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David I. Shapiro-ilan - One of the best experts on this subject based on the ideXlab platform.
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Establishment of Beauveria bassiana as a fungal endophyte in pecan (Carya illinoinensis) seedlings and its virulence against pecan insect pests
Biological Control, 2020Co-Authors: Tshimangadzo Ramakuwela, Lenny Wells, Justin Hatting, Clive H. Bock, Fernando E. Vega, George N. Mbata, David I. Shapiro-ilanAbstract:Abstract Pecan (Carya illinoinensis) is an important crop in the USA, which produces approximately 55% of the world’s pecans. Several insect pests and various plant diseases reduce crop yield directly destroying nutmeats, or indirectly through effects on foliage and shucks, reducing photosynthesis. Beauveria bassiana is a well-studied, commercialized fungal entomopathogen that when applied inundatively is an effective biocontrol agent against certain pecan pests. In addition to being used in inundative biocontrol, B. bassiana can exist as an endophyte in many plant species and has been shown in some cases to reduce pest damage when present as an endophyte. The potential for B. bassiana to exist as an endophyte in pecan had not been explored previously. We tested whether B. bassiana could endophytically colonize pecan seedlings by seed soaking, seed coating and soil drenching. Results indicated that B. bassiana became established in the roots, leaves and stems of pecan seedlings. Establishment was verified using molecular techniques as well as completing Koch’s postulates on the re-isolated fungus, infecting two susceptible insect hosts (Galleria mellonella and Tenebrio molitor) and a target pest (Curculio Caryae). Subsequently we explored whether the established endophytic fungus suppressed two pecan aphid species. In a leaf-disc assay, populations of two pecan aphids (Melanocallis Caryaefoliae and Monellia caryella) were reduced when placed on leaves of pecan that were colonized endophytically with B. bassiana, relative to control leaves. Our study demonstrates the ability to establish endophytic B. bassiana in pecan and the potential to apply this capability in pecan pest management. Additional research is needed to determine the utility of the endophytic approach against various insect and plant pathogens and to measure efficacy under field conditions.
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Pheromone extracts act as boosters for entomopathogenic nematodes efficacy
Journal of invertebrate pathology, 2019Co-Authors: Camila Oliveira-hofman, Fatma Kaplan, Glen Stevens, Edwin E. Lewis, Hans T. Alborn, Abigail Perret-gentil, David I. Shapiro-ilanAbstract:Inconsistency in entomopathogenic nematode (EPN) efficacy is still one of the biggest challenges for the wider adoption of EPNs as biocontrol agents. Previous studies demonstrated that extracts from EPN-infected hosts enhance dispersal and efficacy, two key factors in success of EPNs. Some active components in the insect host cadavers responsible for dispersal, ascarosides, have been identified as nematode pheromones. We hypothesized that pheromone extracts increase dispersal of EPN infective juveniles (IJs) leading to increased efficacy. First, we determined whether pheromone extracts improved IJ movement/dispersal in soil columns baited with Tenebrio molitor larvae. We found that pheromone extracts induced higher numbers of Steinernema carpocapsae and Steinernema feltiae IJs to move towards T. molitor larvae in the bottom of the column compared to IJs treated with infected cadaver macerate and water, positive and negative controls, respectively. Furthermore, the number of S. carpocapsae IJs that invaded T. molitor larvae was higher for the pheromone extract treatment than the controls. S. feltiae IJs that were pretreated with pheromone extracts and macerate (positive control) infected T. molitor at the same rate but invasion was superior to IJs that were treated with water. Consistent with the soil column tests, both S. carpocapsae and S. feltiae IJs treated with pheromone extracts performed better in killing larvae of two economically important insect larvae, pecan weevil, Curculio Caryae, and black soldier fly, Hermetia illucens, in greenhouse tests compared to IJs treated with water. We demonstrated pheromone-mediated behavioral manipulation of a biological control agent to enhance pest control potential. Conceivably, nematodes can be exposed to efficacy-enhancing pheromones prior to field application.
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Control of Pecan Weevil With Microbial Biopesticides.
