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Effects Of Bt Plants On Non-Target Herbivores, Richard L. Hellmich, Jarrad R. Prasifka, Patricia L. Anderson Jun 2019

Effects Of Bt Plants On Non-Target Herbivores, Richard L. Hellmich, Jarrad R. Prasifka, Patricia L. Anderson

Richard L Hellmich

INTRODUCTION

Transgenic (genetically modified) crops producing insecticidal toxins derived from Bacillus thuringiensis (Bt) bacteria have been scrutinised by government agencies, scientists and the public for their potential to negatively impact non-target organisms in or surrounding agricultural habitats. While several crops have been engineered to express one or more Bt toxins, it is such com (= maize) varieties that have had commercial success. Many strains of Bt exist, each producing one or more toxic crystalline (Cry) proteins, but the deleterious effects of each toxin are usually confined to a few related species in a single order of insects. The species to which ...


The Interaction Of Two-Spotted Spider Mites, Tetranychus Urticae Koch, With Cry Protein Production And Predation By Amblyseius Andersoni (Chant) In Cry1ac/Cry2ab Cotton And Cry1f Maize, Yan-Yan Guo, Jun-Ce Tian, Wang-Peng Shi, Xue-Hui Dong, Jörg Romeis, Steven E. Naranjo, Richard L. Hellmich, Anthony M. Shelton Apr 2019

The Interaction Of Two-Spotted Spider Mites, Tetranychus Urticae Koch, With Cry Protein Production And Predation By Amblyseius Andersoni (Chant) In Cry1ac/Cry2ab Cotton And Cry1f Maize, Yan-Yan Guo, Jun-Ce Tian, Wang-Peng Shi, Xue-Hui Dong, Jörg Romeis, Steven E. Naranjo, Richard L. Hellmich, Anthony M. Shelton

Richard L Hellmich

Crops producing insecticidal crystal (Cry) proteins from the bacterium, Bacillus thuringiensis(Bt), are an important tool for managing lepidopteran pests on cotton and maize. However, the effects of these Bt crops on non-target organisms, especially natural enemies that provide biological control services, are required to be addressed in an environmental risk assessment. Amblyseius andersoni (Acari: Phytoseiidae) is a cosmopolitan predator of the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae), a significant pest of cotton and maize. Tri-trophic studies were conducted to assess the potential effects of Cry1Ac/Cry2Ab cotton and Cry1F maize on life history parameters (survival rate, development time ...


Dietary Risk Assessment Of V-Atpase A Dsrnas On Monarch Butterfly Larvae, Huipeng Pan, Xiaowei Yang, Keith G. Bidne, Richard L. Hellmich, Blair D. Siegfried, Xuguo Zhou Apr 2019

Dietary Risk Assessment Of V-Atpase A Dsrnas On Monarch Butterfly Larvae, Huipeng Pan, Xiaowei Yang, Keith G. Bidne, Richard L. Hellmich, Blair D. Siegfried, Xuguo Zhou

Richard L Hellmich

By suppressing the expression of genes with essential biological functions, in planta RNAi can negatively affect the development and survival of target pests. As a part of a concerted effort to assess the risks of RNAi transgenic crops on non-target organisms, we developed an in vivo toxicity assay to examine the impacts of ingested dsRNAs incurred to the monarch butterfly, Danaus plexippus (L.), an iconic eco-indicator in North America. To create the worst case scenario, the full-length v-ATPase A cDNAs from the target pest, western corn rootworm, Diabrotica virgifera virgifera, and the non-target D. plexippus were respectively cloned. A 400 ...


