scholarly journals Milkweed loss in agricultural fields because of herbicide use: effect on the monarch butterfly population: Herbicide use and monarch butterflies

2017 ◽  
Author(s):  
John M. Pleasants ◽  
Karen S. Oberhauser
Keyword(s):  
Population Size ◽  
Genetically Modified ◽  
Monarch Butterfly ◽  
Agricultural Fields ◽  
Monarch Butterflies ◽  
Glyphosate Herbicide ◽  
Butterfly Population ◽  
Conservation Threats ◽  
Herbicide Use ◽  
The U.S

1. The size of the Mexican overwintering population of monarch butterflieshas decreased over the last decade. Approximately half of these butterflies comefrom the U.S. Midwest where larvae feed on common milkweed. There has been alarge decline in milkweed in agricultural fields in the Midwest over the last decade.This loss is coincident with the increased use of glyphosate herbicide in conjunctionwith increased planting of genetically modified (GM) glyphosate-tolerant corn(maize) and soybeans (soya).2. We investigate whether the decline in the size of the overwintering populationcan be attributed to a decline in monarch production owing to a loss of milkweeds inagricultural fields in the Midwest. We estimate Midwest annual monarch productionusing data on the number of monarch eggs per milkweed plant for milkweeds in differenthabitats, the density of milkweeds in different habitats, and the area occupiedby those habitats on the landscape.3. We estimate that there has been a 58% decline in milkweeds on the Midwestlandscape and an 81% decline in monarch production in the Midwest from 1999 to2010. Monarch production in the Midwest each year was positively correlated withthe size of the subsequent overwintering population in Mexico. Taken together, theseresults strongly suggest that a loss of agricultural milkweeds is a major contributorto the decline in the monarch population.4. The smaller monarch population size that has become the norm will make thespecies more vulnerable to other conservation threats.

scholarly journals Monarch butterfly and milkweed declines substantially predate the use of genetically modified crops

2019 ◽  
Vol 116 (8) ◽  
pp. 3006-3011 ◽  
Author(s):  
J. H. Boyle ◽  
H. J. Dalgleish ◽  
J. R. Puzey
Keyword(s):  
Genetically Modified ◽  
Danaus Plexippus ◽  
Genetically Modified Crops ◽  
Monarch Butterfly ◽  
The United States ◽  
Gm Crops ◽  
Herbicide Resistant ◽  
The Past ◽  
Scientific Attention ◽  
Herbicide Use

Monarch butterfly (Danaus plexippus) decline over the past 25 years has received considerable public and scientific attention, in large part because its decline, and that of its milkweed (Asclepias spp.) host plant, have been linked to genetically modified (GM) crops and associated herbicide use. Here, we use museum and herbaria specimens to extend our knowledge of the dynamics of both monarchs and milkweeds in the United States to more than a century, from 1900 to 2016. We show that both monarchs and milkweeds increased during the early 20th century and that recent declines are actually part of a much longer-term decline in both monarchs and milkweed beginning around 1950. Herbicide-resistant crops, therefore, are clearly not the only culprit and, likely, not even the primary culprit: Not only did monarch and milkweed declines begin decades before GM crops were introduced, but other variables, particularly a decline in the number of farms, predict common milkweed trends more strongly over the period studied here.

scholarly journals Monarch butterfly and milkweed declines substantially predate the use of genetically modified crops

2018 ◽  
Author(s):  
JH Boyle ◽  
HJ Dalgleish ◽  
JR Puzey
Keyword(s):  
Genetically Modified ◽  
Danaus Plexippus ◽  
Genetically Modified Crops ◽  
Monarch Butterfly ◽  
The United States ◽  
Gm Crops ◽  
Herbicide Resistant ◽  
The Past ◽  
Scientific Attention ◽  
Herbicide Use