Environmental entomology, 2017Co-Authors: David I. Shapiro-ilan, Ted E. Cottrell, Lenny Wells, Clive H. Bock, Kim Mai, Debbie Boykin, William G. Hudson, Russell F. MizellAbstract:The pecan weevil, Curculio Caryae (Horn) (Coleoptera: Curculionidae), is a key pest of pecans Carya illinoinensis ([Wangenh.] K. Koch) (Fagales: Juglandaceae). Control recommendations rely on broad spectrum chemical insecticides. Due to regulatory and environmental concerns, effective alternatives for C. Caryae control must be sought for pecan production in conventional and organic systems. We explored the use of microbial biopesticides for control of C. Caryae in Georgia pecan orchards. Three experiments were conducted. The first investigated an integrated microbial control approach in an organic system at two locations. Three microbial agents, Grandevo (based on byproducts of the bacterium Chromobacterium subtsugae Martin, Gundersen-Rindal, Blackburn & Buyer), the entomopathogenic nematode Steinernema carpocapsae (Weiser), and entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin, were applied to each treatment plot (0.6 ha) at different times during the season. A second experiment compared the effects of S. carpocapsae and B. bassiana applied as single treatments relative to application of both agents (at different times); survival of C. Caryae was assessed approximately 11 mo after larvae were added to pots sunk in an organic pecan orchard. In a conventional orchard (with 1.0 ha plots), the third experiment compared Grandevo applications to a commonly used regime of chemical insecticides (carbaryl alternated with a pyrethroid). All experiments were repeated in consecutive years. The combined pest management tactic (experiment 1) reduced C. Caryae infestation relative to non-treated control plots in both locations in 2014 and one of the two locations in 2015 (the other location had less than 1% infestation). In experiment 2, no differences among combined microbial treatments, single-applied microbial treatments or different numbers of application were observed, yet all microbial treatments reduced C. Caryae survival relative to the control. In the third experiment, both Grandevo and standard chemical insecticide applications resulted in lower weevil infestation than the control (both years) and there was no difference between the insecticide treatments in 2014 although the chemical insecticide regime had slightly lower infestation in 2015. These results provide evidence that microbial biopesticides can substantially reduce pecan weevil infestations in organic and nonorganic systems.
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An insect pupal cell with antimicrobial properties that suppress an entomopathogenic fungus.
Journal of invertebrate pathology, 2014Co-Authors: David I. Shapiro-ilan, Russell F. MizellAbstract:Abstract Soil-dwelling insects have developed various mechanisms to defend against pathogen infection. The pecan weevil, Curculio Caryae, spends two to three years in the soil inside an earthen cell. We hypothesized that the cell may possess antimicrobial properties. In a laboratory study, we tested the hypothesis using the fungus Beauveria bassiana as a model. B. bassiana is a common endemic pathogen of C. Caryae. We compared the number of colony-forming-units on selective media when B. bassiana was exposed to autoclaved soil, non-autoclaved soil, or soil from a C. Caryae pupal cell. Soil from C. Caryae cells was suppressive to B. bassiana. To our knowledge this is the first report of antimicrobial properties associated with an insect soil cell. The findings expand our knowledge of host–pathogen relationships. Additional research is needed to determine the basis for the suppressive effects observed.
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Effects of Entomopathogenic Fungus Species, and Impact of Fertilizers, on Biological Control of Pecan Weevil (Coleoptera: Curculionidae)
Environmental entomology, 2013Co-Authors: David I. Shapiro-ilan, Wayne A Gardner, Ted E. Cottrell, Robert W. Behle, Lenny Wells, Bruce W. WoodAbstract:ABSTRACT The pecan weevil, Curculio Caryae (Horn), is a key pest of pecan, Carya illinoinensis (Wangenh.) K. Koch. Prior research indicated the potential for use of Hypocreales fungi to suppress C. Caryae. We compared the efficacy of two fungal spp., Beauveria bassiana (GHA strain) and Metarhizium brunneum (F52), in their ability to cause C. Caryae mortality. The fungus, B. bassiana, was applied to trunks of pecan trees (a method previously shown to be effective in C. Caryae suppression) and efficacy was compared with M. brunneum applied to the ground or to the trunk with or without SoyScreen Oil as an ultraviolet protecting agent. Results indicated B. bassiana to be superior to M. brunneum regardless of application method; consequently, the potential for applying B. bassiana to control C. Caryae was explored further. Specifically, the impact of different fertilizer regimes (as used by pecan growers) on the persistence of B. bassiana (GHA) in soil was determined. B. bassiana was applied to soil in a pecan...
Bruce W. Wood - One of the best experts on this subject based on the ideXlab platform.
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Effects of Entomopathogenic Fungus Species, and Impact of Fertilizers, on Biological Control of Pecan Weevil (Coleoptera: Curculionidae)
Environmental entomology, 2013Co-Authors: David I. Shapiro-ilan, Wayne A Gardner, Ted E. Cottrell, Robert W. Behle, Lenny Wells, Bruce W. WoodAbstract:ABSTRACT The pecan weevil, Curculio Caryae (Horn), is a key pest of pecan, Carya illinoinensis (Wangenh.) K. Koch. Prior research indicated the potential for use of Hypocreales fungi to suppress C. Caryae. We compared the efficacy of two fungal spp., Beauveria bassiana (GHA strain) and Metarhizium brunneum (F52), in their ability to cause C. Caryae mortality. The fungus, B. bassiana, was applied to trunks of pecan trees (a method previously shown to be effective in C. Caryae suppression) and efficacy was compared with M. brunneum applied to the ground or to the trunk with or without SoyScreen Oil as an ultraviolet protecting agent. Results indicated B. bassiana to be superior to M. brunneum regardless of application method; consequently, the potential for applying B. bassiana to control C. Caryae was explored further. Specifically, the impact of different fertilizer regimes (as used by pecan growers) on the persistence of B. bassiana (GHA) in soil was determined. B. bassiana was applied to soil in a pecan...
