Numerous studies have demonstrated induction of proteins in plant tissues by wounding and infesta... more Numerous studies have demonstrated induction of proteins in plant tissues by wounding and infestations by various pests and pathogens. Lipoxygenase (LOX) is among the proteins that has been found to be induced by pathogens, but detailed information on the induction of LOX has not been reported. We have found a large (up to 10-fold) increase in LOX activity upon wounding of soybean (Glycine max L. Merr.) leaves and variable increases due to feeding of the twospotted spider mite. This induction in LOX activity was reflected in increases in amounts of both LOX protein and transcripts suggesting that the induction was at the transcriptional level. LOX activity was also found to be increased in unwounded leaves from plants with wounded leaves lower on the stem indicating that translocatable factors can cause remote induction of LOX activity.
ABSTRACT The effect of methyl jasmonate treatment of 2 plant species (cabbage and tobacco) on the... more ABSTRACT The effect of methyl jasmonate treatment of 2 plant species (cabbage and tobacco) on the feeding of their corresponding lepidopteran pests was studied. Treatment of cabbage and tobacco plants with methyl jasmonate increased lipoxygenase activity in the leaf tissues. Reduced feeding of lepidopteran larvae was observed in choice test experiments with cabbage loopers and tobacco hornworms. Similar results were obtained for the feeding of both pests on detached methyl jasmonate-treated leaves. Treatment of tobacco plants with methyl jasmonate had no effect on hatching of hornworm eggs but inhibited larval development after hatching. Application of methyl jasmonate to detached leaves in petri plates also inhibited feeding of tobacco hornworms. Methyl jasmonate is known to increase lipoxygenase activity in several plant species and cause elevated production of volatile C6-aldehydes. The same aldehydes that increased after treatment of plants with methyl jasmonate (hexanal and E-2-hexenal) inhibited feeding of tobacco hornworms on detached tobacco leaves. No effect was observed on larval development and pupation of either cabbage loopers or tobacco hornworms when methyl jasmonate was applied to artificial diet. Cabbage looper larvae whose feeding was inhibited on leaves from methyl jasmonate-treated plants were transferred to an artificial diet along with larvae that fed on the leaves from control plants. There was no effect observed on the subsequent development of either larval group. This study demonstrates that inhibition of lepidopteran larval feeding is not caused by the direct effect of methyl jasmonate, but rather to altered metabolism in the plant tissues.
Transovum transmission efficiencies of the multiply-embedded form of Au tographa californica nucl... more Transovum transmission efficiencies of the multiply-embedded form of Au tographa californica nucleopolyhedrosis virus (AcMNPV) and the singly-embedded form of Heliothis zea nucleopolyhedrosis virus (HzSNPV) were comparatively evaluated against the tobacco budworm, Heliothis virescens (F.) using an autodissemination technique. The corrected mean viral-induced mortality for progeny arising from mating pairs in which only the male was surface contaminated with virus was 68.8% for AcMNPV and 53.0% for HzSNPV. AcMNPV, however, induced an LT50 response approximately one day sooner than HzSNPV. Scanning electron microscopy (SEM) revealed that polyhedra were abundant on the chorion of eggs laid by females indirectly contaminated with virus. Although much variation occurred, all the eggs observed had some degree of viral contamination. Polyhedra were concentrated on the upper hemisphere of the eggs and along the ridge-like features of the chorion; particularly at the rosette where they would most likely be ingested during eclosi?n. SEM also revealed abundant polyhedra on the wing and body scales of adults. The size and shape of polyhedra conformed to the linear depressions of the scales. Naturally occurring nucleopolyhedrosis viruses (NPV), Baculovirus, Subgroup A (Wildy, 1971), have long been recognized as important factors in the eventual collapse of lepidopterous and hymenopterous pest populations (Burges, 1981; Granados and