Dynamic Role And Importance Of Surrogate Species For Assessing Potential Adverse Environmental Impacts Of Genetically Engineered Insect-Resistant Plants On Non-Target Organisms, Michael Wach, Richard L. Hellmich, Raymond Layton, Jörg Romeis, Patricia G. Gadaleta Apr 2019

Dynamic Role And Importance Of Surrogate Species For Assessing Potential Adverse Environmental Impacts Of Genetically Engineered Insect-Resistant Plants On Non-Target Organisms, Michael Wach, Richard L. Hellmich, Raymond Layton, Jörg Romeis, Patricia G. Gadaleta

Richard L Hellmich

Surrogate species have a long history of use in research and regulatory settings to understand the potentially harmful effects of toxic substances including pesticides. More recently, surrogate species have been used to evaluate the potential effects of proteins contained in genetically engineered insect resistant (GEIR) crops. Species commonly used in GEIR crop testing include beneficial organisms such as honeybees, arthropod predators, and parasitoids. The choice of appropriate surrogates is influenced by scientific factors such as the knowledge of the mode of action and the spectrum of activity as well as societal factors such as protection goals that assign value to ...


Monarch Butterflies Do Not Place All Of Their Eggs In One Basket: Oviposition On Nine Midwestern Milkweed Species, Victoria M. Pocius, Diane M. Debinski, John M. Pleasants, Keith G. Bidne, Richard L. Hellmich Apr 2019

Monarch Butterflies Do Not Place All Of Their Eggs In One Basket: Oviposition On Nine Midwestern Milkweed Species, Victoria M. Pocius, Diane M. Debinski, John M. Pleasants, Keith G. Bidne, Richard L. Hellmich

Richard L Hellmich

Over the past two decades, the population of monarch butterflies east of the Rocky Mountains has experienced a significant decline in overwintering numbers. Habitat restoration that includes planting milkweeds is essential to boost monarch numbers within the breeding range. Milkweeds are the only host plants for larval monarch butterflies, but female oviposition preference for different milkweed species, especially those with overlapping ranges, is not well documented. We examined the relative inclination to lay eggs on nine milkweed species native to Iowa (no choice), and oviposition preference (choice) among the four most commonly occurring Iowa species (Asclepias incarnata, Asclepias syriaca, Asclepias ...


Performance Of Early Instar Monarch Butterflies (Danaus Plexippus L.) On Nine Milkweed Species Native To Iowa, Victoria M. Pocius, Diane M. Debinski, Keith G. Bidne, Richard L. Hellmich, Frances K. Hunter Apr 2019

Performance Of Early Instar Monarch Butterflies (Danaus Plexippus L.) On Nine Milkweed Species Native To Iowa, Victoria M. Pocius, Diane M. Debinski, Keith G. Bidne, Richard L. Hellmich, Frances K. Hunter

Richard L Hellmich

Over the past two decades, the population of monarch butterflies east of the Rocky Mountains has experienced a significant decline. Habitat restoration that includes milkweed plants is crucial to boost population numbers in the breeding range. Monarch butterfly larvae use milkweeds as their only host plant, but larval performance on different milkweed species is not well documented. We examined early instar survival and growth on nine milkweed species native to Iowa. These included Asclepias exaltata (poke milkweed), A. hirtella (tall green milkweed), A. incarnata (swamp milkweed), A. speciosa (showy milkweed), A. sullivantii (prairie milkweed), A. syriaca (common milkweed), A. tuberosa ...


Susceptibility To Bt Proteins Is Not Required For Agrotis Ipsilon Aversion To Bt Maize, Rachel Renee Binning, Joel R. Coats, Xiaoxiao Kong, Richard L. Hellmich Ii Apr 2019

Susceptibility To Bt Proteins Is Not Required For Agrotis Ipsilon Aversion To Bt Maize, Rachel Renee Binning, Joel R. Coats, Xiaoxiao Kong, Richard L. Hellmich Ii

Richard L Hellmich

Although Bacillus thuringiensis (Bt) maize has been widely adopted in diverse regions around the world, relatively little is known about the susceptibility and behavioral response of certain insect pests to Bt maize in countries where this maize is not currently cultivated. These are important factors to consider as management plans are developed. These factors were investigated for Agrotis ipsilon, a global pest of maize, with Cry1F and Cry34Ab1/Cry35Ab1 maize. Agrotis ipsilon demonstrated an initial, post-ingestive aversive response to Cry1F maize. Development and mortality were also affected – survival on Cry1F maize tissue was 40% and weight gain of survivors of ...