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Control of Key Pecan Insect Pests using Biorational Pesticides
Journal of economic entomology, 2013Co-Authors: David I. Shapiro-ilan, Ted E. Cottrell, Mark A. Jackson, Bruce W. WoodAbstract:Key pecan insect pests include the black pecan aphid, Melanocallis Caryaefoliae (Davis), pecan weevil, Curculio Caryae (Horn), and stink bugs (Hemiptera: Pentatomidae). Alternative control tactics are needed for management of these pests in organic and conventional systems. Our objective was to evaluate the potential utility of several alternative insecticides including three plant extract formulations, eucalyptus extract, citrus extract-8.92%, and citrus extract-19.4%, and two microbial insecticides, Chromobacterium subtsugae (Martin et al.) and Isaria fumosorosea (Wize). In the laboratory, eucalyptus extract, citrus extract-8.92%, citrus extract-19.4%, and C. subtsugae caused M. Caryaefoliae mortality (mortality was reached approximately 78, 83, and 96%, respectively). In field tests, combined applications of I. fumosorosea with eucalyptus extract were synergistic and caused up to 82% mortality in M. Caryaefoliae. In laboratory assays focusing on C. Caryae suppression, C. subtsugae reduced feeding and oviposition damage, eucalyptus extract and citrus extract-19.4% were ineffective, and antagonism was observed when citrus extract-19.4% was combined with the entomopathogenic nematode, Steinernema carpocapsae (Weiser). In field tests, C. subtsugae reduced C. Caryae damage by 55% within the first 3d, and caused 74.5% corrected mortality within 7 d posttreatment. In the laboratory, C. subtsugae and eucalyptus extract did not cause mortality in the brown stink bug, Euschistus servus (Say). Applications of C. subtsugae for suppression of C. Caryae, and eucalyptus extract plus I. fumosorosea for control of M. Caryaefoliae show promise as alternative insecticides and should be evaluated further.
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Cumulative Impact of a Clover Cover Crop on the Persistence and Efficacy of Beauveria bassiana in Suppressing the Pecan Weevil (Coleoptera: Curculionidae)
Environmental entomology, 2012Co-Authors: David I. Shapiro-ilan, Wayne A Gardner, Lenny Wells, Bruce W. WoodAbstract:ABSTRACT The pecan weevil, Curculio Caryae (Horn), is a key pest of pecan. Endemic levels of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin can occur in pecan orchards and contribute to natural control of C. Caryae. Commercial formulations of the fungus can also be applied for suppression of C. Caryae. We hypothesized that a clover cover crop enhances B. bassiana efficacy and persistence (e.g., by protecting the fungus against abiotic environmental stresses). The hypothesis was tested by conducting field trials in a pecan orchard in Byron, GA, in 2009 and 2010. The study included four treatments arranged in a factorial with two levels of fungus (endemic fungus only, and application of a commercial B. bassiana product), and two levels of clover (white clover, Trifolium repens L., and no clover). Fungal persistence was measured by determining the number of CFUs per gram of soil over time (during 42 d postapplication of B. bassiana in 2009 and 29 d in 2010). Efficacy was measured by captu...
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Effects of combining microbial and chemical insecticides on mortality of the Pecan Weevil (Coleoptera: Curculionidae)
Journal of economic entomology, 2011Co-Authors: David I. Shapiro-ilan, Ted E. Cottrell, Bruce W. WoodAbstract:The pecan weevil, Curculio Caryae (Horn), is a key pest of pecan [Carya illinoinensis (Wangenh.) K. Koch]. Current control recommendations are based on chemical insecticide applications. Microbial control agents such as the entomopathogenic nematode, Steinernema carpocapsae (Weiser) and the fungus Beauveria bassiana (Balsamo) Vuillemin occur naturally in southeastern U.S. pecan orchards and have shown promise as alternative control agents for C. caryjae. Conceivably, the chemical and microbial agents occur simultaneously within pecan orchards or might be applied concurrently. The objective of this study was to determine the interactions between two chemical insecticides that are used in commercial C. Caryae control (i.e., carbaryl and cypermethrin applied below field rates) and the microbial agents B. bassiana and S. carpocapsae. In laboratory experiments, pecan weevil larval or adult mortality was assessed after application of microbial or chemical treatments applied singly or in combination (microbial + chemical agent). The nature of interactions (antagonism, additivity, or synergy) in terms of weevil mortality was evaluated over 9 d (larvae) or 5 d (adults). Results for B. bassiana indicated synergistic activity with carbaryl and antagonism with cypermethrin in C. Caryae larvae and adults. For S. carpocapsae, synergy was detected with both chemicals in C. Caryae larvae, but only additive effects were detected in adult weevils. Our results indicate that the chemical-microbial combinations tested are compatible with the exception of B. bassiana and cypermethrin. In addition, combinations that exhibited synergistic interactions may provide enhanced C. Caryae control in commercial field applications; thus, their potential merits further exploration.