Federici, 1986; Smith, 1976). Consequently, these viruses have received much attention as microbial control agents (Allen et al., 1978; Burges, 1981; Granados and Federici, 1986; Smith, 1976). Most attempts to utilize these viruses in microbial control have deployed them as microbial insecticides although alternative deployment strategies, such as autodissemination, have been proposed (Allen et al., 1978). Autodissemination, as defined by Ignoffo (1978), is the pur poseful use of insects to spread an entomopathogen in the environment. This includes 1) the use of a stage or stages of the usual host that are refractive to the entomopathogen or 2) the use of unusual or non-host insect species to disperse the entomopathogens for subsequent encounter with susceptible hosts. As a first step toward developing a sex attractant-mediated form of autodis semination to facilitate dispersal of viruses infectious to the tobacco budworm, Heliothis virescens (TBW), we comparatively evaluated the transovum transmis 1 Scientific paper no. 89-7-166 of the Kentucky Agricultural Experiment Station, Lexington. This research has been conducted (in part) with funds from the USDA, ARS Cooperative Research Agree ment No. 58-43YK-8-0025. The contents do not necessarily reflect the views and policies of USDA, ARS. 2 Professor and Associate Professor, respectively, Department of Entomology, University of Ken tucky, Lexington, Kentucky 40546. 3 Research Entomologist, USDA, ARS, Crops Research Laboratory, Oxford, North Carolina 27565. Accepted for publication 23 October 1989. This content downloaded from 157.55.39.45 on Tue, 19 Jul 2016 05:40:08 UTC All use subject to http://about.jstor.org/terms 394 JOURNAL OF THE KANSAS ENTOMOLOGICAL SOCIETY sion efficiencies ofAutographa calif or nica multiply-embedded nucleopolyhedrosis virus (AcMNPV) and the Heliothis zea singly-embedded nucleopolyhedrosis virus (H3SNPV) derived from Elcar?. The objective of this study was to investigate opportunities for initiating early instar Baculovirus-induced mortality with viral dust formulations under controlled laboratory conditions with the longterm ob jective of utilizing the mating and oviposition behavior of the TBW to initiate early mortality among F, progeny in the field. The following information on transmission of these baculoviruses to progeny resulting from surface-contami nated adults represents some of our early laboratory research toward evaluating this strategy. Materials and Methods We initiated pair mating studies in the laboratory to determine transovum transmission efficiency under controlled conditions. Inocula used were a plaque purified AcMNPV isolate obtained as a gift from Dr. Edward M. Dougherty (USDA, ARS, Beltsville, MD) and HzSNPV derived from Elcar? sample obtained from Sandoz, Inc., San Diego, CA. Both viruses were increased by passage through a disease-free colony of tobacco budworm (TBW) maintained in the Insect Pa thology Laboratory, Department of Entomology, University of Kentucky. Newly molted fourth-instar TBW were individually inoculated per os by dispensing 2 ?xl of a suspension containing 7.0 x 103 PIB's of either virus onto the surface of 5mm diet discs in 24-well tissue culture dishes (Boucias and Nordin, 1977). Harvested virus was purified by differential centrifugation, washed in acetone, air-dried, then ground into a dust using a mortar and pestle. Polyhedra were then mixed 1:1 wt/wt with Day Glo? A-14-N Fire Orange fluorescent dye (2.8 x 1011 PIBVgram) to allow visualization of moth coverage. An…
... Rev. Roum. BioI. Ser. Bot. 2: 125-134. Millstein, J. A., GC Brown, and G. L. Nordin. 1982. Mi... more ... Rev. Roum. BioI. Ser. Bot. 2: 125-134. Millstein, J. A., GC Brown, and G. L. Nordin. 1982. Microclimatic humidity influence on conidial discharge in Erynia sp. ... 815. The Commonwealth MycologicalInstitute, Kew,Sur-rey, England. Wilding, N. and JN Perry 1980. ...
... such tritrophic interaction with which we have been working involves tobacco, Nicotiana ta-ba... more ... such tritrophic interaction with which we have been working involves tobacco, Nicotiana ta-bacum (L.), tIle tobacco aphid, Myzus nicotianae (Blackman), and the entomophthoralean fungus,Pandora neoaphidis (Remaudiere ... Glass coverslips were lined with a bead (2 mm ...