Monarch Oviposition And Larval Survivalon Nine Native Milkweed Species Duringthe 2016 Breeding Season, Victoria Pocius, Diane Debinski, Richard Hellmich Apr 2019

Monarch Oviposition And Larval Survivalon Nine Native Milkweed Species Duringthe 2016 Breeding Season, Victoria Pocius, Diane Debinski, Richard Hellmich

Richard L Hellmich

The Iowa Monarch Conservation Consortium was established March 2015. Adding milkweeds to agricultural landscapes is one of many Consortium goals. In order to further monarch butterfly conservation efforts, scientists need more information about milkweed phenology and persistence on the landscape, and how monarchs are using these plants, because milkweeds now are absent from most agricultural fields. This is the second year of a study to examine both oviposition preference and larval survival on nine milkweed species endemic to Iowa. These data will be used as a baseline for informing monarch habitat conservation and restoration efforts across the Midwest.


Monarch Oviposition And Larval Survivalon Nine Native Milkweed Species Duringthe 2016 Breeding Season, Victoria Pocius, Diane Debinski, Richard Hellmich Apr 2019

Monarch Oviposition And Larval Survivalon Nine Native Milkweed Species Duringthe 2016 Breeding Season, Victoria Pocius, Diane Debinski, Richard Hellmich

Richard L Hellmich

The Iowa Monarch Conservation Consortium was established March 2015. Adding milkweeds to agricultural landscapes is one of many Consortium goals. In order to further monarch butterfly conservation efforts, scientists need more information about milkweed phenology and persistence on the landscape, and how monarchs are using these plants, because milkweeds now are absent from most agricultural fields. This is the second year of a study to examine both oviposition preference and larval survival on nine milkweed species endemic to Iowa. These data will be used as a baseline for informing monarch habitat conservation and restoration efforts across the Midwest.


Monarch Oviposition And Larval Survivalon Nine Native Milkweed Species Duringthe 2016 Breeding Season, Victoria Pocius, Diane Debinski, Richard Hellmich Apr 2019

Monarch Oviposition And Larval Survivalon Nine Native Milkweed Species Duringthe 2016 Breeding Season, Victoria Pocius, Diane Debinski, Richard Hellmich

Richard L Hellmich

The Iowa Monarch Conservation Consortium was established March 2015. Adding milkweeds to agricultural landscapes is one of many Consortium goals. In order to further monarch butterfly conservation efforts, scientists need more information about milkweed phenology and persistence on the landscape, and how monarchs are using these plants, because milkweeds now are absent from most agricultural fields. This is the second year of a study to examine both oviposition preference and larval survival on nine milkweed species endemic to Iowa. These data will be used as a baseline for informing monarch habitat conservation and restoration efforts across the Midwest.


Monarch Oviposition And Larval Survivalon Nine Native Milkweed Species Duringthe 2016 Breeding Season, Victoria Pocius, Diane Debinski, Richard Hellmich Apr 2019

Monarch Oviposition And Larval Survivalon Nine Native Milkweed Species Duringthe 2016 Breeding Season, Victoria Pocius, Diane Debinski, Richard Hellmich

Richard L Hellmich

The Iowa Monarch Conservation Consortium was established March 2015. Adding milkweeds to agricultural landscapes is one of many Consortium goals. In order to further monarch butterfly conservation efforts, scientists need more information about milkweed phenology and persistence on the landscape, and how monarchs are using these plants, because milkweeds now are absent from most agricultural fields. This is the second year of a study to examine both oviposition preference and larval survival on nine milkweed species endemic to Iowa. These data will be used as a baseline for informing monarch habitat conservation and restoration efforts across the Midwest.