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Comparison of application methods for suppressing the pecan weevil (Coleoptera: Curculionidae) with Beauveria bassiana under field conditions.
Environmental entomology, 2008Co-Authors: David I. Shapiro-ilan, Wayne A Gardner, Ted E. Cottrell, Robert W. Behle, Bruce W. WoodAbstract:The pecan weevil, Curculio Caryae (Horn), is a key pest of pecans. The entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin is pathogenic to C. Caryae. One approach to managing C. Caryae may be application of B. bassiana directed toward adult weevils as they emerge from the soil to attack nuts in the tree canopy. Our objective was to compare different application methods for suppression of C. Caryae adults. Treatments included direct application of B. bassiana (GHA strain) to soil under the tree canopy, soil application followed by cultivation, soil application in conjunction with a cover crop (Sudan grass), direct application to the tree trunk, and application to the trunk with an UV radiation-protecting adjuvant. The study was conducted in a pecan orchard in Byron, GA, in 2005 and 2006. Naturally emerging C. Caryae adults, caught after crawling to the trunk, were transported to the laboratory to determine percentage mortality and signs of mycosis. When averaged over the 15-d sampling period, weevil mortality and signs of mycosis were greater in all treatments than in the nontreated control in 2005 and 2006; >75% average mortality was observed with the trunk application both years and in the trunk application with UV protection in 2005. Results indicated trunk applications can produce superior efficacy relative to ground application, particularly if the ground application is followed by cultivation. Efficacy in the cover crop treatment, however, did not differ from other application approaches. Future research should focus on elucidating the causes for treatment differences we observed and the extent to which B. bassiana-induced C. Caryae mortality reduces crop damage.
Wayne A Gardner - One of the best experts on this subject based on the ideXlab platform.
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Effects of Entomopathogenic Fungus Species, and Impact of Fertilizers, on Biological Control of Pecan Weevil (Coleoptera: Curculionidae)
Environmental entomology, 2013Co-Authors: David I. Shapiro-ilan, Wayne A Gardner, Ted E. Cottrell, Robert W. Behle, Lenny Wells, Bruce W. WoodAbstract:ABSTRACT The pecan weevil, Curculio Caryae (Horn), is a key pest of pecan, Carya illinoinensis (Wangenh.) K. Koch. Prior research indicated the potential for use of Hypocreales fungi to suppress C. Caryae. We compared the efficacy of two fungal spp., Beauveria bassiana (GHA strain) and Metarhizium brunneum (F52), in their ability to cause C. Caryae mortality. The fungus, B. bassiana, was applied to trunks of pecan trees (a method previously shown to be effective in C. Caryae suppression) and efficacy was compared with M. brunneum applied to the ground or to the trunk with or without SoyScreen Oil as an ultraviolet protecting agent. Results indicated B. bassiana to be superior to M. brunneum regardless of application method; consequently, the potential for applying B. bassiana to control C. Caryae was explored further. Specifically, the impact of different fertilizer regimes (as used by pecan growers) on the persistence of B. bassiana (GHA) in soil was determined. B. bassiana was applied to soil in a pecan...
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Cumulative Impact of a Clover Cover Crop on the Persistence and Efficacy of Beauveria bassiana in Suppressing the Pecan Weevil (Coleoptera: Curculionidae)
Environmental entomology, 2012Co-Authors: David I. Shapiro-ilan, Wayne A Gardner, Lenny Wells, Bruce W. WoodAbstract:ABSTRACT The pecan weevil, Curculio Caryae (Horn), is a key pest of pecan. Endemic levels of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin can occur in pecan orchards and contribute to natural control of C. Caryae. Commercial formulations of the fungus can also be applied for suppression of C. Caryae. We hypothesized that a clover cover crop enhances B. bassiana efficacy and persistence (e.g., by protecting the fungus against abiotic environmental stresses). The hypothesis was tested by conducting field trials in a pecan orchard in Byron, GA, in 2009 and 2010. The study included four treatments arranged in a factorial with two levels of fungus (endemic fungus only, and application of a commercial B. bassiana product), and two levels of clover (white clover, Trifolium repens L., and no clover). Fungal persistence was measured by determining the number of CFUs per gram of soil over time (during 42 d postapplication of B. bassiana in 2009 and 29 d in 2010). Efficacy was measured by captu...