AbstractMonarch butterfly (Danaus plexippus) decline over the past 25 years has received considerable public and scientific attention, in large part because its decline, and that of its milkweed (Asclepias spp.) host plant, have been linked to genetically modified (GM) crops and the associated herbicide use. Therefore, the monarch has emerged as a poster child for the anti-GM movement. Here we use museum and herbaria specimens to extend our knowledge of the dynamics of both monarchs and milkweeds in the United States to more than a century, from 1900-2016. We show that monarch population trends closely follow those of their milkweed hosts; that both monarchs and milkweeds increased during the early 20th century, and that recent declines are actually part of a much longer term decline in both monarchs and milkweed beginning around 1950. Herbicide resistant crops, therefore, are clearly not the only culprit, and likely not even the primary culprit, as these declines began decades before GM crops were introduced.

scholarly journals Density estimates of monarch butterflies overwintering in central Mexico

2017 ◽  
Author(s):  
Wayne Thogmartin ◽  
Jay E Diffendorfer ◽  
Laura Lopez-Hoffman ◽  
Karen Oberhauser ◽  
John Pleasants ◽  
...  
Keyword(s):  
Population Size ◽  
Population Decline ◽  
Danaus Plexippus ◽  
Mixture Distribution ◽  
Monarch Butterfly ◽  
Accurate Estimate ◽  
Monarch Butterflies ◽  
Density Estimates ◽  
Considerable Uncertainty ◽  
Log Normal

Given the rapid population decline and recent petition for listing of the monarch butterfly (Danaus plexippus L.) under the Endangered Species Act, an accurate estimate of the Eastern, migratory population size is needed. Because of difficulty in counting individual monarchs, the number of hectares occupied by monarchs in the overwintering area is commonly used as a proxy for population size, which is then multiplied by the density of individuals per hectare to estimate population size. There is, however, considerable variation in published estimates of overwintering density, ranging from 6.9–60.9 million ha-1. We develop a probability distribution for overwinter density of monarch butterflies from six published density estimates. The mean density among the mixture of the six published estimates was ~27.9 million butterflies ha-1 (95% CI: 2.4–80.7 million ha-1); the mixture distribution is approximately log-normal, and as such is better represented by the median (21.1 million butterflies ha-1). Based upon assumptions regarding the number of milkweed needed to support monarchs, the amount of milkweed (Asclepias spp.) lost (0.86 billion stems) in the northern U.S. plus the amount of milkweed remaining (1.34 billion stems), we estimate >1.8 billion stems is needed to return monarchs to an average population size of 6 ha. Considerable uncertainty exists in this required amount of milkweed because of the considerable uncertainty occurring in overwinter density estimates. Nevertheless, the estimate is on the same order as other published estimates. The studies included in our synthesis differ substantially by year, location, method, and measures of precision. A better understanding of the factors influencing overwintering density across space and time would be valuable for increasing the precision of conservation recommendations.

scholarly journals Density estimates of monarch butterflies overwintering in central Mexico

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3221 ◽  
Author(s):  
Wayne E. Thogmartin ◽  
Jay E. Diffendorfer ◽  
Laura López-Hoffman ◽  
Karen Oberhauser ◽  
John Pleasants ◽  
...  
Keyword(s):  
Population Size ◽  
Population Decline ◽  
Danaus Plexippus ◽  
Mixture Distribution ◽  
Monarch Butterfly ◽  
Accurate Estimate ◽  
Monarch Butterflies ◽  
Density Estimates ◽  
Considerable Uncertainty ◽  
Log Normal