Monarch Oviposition And Larval Survival On Nine Native Milkweed Species During The 2016 Breeding Season, Victoria Pocius, Diane Debinski, Richard L. Hellmich Apr 2019

Monarch Oviposition And Larval Survival On Nine Native Milkweed Species During The 2016 Breeding Season, Victoria Pocius, Diane Debinski, Richard L. Hellmich

Richard L Hellmich

The Iowa Monarch Conservation Consortium was established March 2015. Adding milkweeds to agricultural landscapes is one of many Consortium goals. In order to further monarch butterfly conservation efforts, scientists need more information about milkweed phenology and persistence on the landscape, and how monarchs are using these plants, because milkweeds now are absent from most agricultural fields. This is the second year of a study to examine both oviposition preference and larval survival on nine milkweed species endemic to Iowa. These data will be used as a baseline for informing monarch habitat conservation and restoration efforts across the Midwest.


Monarch Oviposition And Larval Survivalon Nine Native Milkweed Species Duringthe 2016 Breeding Season, Victoria Pocius, Diane Debinski, Richard Hellmich Apr 2019

Monarch Oviposition And Larval Survivalon Nine Native Milkweed Species Duringthe 2016 Breeding Season, Victoria Pocius, Diane Debinski, Richard Hellmich

Richard L Hellmich

The Iowa Monarch Conservation Consortium was established March 2015. Adding milkweeds to agricultural landscapes is one of many Consortium goals. In order to further monarch butterfly conservation efforts, scientists need more information about milkweed phenology and persistence on the landscape, and how monarchs are using these plants, because milkweeds now are absent from most agricultural fields. This is the second year of a study to examine both oviposition preference and larval survival on nine milkweed species endemic to Iowa. These data will be used as a baseline for informing monarch habitat conservation and restoration efforts across the Midwest.


Monarch Oviposition And Larval Survival On Nine Native Milkweed Species During The 2016 Breeding Season, Victoria Pocius, Diane Debinski, Richard Hellmich Apr 2019

Monarch Oviposition And Larval Survival On Nine Native Milkweed Species During The 2016 Breeding Season, Victoria Pocius, Diane Debinski, Richard Hellmich

Richard L Hellmich

The Iowa Monarch Conservation Consortium was established March 2015. Adding milkweeds to agricultural landscapes is one of many Consortium goals. In order to further monarch butterfly conservation efforts, scientists need more information about milkweed phenology and persistence on the landscape, and how monarchs are using these plants, because milkweeds now are absent from most agricultural fields. This is the second year of a study to examine both oviposition preference and larval survival on nine milkweed species endemic to Iowa. These data will be used as a baseline for informing monarch habitat conservation and restoration efforts across the Midwest.


Of Monarchs And Men: Possible Influence Of Bt Corn In The Agricultural Community, Richard L. Hellmich, Marlin E. Rice, John M. Pleasants, Wai-Ki F. Lam Apr 2019

Of Monarchs And Men: Possible Influence Of Bt Corn In The Agricultural Community, Richard L. Hellmich, Marlin E. Rice, John M. Pleasants, Wai-Ki F. Lam

Richard L Hellmich

Transgenic Bt com has provided unprecedented control of European com borer, Ostrinia nubilalis, without further inputs of less environmentally-friendly insecticides (Caprio et al. 1998). Transgenic com hybrids contain a protein-producing gene derived from Bacillus thuringiensis (Bt) that is toxic to certain insects when it is eaten by the larval stages (Koziel et al. 1993). Farmers had their first opportunity in 1996 to plant transgenic Bt com hybrids that killed European com borers. This protein prevents large amounts of leaf feeding, stalk tunneling and subsequent yield loss caused by European com borer.