In the United States, the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), are oft... more In the United States, the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), are often tended by the aphid-tending ant, Lasius neoniger Emery (Hymenoptera: Formicidae). In this study, we examined the effects of tending by ants on the density and biomass of soybean aphids on soybeans in Kentucky. We performed cage studies that limited access by ants and/or natural enemies. We used a split-plot design with natural enemy access as the main plot and ant attendance as the sub plot. We found that natural enemy access negatively affected aphid population density in the presence of tending ants, seen as a three- to four-fold increase in aphid density when natural enemies were excluded. In addition, we found that ant tending positively affected aphid biomass, both when natural enemies were given access to aphids or when natural enemies were excluded, seen by a two-fold increase in aphid biomass when ants tended aphids, both in the presence or absence of natural enemies. Biomass accumulation is seen as an important measurement for assessing aphid performance, and we argue that aphid-tending by ants can have an influence on natural field populations of soybean aphids. Agronomic practices that affect ant abundance in soybeans may influence the performance and hence pest outbreaks for this economically important pest.
Data are presented which show that first brood codling moth larvae have a higher diapause rate (a... more Data are presented which show that first brood codling moth larvae have a higher diapause rate (and are thus univoltine) if reared in apples crowded with other larvae than if they are reared in uncrowded apples. From this relationship, a theoretical mechanism is proposed to help explain the interaction of genetic and nutritional effects in determining the dominant voltinism strain in codling moth populations.
A system of integro-differential equations is derived to describe epizootics of a fungal pathogen... more A system of integro-differential equations is derived to describe epizootics of a fungal pathogen in an insect population. Because of piecewise continuous behavior under some parametric conditions, it is concluded that standard phase orbits can be misleading. Using a different analytic approach yields a simple system of finite difference equations. Both the continuous and discrete versions are compared to classical forms. The continuous version differs from a classical one in possessing a second derivative dependent on population density. The discrete version differs in maintaining positive, non-zero populations of both infectives and susceptibles in finite time.
Chikungunya virus (CHIKV) caused a large outbreak in Puerto Rico in 2014, followed by a Zika viru... more Chikungunya virus (CHIKV) caused a large outbreak in Puerto Rico in 2014, followed by a Zika virus (ZIKV) outbreak in 2016. Communities Organized for the Prevention of Arboviruses (COPA) is a cohort study in southern Puerto Rico, initiated in 2018 to measure arboviral disease risk and provide a platform to evaluate interventions. To identify risk factors for infection, we assessed prevalence of previous CHIKV infection and recent ZIKV and DENV infection in a cross-sectional study among COPA participants. Participants aged 1–50 years (y) were recruited from randomly selected households in study clusters. Each participant completed an interview and provided a blood specimen, which was tested by anti-CHIKV IgG ELISA assay and anti-ZIKV and anti-DENV IgM MAC-ELISA assays. We assessed individual, household, and community factors associated with a positive result for CHIKV or ZIKV after adjusting for confounders. During 2018–2019, 4,090 participants were enrolled; 61% were female and medi...
Arboviral diseases transmitted by Aedes species mosquitoes pose an increasing public health chall... more Arboviral diseases transmitted by Aedes species mosquitoes pose an increasing public health challenge in tropical regions. Wolbachia-mediated population suppression (Wolbachia suppression) is a vector control method used to reduce Aedes mosquito populations by introducing male mosquitoes infected with Wolbachia, a naturally occurring endosymbiotic bacterium. When Wolbachia-infected male mosquitoes mate with female wild mosquitoes, the resulting eggs will not hatch. Public support is vital to the successful implementation and sustainability of vector control interventions. Communities Organized to Prevent Arboviruses (COPA) is a cohort study to determine the incidence of arboviral disease in Ponce, Puerto Rico and evaluate vector control methods. Focus groups were conducted with residents of COPA communities to gather their opinion on vector control methods; during 2018–2019, adult COPA participants were interviewed regarding their views on Wolbachia suppression; and a follow-up ques...