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Improved Control of Curculio Caryae (Coleoptera: Curculionidae) through Multi-Stage Pre-Emergence Applications of Steinernema carpocapsae
Journal of Entomological Science, 2012Co-Authors: David I. Shapiro-ilan, Wayne A GardnerAbstract:Abstract The pecan weevil, Curculio Caryae (Horn), is a key pest of pecan in North America. Entomopathogenic nematodes have potential as alternative control agents for C. Caryae. In prior studies, when single applications of entomopathogenic nematodes were applied during adult weevil emergence, only moderate efficacy was observed. The objective of this study was to determine the compounded impact of multistage nematode applications on C. Caryae mortality over a 2-year period. Experiments were conducted in a pecan orchard in Byron, GA. In the fall of 2007, freshly-emerged C. Caryae larvae were placed in pots under the tree canopy. The nematode, Steinernema carpocapsae (Weiser), was applied 3 times in spring through fall of 2008 (targeting C. Caryae larvae) and 3 times during the spring and summer of 2009 (primarily targeting adults). The percentage of surviving C. Caryae was determined in the fall of 2008 and 2009, approximately 1 and 2 years after larvae emerged. In 2008 (1 year postemergence), the number...
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Efficacy of Entomopathogenic Fungi in Suppressing Pecan Weevil, Curculio Caryae (Coleoptera: Curculionidae), in Commercial Pecan Orchards
Southwestern Entomologist, 2009Co-Authors: David I. Shapiro-ilan, Wayne A Gardner, Ted E. Cottrell, Bill Ree, Robert W. Behle, Marvin K. HarrisAbstract:Abstract. The pecan weevil, Curculio Caryae (Horn), is a key pest of pecans, Carya illinoinensis (Wangenh.) K. Koch. The entomopathogenic fungi Beauveria bassiana (Balsamo) Vuillemin and Metarhizium anisopliae (Metschnikoff) Sorokin are pathogenic to and are being developed as microbial control agents for pecan weevil. One approach to suppressing pest populations and the resultant damage might be to apply entomopathogenic fungi when adult pecan weevils are emerging from the soil. Here we report the efficacy of B. bassiana (GHA strain) and M. anisopliae (F52 strain) applied to trees in orchards at three locations: Byron, GA, Fort Valley, GA, and Comanche, TX. At Fort Valley, treatments included B. bassiana as an oil-based spray with a UV-protective screen applied to the trunk, M. anisopliae applied as an impregnated fiber band stapled onto the trunk, and a nontreated check. At Byron, GA, we compared the B. bassiana trunk treatment to a nontreated check. Treatments at the Texas location were the B. bassiana...
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Laboratory mortality and mycosis of adult Curculio Caryae (Coleoptera: Curculionidae) following application of Metarhizium anisopliae in the laboratory or field.
Journal of Entomological Science, 2009Co-Authors: David I. Shapiro-ilan, Wayne A Gardner, Ted E. Cottrell, Jarrod E. Leland, Robert W. BehleAbstract:The pecan weevil, Curculio Caryae (Horn), is a key pest of pecans. The entomopathogenic fungi Beauveria bassiana (Balsamo) Vuillemin and Metarhizium anisopliae (Metschnikoff) Sorokin are pathogenic to C. Caryae. One approach to suppressing this pest may be to apply entomopathogenic fungi to adult C. Caryae when they are emerging from the soil. However, thus far, laboratory screening of fungal isolates has been focused mostly on virulence to larval C. Caryae, and published field trials on adult control have focused on application of B. bassiana. Our objective was to determine the potential of M. anisopliae to control emerging C. Caryae adults. First, a laboratory test was conducted to compare 4 B. bassiana strains (Bb GA2, BbLA3, BbMS1, and GHA)and3/W. anisopliae strains (F52, MaLA4, and MaLA7) for virulence to C. Caryae adults. Virulence of the M. anisopliae strains was equal or greater than B. bassiana strains. Subsequently, a commercially available M. anisopliae strain (F52) was tested under field conditions when applied as a narrow fiber band that was impregnated with fungus and wrapped around the tree trunk, and/or when applied directly to the soil. In 2005, we applied M. anisopliae as trunk bands with or without additional application to the soil in the same plots. In 2006, we applied trunk bands or soil applications in separate plots. For 15 d posttreatment, weevils were trapped and transported to the laboratory to record mortality and mycosis. In 2005, weevil emergence was extremely low and statistical analysis was only feasible 3d posttreatment (at which time no treatment differences were detected), and 15 d posttreatment, at which time higher mortality and mycosis was observed in both the trunk band application and the trunk band + ground treatment compared with a nontreated control (and no difference between the two fungal treatments was detected). In 2006 overall average C. Caryae mycosis was higher in trunk band and ground treatment compared with an untreated control, whereas average total mortality (from the fungus or other causes) was not different among treatments except at 8 d post treatment (in which only the band treatment was significantly greater than the control). It must be noted that our evaluation of efficacy was only an estimation of potential insect control (as opposed to actual field suppression of C. Caryae) because our analysis was based on C. Caryae mortality following transport to controlled environmental conditions. Nonetheless, our research indicates that trunk band or ground applications of M. anisopliae may have potential to cause significant infection in C. Caryae populations.