Given the rapid population decline and recent petition for listing of the monarch butterfly (Danaus plexippus L.) under the Endangered Species Act, an accurate estimate of the Eastern, migratory population size is needed. Because of difficulty in counting individual monarchs, the number of hectares occupied by monarchs in the overwintering area is commonly used as a proxy for population size, which is then multiplied by the density of individuals per hectare to estimate population size. There is, however, considerable variation in published estimates of overwintering density, ranging from 6.9–60.9 million ha−1. We develop a probability distribution for overwinter density of monarch butterflies from six published density estimates. The mean density among the mixture of the six published estimates was ∼27.9 million butterflies ha−1 (95% CI [2.4–80.7] million ha−1); the mixture distribution is approximately log-normal, and as such is better represented by the median (21.1 million butterflies ha−1). Based upon assumptions regarding the number of milkweed needed to support monarchs, the amount of milkweed (Asclepias spp.) lost (0.86 billion stems) in the northern US plus the amount of milkweed remaining (1.34 billion stems), we estimate >1.8 billion stems is needed to return monarchs to an average population size of 6 ha. Considerable uncertainty exists in this required amount of milkweed because of the considerable uncertainty occurring in overwinter density estimates. Nevertheless, the estimate is on the same order as other published estimates. The studies included in our synthesis differ substantially by year, location, method, and measures of precision. A better understanding of the factors influencing overwintering density across space and time would be valuable for increasing the precision of conservation recommendations.

scholarly journals Density estimates of monarch butterflies overwintering in central Mexico

2017 ◽  
Author(s):  
Wayne Thogmartin ◽  
Jay E Diffendorfer ◽  
Laura Lopez-Hoffman ◽  
Karen Oberhauser ◽  
John Pleasants ◽  
...  
Keyword(s):  
Population Size ◽  
Population Decline ◽  
Danaus Plexippus ◽  
Mixture Distribution ◽  
Monarch Butterfly ◽  
Accurate Estimate ◽  
Monarch Butterflies ◽  
Density Estimates ◽  
Considerable Uncertainty ◽  
Log Normal

Given the rapid population decline and recent petition for listing of the monarch butterfly (Danaus plexippus L.) under the Endangered Species Act, an accurate estimate of the Eastern, migratory population size is needed. Because of difficulty in counting individual monarchs, the number of hectares occupied by monarchs in the overwintering area is commonly used as a proxy for population size, which is then multiplied by the density of individuals per hectare to estimate population size. There is, however, considerable variation in published estimates of overwintering density, ranging from 6.9–60.9 million ha-1. We develop a probability distribution for overwinter density of monarch butterflies from six published density estimates. The mean density among the mixture of the six published estimates was ~27.9 million butterflies ha-1 (95% CI: 2.4–80.7 million ha-1); the mixture distribution is approximately log-normal, and as such is better represented by the median (21.1 million butterflies ha-1). Based upon assumptions regarding the number of milkweed needed to support monarchs, the amount of milkweed (Asclepias spp.) lost (0.86 billion stems) in the northern U.S. plus the amount of milkweed remaining (1.34 billion stems), we estimate >1.8 billion stems is needed to return monarchs to an average population size of 6 ha. Considerable uncertainty exists in this required amount of milkweed because of the considerable uncertainty occurring in overwinter density estimates. Nevertheless, the estimate is on the same order as other published estimates. The studies included in our synthesis differ substantially by year, location, method, and measures of precision. A better understanding of the factors influencing overwintering density across space and time would be valuable for increasing the precision of conservation recommendations.

scholarly journals Resilience or Catastrophe? A possible state change for monarch butterflies in the West

2021 ◽  
Author(s):  
Elizabeth Crone ◽  
Cheryl Schultz
Keyword(s):  
Sudden Change ◽  
Protozoan Parasite ◽  
Monarch Butterfly ◽  
Western United States ◽  
State Change ◽  
Recent Past ◽  
The West ◽  
Monarch Butterflies ◽  
Resident Population ◽  
Butterfly Population