Numerous studies have demonstrated induction of proteins in plant tissues by wounding and infesta... more Numerous studies have demonstrated induction of proteins in plant tissues by wounding and infestations by various pests and pathogens. Lipoxygenase (LOX) is among the proteins that has been found to be induced by pathogens, but detailed information on the induction of LOX has not been reported. We have found a large (up to 10-fold) increase in LOX activity upon wounding of soybean (Glycine max L. Merr.) leaves and variable increases due to feeding of the twospotted spider mite. This induction in LOX activity was reflected in increases in amounts of both LOX protein and transcripts suggesting that the induction was at the transcriptional level. LOX activity was also found to be increased in unwounded leaves from plants with wounded leaves lower on the stem indicating that translocatable factors can cause remote induction of LOX activity.
ABSTRACT The effect of methyl jasmonate treatment of 2 plant species (cabbage and tobacco) on the... more ABSTRACT The effect of methyl jasmonate treatment of 2 plant species (cabbage and tobacco) on the feeding of their corresponding lepidopteran pests was studied. Treatment of cabbage and tobacco plants with methyl jasmonate increased lipoxygenase activity in the leaf tissues. Reduced feeding of lepidopteran larvae was observed in choice test experiments with cabbage loopers and tobacco hornworms. Similar results were obtained for the feeding of both pests on detached methyl jasmonate-treated leaves. Treatment of tobacco plants with methyl jasmonate had no effect on hatching of hornworm eggs but inhibited larval development after hatching. Application of methyl jasmonate to detached leaves in petri plates also inhibited feeding of tobacco hornworms. Methyl jasmonate is known to increase lipoxygenase activity in several plant species and cause elevated production of volatile C6-aldehydes. The same aldehydes that increased after treatment of plants with methyl jasmonate (hexanal and E-2-hexenal) inhibited feeding of tobacco hornworms on detached tobacco leaves. No effect was observed on larval development and pupation of either cabbage loopers or tobacco hornworms when methyl jasmonate was applied to artificial diet. Cabbage looper larvae whose feeding was inhibited on leaves from methyl jasmonate-treated plants were transferred to an artificial diet along with larvae that fed on the leaves from control plants. There was no effect observed on the subsequent development of either larval group. This study demonstrates that inhibition of lepidopteran larval feeding is not caused by the direct effect of methyl jasmonate, but rather to altered metabolism in the plant tissues.
Transovum transmission efficiencies of the multiply-embedded form of Au tographa californica nucl... more Transovum transmission efficiencies of the multiply-embedded form of Au tographa californica nucleopolyhedrosis virus (AcMNPV) and the singly-embedded form of Heliothis zea nucleopolyhedrosis virus (HzSNPV) were comparatively evaluated against the tobacco budworm, Heliothis virescens (F.) using an autodissemination technique. The corrected mean viral-induced mortality for progeny arising from mating pairs in which only the male was surface contaminated with virus was 68.8% for AcMNPV and 53.0% for HzSNPV. AcMNPV, however, induced an LT50 response approximately one day sooner than HzSNPV. Scanning electron microscopy (SEM) revealed that polyhedra were abundant on the chorion of eggs laid by females indirectly contaminated with virus. Although much variation occurred, all the eggs observed had some degree of viral contamination. Polyhedra were concentrated on the upper hemisphere of the eggs and along the ridge-like features of the chorion; particularly at the rosette where they would most likely be ingested during eclosi?n. SEM also revealed abundant polyhedra on the wing and body scales of adults. The size and shape of polyhedra conformed to the linear depressions of the scales. Naturally occurring nucleopolyhedrosis viruses (NPV), Baculovirus, Subgroup A (Wildy, 1971), have long been recognized as important factors in the eventual collapse of lepidopterous and hymenopterous pest populations (Burges, 1981; Granados and