Ted E. Cottrell - One of the best experts on this subject based on the ideXlab platform.
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Efficacy of Sulfuryl Fluoride Against Fourth-Instar Pecan Weevil (Coleoptera: Curculionidae) in Pecans for Quarantine Security.
Journal of economic entomology, 2020Co-Authors: Ted E. Cottrell, Michael J. Aikins, Ellen M. Thoms, Thomas W. PhillipsAbstract:The efficacy of sulfuryl fluoride was evaluated for control of fourth-instar pecan weevil, Curculio Caryae (Horn), at 25°C for a 24-h exposure. Larvae, collected as they naturally emerged from pecans, were used to artificially infest pecan nuts. Infested nuts were fumigated with six concentration by time (CT) treatment dosages of sulfuryl fluoride (0–750 g-h/m3) within air-tight, glass containers. The sulfuryl fluoride concentration in each fumigation container was analyzed 30 min after sulfuryl fluoride introduction and just prior to termination of the experiment. Mean sulfuryl fluoride CT dosages were calculated from sulfuryl fluoride measurements and were used for probit analysis. The lethal accumulated dosage (LAD99) of sulfuryl fluoride for pecan weevil was 1052.0 g-h/m3 with a 95% C.I. of 683.21–2,573.0 g-h/m3. For the confirmatory trial, we used two sulfuryl fluoride CT dosage treatments, 1,100 and 1,300 g-h/m3, and a nonfumigated control. All larvae were dead in both fumigation treatments by 14-d postfumigation. Due to higher mortality in the nonfumigated control in the confirmatory trial compared to that of the dose–response trial, 1300 g-h/m3 was selected as the sulfuryl fluoride CT dosage for a proposed quarantine treatment schedule. Fumigating pecans with sulfuryl fluoride can control larval pecan weevil infestations in commercially traded nuts and maintain compliance with quarantine regulations both within and outside the United States.
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Control of Pecan Weevil With Microbial Biopesticides.
Environmental entomology, 2017Co-Authors: David I. Shapiro-ilan, Ted E. Cottrell, Lenny Wells, Clive H. Bock, Kim Mai, Debbie Boykin, William G. Hudson, Russell F. MizellAbstract:The pecan weevil, Curculio Caryae (Horn) (Coleoptera: Curculionidae), is a key pest of pecans Carya illinoinensis ([Wangenh.] K. Koch) (Fagales: Juglandaceae). Control recommendations rely on broad spectrum chemical insecticides. Due to regulatory and environmental concerns, effective alternatives for C. Caryae control must be sought for pecan production in conventional and organic systems. We explored the use of microbial biopesticides for control of C. Caryae in Georgia pecan orchards. Three experiments were conducted. The first investigated an integrated microbial control approach in an organic system at two locations. Three microbial agents, Grandevo (based on byproducts of the bacterium Chromobacterium subtsugae Martin, Gundersen-Rindal, Blackburn & Buyer), the entomopathogenic nematode Steinernema carpocapsae (Weiser), and entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin, were applied to each treatment plot (0.6 ha) at different times during the season. A second experiment compared the effects of S. carpocapsae and B. bassiana applied as single treatments relative to application of both agents (at different times); survival of C. Caryae was assessed approximately 11 mo after larvae were added to pots sunk in an organic pecan orchard. In a conventional orchard (with 1.0 ha plots), the third experiment compared Grandevo applications to a commonly used regime of chemical insecticides (carbaryl alternated with a pyrethroid). All experiments were repeated in consecutive years. The combined pest management tactic (experiment 1) reduced C. Caryae infestation relative to non-treated control plots in both locations in 2014 and one of the two locations in 2015 (the other location had less than 1% infestation). In experiment 2, no differences among combined microbial treatments, single-applied microbial treatments or different numbers of application were observed, yet all microbial treatments reduced C. Caryae survival relative to the control. In the third experiment, both Grandevo and standard chemical insecticide applications resulted in lower weevil infestation than the control (both years) and there was no difference between the insecticide treatments in 2014 although the chemical insecticide regime had slightly lower infestation in 2015. These results provide evidence that microbial biopesticides can substantially reduce pecan weevil infestations in organic and nonorganic systems.
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Effects of Entomopathogenic Fungus Species, and Impact of Fertilizers, on Biological Control of Pecan Weevil (Coleoptera: Curculionidae)
Environmental entomology, 2013Co-Authors: David I. Shapiro-ilan, Wayne A Gardner, Ted E. Cottrell, Robert W. Behle, Lenny Wells, Bruce W. WoodAbstract:ABSTRACT The pecan weevil, Curculio Caryae (Horn), is a key pest of pecan, Carya illinoinensis (Wangenh.) K. Koch. Prior research indicated the potential for use of Hypocreales fungi to suppress C. Caryae. We compared the efficacy of two fungal spp., Beauveria bassiana (GHA strain) and Metarhizium brunneum (F52), in their ability to cause C. Caryae mortality. The fungus, B. bassiana, was applied to trunks of pecan trees (a method previously shown to be effective in C. Caryae suppression) and efficacy was compared with M. brunneum applied to the ground or to the trunk with or without SoyScreen Oil as an ultraviolet protecting agent. Results indicated B. bassiana to be superior to M. brunneum regardless of application method; consequently, the potential for applying B. bassiana to control C. Caryae was explored further. Specifically, the impact of different fertilizer regimes (as used by pecan growers) on the persistence of B. bassiana (GHA) in soil was determined. B. bassiana was applied to soil in a pecan...