In the western United States, the population of migratory monarch butterflies is on the brink of collapse, having dropped from several million butterflies at coastal overwintering sites in the 1980’s to about 2000 butterflies in the winter of 2020-21. At the same time, a resident (non-migratory) monarch butterfly population in urban gardens seems to be expanding northward. If anything, this urban population has been growing in recent years. We explore the meaning of these changes. The new resident population is not sufficient to make up for the loss of the migratory population; there are still orders of magnitude fewer butterflies now than in the recent past. The resident population also probably lacks the demographic capacity to expand its range inland during summer months, due to higher levels of infection by a protozoan parasite, and subsequently lower survival and fecundity. Nonetheless, the resident population may have the capacity to persist. This sudden change emphasizes the extent to which environmental change can have unexpected consequences. It also demonstrates how quickly these changes can happen. We hope it will provoke discussion about how we define resilience and viability in changing environments.

scholarly journals Social Acceptance for Commercialization of Genetically Modified Food Animals

2021 ◽  
Author(s):  
Ziyao Fan ◽  
Yulian Mu ◽  
Tad Sonstegard ◽  
Xiaomei Zhai ◽  
Kui Li ◽  
...  
Keyword(s):  
Natural Variation ◽  
Social Acceptance ◽  
Genetically Modified ◽  
Genetically Modified Food ◽  
The Public ◽  
Global Challenge ◽  
Social License ◽  
Food Animals ◽  
Natural Mutation ◽  
The U.S

Abstract Genetically modified food animals (GMFAs) are needed to address early the cumulative effects of livestock production on the environment and to accommodate future food demands. In 2020 China and the U.S., the world's two largest economies, embarked on regulatory reforms to boost the commercialization of such animals. However, gaining social acceptance of GMFAs for commercialization remains a global challenge. We propose a framework that focuses on social license for commercialization of GMFAs by defining four classes of improvement using precision genetics: 1) animals equivalent to natural variation to obtain the improved effect of cross-breeding (ENV); 2) animals with an inactivated gene that could occur via natural mutation (ENC-); 3) animals harboring a natural genetic sequence isolated from another species (ENC+); and 4) animals with synthetic sequences encoding novel genes (BNE). Our approach can guide regulators and the public to support orderly commercialization of genetically modified food animals.

Notice of Other Documents

1975 ◽  
Vol 14 (1) ◽  
pp. 314-314
Keyword(s):  
Population Size ◽  
Arms Control ◽  
Armed Forces ◽  
Government Printing ◽  
Arms Trade ◽  
Military Expenditures ◽  
The U.S

The report issued by the U.S. Arms Control and Disarmament Agency, in January 1975, concerns arms expenditures and sales made between 1963 and 1973. The 123-page document is composed mostly of two major parts: a country-by-country breakdown of arms trade for each of the years studied and a study contrasting each country's yearly military expenditures with its G.N.P., population size, and armed forces. The report (U.S. A.CD.A. Publication 74) may be purchased from the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 for $2. Persons ordering from abroad (other than Canada and Mexico) should add 25 percent to the price to cover shipping charges.

scholarly journals Consumer Attitudes toward the Use of Gene Technology in Breakfast Products: Comparison between College Students from the U.S. and China

2015 ◽  
Vol 4 (6) ◽  
pp. 143 ◽  
Author(s):  
Nanying Wang ◽  
Jack E. Houston ◽  
Gregory Colson ◽  
Zimin Liu
Keyword(s):  
College Students ◽  
Consumer Preferences ◽  
Genetically Modified ◽  
Marketing Strategies ◽  
Chinese Market ◽  
Developed Country ◽  
Information Campaigns ◽  
Gm Foods ◽  
Survey Results ◽  
The U.S

Second-generation Genetically Modified (GM) crops are associated with consumer-oriented benefits such as improvement of nutritional quality. Given such an evolving market environment, this paper presents differences in consumer preferences and valuations for genetically modified breakfast grain products. The perception of consumers from a developing country, China, is discussed and compared to attitudes in a developed country, the U.S. The survey results reveal that there are notable differences in the attitude and perception of college students across these two countries. Purchase intent for GM foods was low, unless a benefit was promised, and some modifications are viewed more positively than others. Overall, it appears that GM foods may be acceptable in the U.S. and Chinese market. The findings in this study have potential implications for establishing various GM marketing strategies and information campaigns.

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