Federici, 1986; Smith, 1976). Consequently, these viruses have received much attention as microbial control agents (Allen et al., 1978; Burges, 1981; Granados and Federici, 1986; Smith, 1976). Most attempts to utilize these viruses in microbial control have deployed them as microbial insecticides although alternative deployment strategies, such as autodissemination, have been proposed (Allen et al., 1978). Autodissemination, as defined by Ignoffo (1978), is the pur poseful use of insects to spread an entomopathogen in the environment. This includes 1) the use of a stage or stages of the usual host that are refractive to the entomopathogen or 2) the use of unusual or non-host insect species to disperse the entomopathogens for subsequent encounter with susceptible hosts. As a first step toward developing a sex attractant-mediated form of autodis semination to facilitate dispersal of viruses infectious to the tobacco budworm, Heliothis virescens (TBW), we comparatively evaluated the transovum transmis 1 Scientific paper no. 89-7-166 of the Kentucky Agricultural Experiment Station, Lexington. This research has been conducted (in part) with funds from the USDA, ARS Cooperative Research Agree ment No. 58-43YK-8-0025. The contents do not necessarily reflect the views and policies of USDA, ARS. 2 Professor and Associate Professor, respectively, Department of Entomology, University of Ken tucky, Lexington, Kentucky 40546. 3 Research Entomologist, USDA, ARS, Crops Research Laboratory, Oxford, North Carolina 27565. Accepted for publication 23 October 1989. This content downloaded from 157.55.39.45 on Tue, 19 Jul 2016 05:40:08 UTC All use subject to http://about.jstor.org/terms 394 JOURNAL OF THE KANSAS ENTOMOLOGICAL SOCIETY sion efficiencies ofAutographa calif or nica multiply-embedded nucleopolyhedrosis virus (AcMNPV) and the Heliothis zea singly-embedded nucleopolyhedrosis virus (H3SNPV) derived from Elcar?. The objective of this study was to investigate opportunities for initiating early instar Baculovirus-induced mortality with viral dust formulations under controlled laboratory conditions with the longterm ob jective of utilizing the mating and oviposition behavior of the TBW to initiate early mortality among F, progeny in the field. The following information on transmission of these baculoviruses to progeny resulting from surface-contami nated adults represents some of our early laboratory research toward evaluating this strategy. Materials and Methods We initiated pair mating studies in the laboratory to determine transovum transmission efficiency under controlled conditions. Inocula used were a plaque purified AcMNPV isolate obtained as a gift from Dr. Edward M. Dougherty (USDA, ARS, Beltsville, MD) and HzSNPV derived from Elcar? sample obtained from Sandoz, Inc., San Diego, CA. Both viruses were increased by passage through a disease-free colony of tobacco budworm (TBW) maintained in the Insect Pa thology Laboratory, Department of Entomology, University of Kentucky. Newly molted fourth-instar TBW were individually inoculated per os by dispensing 2 ?xl of a suspension containing 7.0 x 103 PIB's of either virus onto the surface of 5mm diet discs in 24-well tissue culture dishes (Boucias and Nordin, 1977). Harvested virus was purified by differential centrifugation, washed in acetone, air-dried, then ground into a dust using a mortar and pestle. Polyhedra were then mixed 1:1 wt/wt with Day Glo? A-14-N Fire Orange fluorescent dye (2.8 x 1011 PIBVgram) to allow visualization of moth coverage. An…
... Rev. Roum. BioI. Ser. Bot. 2: 125-134. Millstein, J. A., GC Brown, and G. L. Nordin. 1982. Mi... more ... Rev. Roum. BioI. Ser. Bot. 2: 125-134. Millstein, J. A., GC Brown, and G. L. Nordin. 1982. Microclimatic humidity influence on conidial discharge in Erynia sp. ... 815. The Commonwealth MycologicalInstitute, Kew,Sur-rey, England. Wilding, N. and JN Perry 1980. ...
... such tritrophic interaction with which we have been working involves tobacco, Nicotiana ta-ba... more ... such tritrophic interaction with which we have been working involves tobacco, Nicotiana ta-bacum (L.), tIle tobacco aphid, Myzus nicotianae (Blackman), and the entomophthoralean fungus,Pandora neoaphidis (Remaudiere ... Glass coverslips were lined with a bead (2 mm ...
