, to optimize the timing of thrips control measures to maximize effectiveness, and to inform stakeholders about the dynamics of thrips infestation and cotton seedling injury at a time when thrips are evolving resistance to commonly-used pesticides. RESULTS: A mixture distribution model of thrips infestation potential, fit to data describing F. fusca adult dispersal in time, proved best for predicting infestations of F. fusca on cotton seedlings. Thrips generations occurring each year as a function of weather are represented as a probability distribution. A model of cotton seedling growth was also developed to predict susceptibility as a function of weather. Combining these two models resulted in a model of seedling injury, which was validated and developed for implementation as a software tool. CONCLUSIONS: Experimental validation of the implemented model demonstrated the utility of its output in predicting infestation risk. Successful implementation and use of the software tool derived from this model was enabled by close cooperation with university extension personnel, agricultural consultants, and growers, underscoring the importance of stakeholder and expert input to the success of applied analytical research.
Journal of Economic Entomology, 1975
With virgin females as bait, 8 different trap designs deployed at 2 heights and 2 orientations we... more With virgin females as bait, 8 different trap designs deployed at 2 heights and 2 orientations were evaluated for their efficiency in capturing adult males of Phthorimaea operculella (Zeller). The Pherocon™ 1C trap was superior to all other designs tested but had a tendency to become coated with dust. Its performance was independent of the heights tested. Although significantly less efficient, the Pherocon™ 1CP and 1CPY (with and without flag) captured numerous males and were less prone to collecting dust. Pherocon 1C traps deployed with mated females were no more attractive to males than unbaited traps. Virgin females between 0 and 6 days post-emergence were most attractive to males; this attraction continued at a lower level for at least 10 days.
PLOS ONE
The term "Akaike's Information Criterion" is misspelled throughout the article. The correct term ... more The term "Akaike's Information Criterion" is misspelled throughout the article. The correct term is "Akaike's Information Criterion."
Arthropod Management Tests, 2012
The objectives of this study were to evaluate the residual effects of early season foliar applica... more The objectives of this study were to evaluate the residual effects of early season foliar applications of Cyazypyr™ on suppression of tomato injury caused by Lepidopteran pests to fresh market tomato fruit in North Carolina. 'Celebrity' tomato plants were transplanted to the field in Apex, North Carolina on Jun 4, 2011. The planting was divided into 5 row plots, each 40 ft long by 4 ft wide (Plot = 0.0045913 acres). Plots were separated within rows by 10 ft of unplanted row and between rows by 3 rows. Plants were separated within rows by an average of 1.5 ft. The treatments were arranged in a RCB design with three replicates. The experimental treatments and application timing are described in Table 1. Applications were directed against early season foliar insect pests and, specifically, fruit-feeding Lepidoptera. All treatments were applied as foliar sprays using a CO 2-powered, back pack sprayer equipped with 3 nozzles (D-3 disk, 25 core) per row operated at 40 psi and calibrated to deliver 30 gal of spray per acre. On Aug 7, 14, 21, and 27 mature green and vine ripe fruit were harvested from the center 2 rows in each plot and examined for damage by fruitworms. The only fruitworm observed in this planting was Helicoverpa zea. The proportion of damaged fruit in samples taken on each harvest date were arcsine square root transformed and subjected to ANOVA with mean separation by Fisher's protected LSD at P<0.05.
PloS one, 2015
Landscape-scale intensification of individual crops and pesticide use that is associated with thi... more Landscape-scale intensification of individual crops and pesticide use that is associated with this intensification is an emerging, environmental problem that is expected to have unequal effects on pests with different lifecycles, host ranges, and dispersal abilities. We investigate if intensification of a single crop in an agroecosystem has a direct effect on insecticide resistance in a specialist insect herbivore. Using a major potato pest, Leptinotarsa decemlineata, we measured imidacloprid (neonicotinoid) resistance in populations across a spatiotemporal crop production gradient where potato production has increased in Michigan and Wisconsin, USA. We found that concurrent estimates of area and temporal frequency of potato production better described patterns of imidacloprid resistance among L. decemlineata populations than general measures of agricultural production (% cropland, landscape diversity). This study defines the effects individual crop rotation patterns can have on spe...
Journal of Economic Entomology, 2003
The sensitivities of a model simulating the evolution of resistance in Helicoverpa zea to Bt toxi... more The sensitivities of a model simulating the evolution of resistance in Helicoverpa zea to Bt toxins in transgenic crops were investigated by examining effects of each of the model parameters on the frequency of resistance alleles after 8 yr. The functional dominance of resistance alleles and the initial frequency of those alleles had a major impact on resistance evolution. The survival of susceptible insects on the transgenic crops and the population dynamics of the insect, driven by winter survival and reproductive rates, were also important. In addition, agricultural practices including the proportion of the acreage planted to corn, and the larval threshold for spraying cotton Þelds affected the R-allele frequency. Many of these important parameters are inherently variable or cannot be measured with accuracy, so model output cannot be interpreted as being a forecast. However, this analysis is useful in focusing empirical research on those aspects of the insectsÕ life system that have the largest effects on resistance development, and indicates ways in which to improve products and agricultural practices to increase the expected time to resistance. The model can thus be used as a scientiÞc basis for devising a robust resistance management strategy for Bt crops.
Entomologia Experimentalis et Applicata, 1989
... composi-tion of their sex pheromone in the Eastern seaboard region (Card6 etal., 1975; Durant... more ... composi-tion of their sex pheromone in the Eastern seaboard region (Card6 etal., 1975; Durant &amp; Manley, 1987; Durant etal., 1986; Kennedy &amp; Anderson, 1980; Roelofs et ... In August of 1986, 300 ECB larvae were field collected from maize in Fuquay-Varina, NC (35 ~ N36&#x27;lat.). ...
Entomologia Experimentalis et Applicata, 1989
ABSTRACT
Entomologia Experimentalis et Applicata, 1992
... PC Ellsworth, 1 JR Bradley, Jr., GG Kennedy, RP Patterson&#39;- &amp; RE Stin... more ... PC Ellsworth, 1 JR Bradley, Jr., GG Kennedy, RP Patterson&#39;- &amp; RE Stinner Department of Entomology, and 2Department of Crop Science, North ... Maize (Zea mays L.) plants were arranged in a randomized complete block design in the field over two years in North Carolina (NC). ...