On-Plant Selection And Genetic Analysis Of European Corn Borer (Lepidoptera: Crambidae) Behavioral Traits: Plant Abandonment Versus Plant Establishment, Michael A. Rausch, Jeremy A. Kroemer, Aaron J. Gassmann, Richard L. Hellmich Apr 2019

On-Plant Selection And Genetic Analysis Of European Corn Borer (Lepidoptera: Crambidae) Behavioral Traits: Plant Abandonment Versus Plant Establishment, Michael A. Rausch, Jeremy A. Kroemer, Aaron J. Gassmann, Richard L. Hellmich

Richard L Hellmich

Although some studies have investigated how insect behavior could influence resistance evolution to transgenic plants, none have determined if behavioral traits respond to selection pressure and how they may be inherited. We investigated plant establishment and abandonment traits for the European corn borer, Ostrinia nubilalisi (Hübner) (Lepidoptera: Crambidae), by conducting a laboratory selection experiment and quantifying patterns of gene expression. Egg masses with emerging larvae were placed on maize plants and silking individuals were collected every 15 min during a 4-h period to generate a plant abandonment (PA) colony. Plants were dissected 24-72 h later, and larvae were collected for ...


Nontarget Effects Of Bt Corn On Pathogenic And Toxigenic Fungi, Gary P. Munkvold, Walter G. Hyde, Richard L. Hellmich Apr 2019

Nontarget Effects Of Bt Corn On Pathogenic And Toxigenic Fungi, Gary P. Munkvold, Walter G. Hyde, Richard L. Hellmich

Richard L Hellmich

There may be nontarget effects of transgenic corn hybrids, positive and negative, on fungi that interact with the targeted pests. What are the effects of Bt corn on fungi that are associated with corn plants and their insect pests?


Monarch Oviposition And Larval Survival On Nine Native Milkweed Species, Richard Hellmich, Diane Debinski, Victoria Pocius Apr 2019

Monarch Oviposition And Larval Survival On Nine Native Milkweed Species, Richard Hellmich, Diane Debinski, Victoria Pocius

Richard L Hellmich

The Iowa Monarch Conservation Consortium was established in March 2015. Adding milkweeds to agricultural landscapes is one of many Consortium goals. In order to further monarch butterfly conservation efforts, scientists need more information about milkweed phenology and persistence on the landscape, and how monarchs are using these plants because milkweeds are now absent from most agricultural fields. This study is being conducted over multiple years to examine both oviposition preference and larval survival on nine milkweed species endemic to Iowa. These data will be used as a baseline for informing monarch habitat conservation and restoration efforts across the midwest.


Monarch Oviposition And Larval Survival On Nine Native Milkweed Species, Richard L. Hellmich Apr 2019

Monarch Oviposition And Larval Survival On Nine Native Milkweed Species, Richard L. Hellmich

Richard L Hellmich

The Iowa Monarch Conservation Consortium was established in March 2015. Adding milkweeds to agricultural landscapes is one of many Consortium goals. In order to further monarch butterfly conservation efforts, scientists need more information about milkweed phenology and persistence on the landscape, and how monarchs are using these plants because milkweeds are now absent from most agricultural fields. This study is being conducted over multiple years to examine both oviposition preference and larval survival on nine milkweed species endemic to Iowa. These data will be used as a baseline for informing monarch habitat conservation and restoration efforts across the midwest.


Monarch Oviposition And Larval Survival On Nine Native Milkweed Species, Victoria Pocius, Richard Hellmich, Diane Debinski Apr 2019

Monarch Oviposition And Larval Survival On Nine Native Milkweed Species, Victoria Pocius, Richard Hellmich, Diane Debinski

Richard L Hellmich

The Iowa Monarch Conservation Consortium was established in March 2015. Adding milkweeds to agricultural landscapes is one of many Consortium goals. In order to further monarch butterfly conservation efforts, scientists need more information about milkweed phenology and persistence on the landscape, and how monarchs are using these plants because milkweeds are now absent from most agricultural fields. This study was conducted over multiple years to examine both oviposition preference and larval survival on nine milkweed species endemic to Iowa. These data will be used as a baseline for informing monarch habitat conservation and restoration efforts across the Midwest. These are ...