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Control of Key Pecan Insect Pests using Biorational Pesticides
Journal of economic entomology, 2013Co-Authors: David I. Shapiro-ilan, Ted E. Cottrell, Mark A. Jackson, Bruce W. WoodAbstract:Key pecan insect pests include the black pecan aphid, Melanocallis Caryaefoliae (Davis), pecan weevil, Curculio Caryae (Horn), and stink bugs (Hemiptera: Pentatomidae). Alternative control tactics are needed for management of these pests in organic and conventional systems. Our objective was to evaluate the potential utility of several alternative insecticides including three plant extract formulations, eucalyptus extract, citrus extract-8.92%, and citrus extract-19.4%, and two microbial insecticides, Chromobacterium subtsugae (Martin et al.) and Isaria fumosorosea (Wize). In the laboratory, eucalyptus extract, citrus extract-8.92%, citrus extract-19.4%, and C. subtsugae caused M. Caryaefoliae mortality (mortality was reached approximately 78, 83, and 96%, respectively). In field tests, combined applications of I. fumosorosea with eucalyptus extract were synergistic and caused up to 82% mortality in M. Caryaefoliae. In laboratory assays focusing on C. Caryae suppression, C. subtsugae reduced feeding and oviposition damage, eucalyptus extract and citrus extract-19.4% were ineffective, and antagonism was observed when citrus extract-19.4% was combined with the entomopathogenic nematode, Steinernema carpocapsae (Weiser). In field tests, C. subtsugae reduced C. Caryae damage by 55% within the first 3d, and caused 74.5% corrected mortality within 7 d posttreatment. In the laboratory, C. subtsugae and eucalyptus extract did not cause mortality in the brown stink bug, Euschistus servus (Say). Applications of C. subtsugae for suppression of C. Caryae, and eucalyptus extract plus I. fumosorosea for control of M. Caryaefoliae show promise as alternative insecticides and should be evaluated further.
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Effects of combining microbial and chemical insecticides on mortality of the Pecan Weevil (Coleoptera: Curculionidae)
Journal of economic entomology, 2011Co-Authors: David I. Shapiro-ilan, Ted E. Cottrell, Bruce W. WoodAbstract:The pecan weevil, Curculio Caryae (Horn), is a key pest of pecan [Carya illinoinensis (Wangenh.) K. Koch]. Current control recommendations are based on chemical insecticide applications. Microbial control agents such as the entomopathogenic nematode, Steinernema carpocapsae (Weiser) and the fungus Beauveria bassiana (Balsamo) Vuillemin occur naturally in southeastern U.S. pecan orchards and have shown promise as alternative control agents for C. caryjae. Conceivably, the chemical and microbial agents occur simultaneously within pecan orchards or might be applied concurrently. The objective of this study was to determine the interactions between two chemical insecticides that are used in commercial C. Caryae control (i.e., carbaryl and cypermethrin applied below field rates) and the microbial agents B. bassiana and S. carpocapsae. In laboratory experiments, pecan weevil larval or adult mortality was assessed after application of microbial or chemical treatments applied singly or in combination (microbial + chemical agent). The nature of interactions (antagonism, additivity, or synergy) in terms of weevil mortality was evaluated over 9 d (larvae) or 5 d (adults). Results for B. bassiana indicated synergistic activity with carbaryl and antagonism with cypermethrin in C. Caryae larvae and adults. For S. carpocapsae, synergy was detected with both chemicals in C. Caryae larvae, but only additive effects were detected in adult weevils. Our results indicate that the chemical-microbial combinations tested are compatible with the exception of B. bassiana and cypermethrin. In addition, combinations that exhibited synergistic interactions may provide enhanced C. Caryae control in commercial field applications; thus, their potential merits further exploration.
Marvin K. Harris - One of the best experts on this subject based on the ideXlab platform.
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Biology and Management of the Pecan Weevil (Coleoptera: Curculionidae)
Journal of Integrated Pest Management, 2012Co-Authors: Phillip G. Mulder, Marvin K. Harris, Richard A. GranthamAbstract:The pecan weevil, Curculio Caryae (Horn), and its primary host, pecan, Carya illinoinensis (Wagenheim) K. Koch are indigenous to North America east of the Rocky Mountains. This review is presented to describe the biology, life stages, crop injury, monitoring approaches, and primary control strategies currently used for pecan weevil in pecan. Suggested economic thresholds are extrapolated from several sources and the utility of current monitoring information is presented to aid in management and quarantine decisions.