In the United States, the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), are oft... more In the United States, the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), are often tended by the aphid-tending ant, Lasius neoniger Emery (Hymenoptera: Formicidae). In this study, we examined the effects of tending by ants on the density and biomass of soybean aphids on soybeans in Kentucky. We performed cage studies that limited access by ants and/or natural enemies. We used a split-plot design with natural enemy access as the main plot and ant attendance as the sub plot. We found that natural enemy access negatively affected aphid population density in the presence of tending ants, seen as a three- to four-fold increase in aphid density when natural enemies were excluded. In addition, we found that ant tending positively affected aphid biomass, both when natural enemies were given access to aphids or when natural enemies were excluded, seen by a two-fold increase in aphid biomass when ants tended aphids, both in the presence or absence of natural enemies. Biomass accumulation is seen as an important measurement for assessing aphid performance, and we argue that aphid-tending by ants can have an influence on natural field populations of soybean aphids. Agronomic practices that affect ant abundance in soybeans may influence the performance and hence pest outbreaks for this economically important pest.
Data are presented which show that first brood codling moth larvae have a higher diapause rate (a... more Data are presented which show that first brood codling moth larvae have a higher diapause rate (and are thus univoltine) if reared in apples crowded with other larvae than if they are reared in uncrowded apples. From this relationship, a theoretical mechanism is proposed to help explain the interaction of genetic and nutritional effects in determining the dominant voltinism strain in codling moth populations.
A system of integro-differential equations is derived to describe epizootics of a fungal pathogen... more A system of integro-differential equations is derived to describe epizootics of a fungal pathogen in an insect population. Because of piecewise continuous behavior under some parametric conditions, it is concluded that standard phase orbits can be misleading. Using a different analytic approach yields a simple system of finite difference equations. Both the continuous and discrete versions are compared to classical forms. The continuous version differs from a classical one in possessing a second derivative dependent on population density. The discrete version differs in maintaining positive, non-zero populations of both infectives and susceptibles in finite time.
Chikungunya virus (CHIKV) caused a large outbreak in Puerto Rico in 2014, followed by a Zika viru... more Chikungunya virus (CHIKV) caused a large outbreak in Puerto Rico in 2014, followed by a Zika virus (ZIKV) outbreak in 2016. Communities Organized for the Prevention of Arboviruses (COPA) is a cohort study in southern Puerto Rico, initiated in 2018 to measure arboviral disease risk and provide a platform to evaluate interventions. To identify risk factors for infection, we assessed prevalence of previous CHIKV infection and recent ZIKV and DENV infection in a cross-sectional study among COPA participants. Participants aged 1–50 years (y) were recruited from randomly selected households in study clusters. Each participant completed an interview and provided a blood specimen, which was tested by anti-CHIKV IgG ELISA assay and anti-ZIKV and anti-DENV IgM MAC-ELISA assays. We assessed individual, household, and community factors associated with a positive result for CHIKV or ZIKV after adjusting for confounders. During 2018–2019, 4,090 participants were enrolled; 61% were female and medi...
Arboviral diseases transmitted by Aedes species mosquitoes pose an increasing public health chall... more Arboviral diseases transmitted by Aedes species mosquitoes pose an increasing public health challenge in tropical regions. Wolbachia-mediated population suppression (Wolbachia suppression) is a vector control method used to reduce Aedes mosquito populations by introducing male mosquitoes infected with Wolbachia, a naturally occurring endosymbiotic bacterium. When Wolbachia-infected male mosquitoes mate with female wild mosquitoes, the resulting eggs will not hatch. Public support is vital to the successful implementation and sustainability of vector control interventions. Communities Organized to Prevent Arboviruses (COPA) is a cohort study to determine the incidence of arboviral disease in Ponce, Puerto Rico and evaluate vector control methods. Focus groups were conducted with residents of COPA communities to gather their opinion on vector control methods; during 2018–2019, adult COPA participants were interviewed regarding their views on Wolbachia suppression; and a follow-up ques...
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