Monarch Oviposition And Larval Survival On Nine Native Milkweed Species, Victoria Pocius, Richard Hellmich, Diane Debinski Apr 2019

Monarch Oviposition And Larval Survival On Nine Native Milkweed Species, Victoria Pocius, Richard Hellmich, Diane Debinski

Richard L Hellmich

The Iowa Monarch Conservation Consortium was established in March 2015. Adding milkweeds to agricultural landscapes is one of many Consortium goals. In order to further monarch butterfly conservation efforts, scientists need more information about milkweed phenology and persistence on the landscape, and how monarchs are using these plants because milkweeds are now absent from most agricultural fields. This study was conducted over multiple years to examine both oviposition preference and larval survival on nine milkweed species endemic to Iowa. These data will be used as a baseline for informing monarch habitat conservation and restoration efforts across the Midwest. These are ...


Comparison Of Fumonisin Contamination Using Hplc And Elisa Methods In Bt And Near-Isogenic Maize Hybrids Infested With European Corn Borer Or Western Bean Cutworm, Erin Louise Bowers, Richard L. Hellmich, Gary P. Munkvold Apr 2019

Comparison Of Fumonisin Contamination Using Hplc And Elisa Methods In Bt And Near-Isogenic Maize Hybrids Infested With European Corn Borer Or Western Bean Cutworm, Erin Louise Bowers, Richard L. Hellmich, Gary P. Munkvold

Richard L Hellmich

Field trials were conducted from 2007 to 2010 to compare grain fumonisin levels among non-Bt maize hybrids and Bt hybrids with transgenic protection against manual infestations of European corn borer (ECB) and Western bean cutworm (WBC). HPLC and ELISA were used to measure fumonisin levels. Results of the methods were highly correlated, but ELISA estimates were higher. Bt hybrids experienced less insect injury, Fusarium ear rot, and fumonisin contamination compared to non-Bt hybrids. WBC infestation increased fumonisin content compared to natural infestation in non-Bt and hybrids expressing Cry1Ab protein in five of eight possible comparisons; in Cry1F ...


Development Of A Model System Approach For Generating Fragments Of The Cry1ab Protein, Vurtice Albright Iii, Richard L. Hellmich, Joel R. Coats Apr 2019

Development Of A Model System Approach For Generating Fragments Of The Cry1ab Protein, Vurtice Albright Iii, Richard L. Hellmich, Joel R. Coats

Richard L Hellmich

The use of transgenic crops expressing one or more crystal (Cry) proteins for insect management has grown dramatically since their introduction nearly 2 decades ago. However, many questions surrounding the environmental fate of these proteins still persist. One area of particular interest is the possible detection of Cry protein fragments by the antibodies used in ELISA kits. A model system approach is used to generate environmentally relevant fragments by simulating conditions and digestive enzymes that are known to exist in environments in which Cry proteins may be present. Seven different types of model systems were screened for their ability to ...


Early Detection And Mitigation Of Resistance To Bt Maize By Western Corn Rootworm (Coleoptera: Chrysomelidae), David A. Andow, Steven G. Pueppke, Arthur W. Schaafsma, Aaron J. Gassmann, Thomas W. Sappington, Lance J. Meinke, Paul D. Mitchell, Terrance M. Hurley, Richard L. Hellmich, R. Pat Porter Apr 2019

Early Detection And Mitigation Of Resistance To Bt Maize By Western Corn Rootworm (Coleoptera: Chrysomelidae), David A. Andow, Steven G. Pueppke, Arthur W. Schaafsma, Aaron J. Gassmann, Thomas W. Sappington, Lance J. Meinke, Paul D. Mitchell, Terrance M. Hurley, Richard L. Hellmich, R. Pat Porter

Richard L Hellmich

Transgenic Bt maize that produces less than a high-dose has been widely adopted and presents considerable insect resistance management (IRM) challenges. Western corn rootworm, Diabrotica virgifera virgifera LeConte, has rapidly evolved resistance to Bt maize in the field, leading to local loss of efficacy for some corn rootworm Bt maize events. Documenting and responding to this resistance has been complicated by a lack of rapid diagnostic bioassays and by regulatory triggers that hinder timely and effective management responses. These failures are of great concern to the scientific and agricultural community. Specific challenges posed by western corn rootworm resistance to Bt ...