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DNA identification confirms pecan weevil (Coleoptera: Curculionidae) infestation of Carpathian walnut.
Journal of economic entomology, 2010Co-Authors: Marvin K. Harris, Kenneth Hunt, Anthony I. CognatoAbstract:Larvae found infesting fruit from a Carpathian walnut, Juglans regia L., tree in Missouri were confirmed by DNA analysis to be those of pecan weevil, Curculio Caryae (Horn) (Coleoptera: Curculionidae). The infested walnut tree occurs in the midst of pecan weevil-infested pecans, Carya illinoinensis (Wang.) K. Koch; the larval haplotypes were found to be identical to pecan weevil larvae from the region, indicating that the walnut infestation arose by association with infested pecan. This is the first confirmed DNA analysis showing pecan weevil attacks J. regia and the second report that J. regia may be at risk of infestation by pecan weevil. Further study indicates this infestation on walnut is established and ongoing. The pecan weevil is a key pest of pecan and seems capable of inflicting similar damage to walnut if spread to commercial areas that produce J. regia.
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Efficacy of Entomopathogenic Fungi in Suppressing Pecan Weevil, Curculio Caryae (Coleoptera: Curculionidae), in Commercial Pecan Orchards
Southwestern Entomologist, 2009Co-Authors: David I. Shapiro-ilan, Wayne A Gardner, Ted E. Cottrell, Bill Ree, Robert W. Behle, Marvin K. HarrisAbstract:Abstract. The pecan weevil, Curculio Caryae (Horn), is a key pest of pecans, Carya illinoinensis (Wangenh.) K. Koch. The entomopathogenic fungi Beauveria bassiana (Balsamo) Vuillemin and Metarhizium anisopliae (Metschnikoff) Sorokin are pathogenic to and are being developed as microbial control agents for pecan weevil. One approach to suppressing pest populations and the resultant damage might be to apply entomopathogenic fungi when adult pecan weevils are emerging from the soil. Here we report the efficacy of B. bassiana (GHA strain) and M. anisopliae (F52 strain) applied to trees in orchards at three locations: Byron, GA, Fort Valley, GA, and Comanche, TX. At Fort Valley, treatments included B. bassiana as an oil-based spray with a UV-protective screen applied to the trunk, M. anisopliae applied as an impregnated fiber band stapled onto the trunk, and a nontreated check. At Byron, GA, we compared the B. bassiana trunk treatment to a nontreated check. Treatments at the Texas location were the B. bassiana...
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Population Genetics of the Pecan Weevil (Coleoptera: Curculionidae) Inferred from Mitochondrial Nucleotide Data
Annals of the Entomological Society of America, 2007Co-Authors: Glené Mynhardt, Marvin K. Harris, Anthony I. CognatoAbstract:The pecan weevil, Curculio Caryae (Horn) (Coleoptera: Curculionidae), is an obligate nut feeder of all hickory (Carya spp.) and a key pest of the pecan, Carya illinoinensis Koch. This study investigates population genetic structure of the pecan weevil. Gene sow and genetic variation was estimated for 90 pecan weevil specimens sampled within the range Carya occurring in the United States. Cladistic and nested clade analyses, as well as an analysis of molecular variance of mitochondrial DNA cytochrome oxidase I were performed. Six-hundred and forty equally parsimonious trees of 31 haplotypes demonstrated high genetic diversity across all pecan weevil samples, and signiÞcant regional subdivision. Three clades recovered in the parsimony and nested clade analyses were strongly associated with western, central, and eastern localities sampled within the range of C. Caryae. The current distribution of C. Caryae and population structure were explained by past glaciation events. The data indicate C. Caryae diverged from its sister species, Curculio nasicus (Say), 4.3 million years before present (mybp). Lineage divergence between the western and eastern populations occurred during the Pleistocene (1.1 million mybp), and a more recent divergence occurred between C. Caryae populations east and west of the Appalachian mountain range (870,000 yr ago). Haplotypes were segregated by region, but further sampling is necessary to test for gene sow among these regions.
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Controlling the Pecan Weevil
2005Co-Authors: Bill Ree, Allen E. Knutson, Marvin K. HarrisAbstract:*Extension Agent-IPM(Pecans), Extension Entomologist and Entomology Professor, The Texas A&M University System. Figure 1. Pecan weevils are found in 131 counties in Texas. The pecan weevil (Curculio Caryae [Horn]) is a key pest of pecan in the United States and portions of Texas. Pecan weevils, which also feed on all species of North American hickory, can be found from New York to Iowa, south to Oklahoma, and across the southeastern states from Florida to west Texas. As of 1999, pecan weevil had been found in 131 Texas counties (Fig. 1).