A Review Of Cry Protein Detection With Enzyme-Linked Immunosorbent Assays, Vurtice C. Albright Iii, Richard L. Hellmich, Joel R. Coats Apr 2019

A Review Of Cry Protein Detection With Enzyme-Linked Immunosorbent Assays, Vurtice C. Albright Iii, Richard L. Hellmich, Joel R. Coats

Richard L Hellmich

The widespread use of Cry proteins in insecticide formulations and transgenic crops for insect control has led to an increased interest in the environmental fate of these proteins. Although several detection methods are available to monitor the fate of Cry proteins in the environment, enzyme-linked immunosorbent assays (ELISAs) have emerged as the preferred detection method, due to their cost-effectiveness, ease of use, and rapid results. Validation of ELISAs is necessary to ensure accurate measurements of Cry protein concentrations in the environment. Validation methodology has been extensively researched and published for the areas of sensitivity, specificity, accuracy, and precision; however, cross ...


Biotechnology And Pest Resistance: An Economic Assessment Of Refuges, Terrance M. Hurley, Bruce A. Babcock, Richard L. Hellmich Apr 2019

Biotechnology And Pest Resistance: An Economic Assessment Of Refuges, Terrance M. Hurley, Bruce A. Babcock, Richard L. Hellmich

Richard L Hellmich

Biologists now engineer transgenic crop varieties that offer farmers a new tool for effectively managing pests. Concern over pest resistance, however, has prompted the Environmental Protection Agency to require resistance management plans. This paper develops an economic model of pest management with pest resistance to estimate the constant proportion of cropland planted in refuge that maximizes farm income over a fixed planning horizon. Results indicate a clear economic tradeoff between the pest control benefits of a transgenic variety and the resistance management benefits afforded by refuge.


Monarch Butterflies And Bt Corn: Replacing Hoopla With Science, Richard L. Hellmich, John M. Pleasants, Leslie C. Lewis Apr 2019

Monarch Butterflies And Bt Corn: Replacing Hoopla With Science, Richard L. Hellmich, John M. Pleasants, Leslie C. Lewis

Richard L Hellmich

A correspondence to Nature three years ago reported a preliminary laboratory study that suggested pollen from from Bacillus thuringiensis (Bt) com could be hazardous to the larvae of the monarch butterfly, Danaus plexippus. Losey et al. (1999) showed that young monarch larvae given no choice but to feed on milkweed, Asclepias curassavica, leaves dusted with pollen from Bt corn hybrid ate less, grew more slowly, and had a significantly higher mortality rate than larvae feeding on leaves dusted with nontransgenic pollen. Based on this study, the authors questioned the environmental safety of Bt com and called for scientific investigations.


Monarch Oviposition And Larval Survival On Nine Native Milkweed Species, Victoria Pocius, Richard Hellmich, Diane Debinski Apr 2019

Monarch Oviposition And Larval Survival On Nine Native Milkweed Species, Victoria Pocius, Richard Hellmich, Diane Debinski

Richard L Hellmich

The Iowa Monarch Conservation Consortium was established in March 2015. Adding milkweeds to agricultural landscapes is one of many Consortium goals. In order to further monarch butterfly conservation efforts, scientists need more information about milkweed phenology and persistence on the landscape, and how monarchs are using these plants because milkweeds are now absent from most agricultural fields. This study was conducted over multiple years to examine both oviposition preference and larval survival on nine milkweed species endemic to Iowa. These data will be used as a baseline for informing monarch habitat conservation and restoration efforts across the Midwest. These are ...