scholarly journals Predators of monarch butterfly eggs and neonate larvae are more diverse than previously recognised

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sara L. Hermann ◽  
Carissa Blackledge ◽  
Nathan L. Haan ◽  
Andrew T. Myers ◽  
Douglas A. Landis

Abstract Conserving threatened organisms requires knowledge of the factors impacting their populations. The Eastern monarch butterfly (Danaus plexippus L.) has declined by as much as 80% in the past two decades and conservation biologists are actively seeking to understand and reverse this decline. While it is well known that most monarchs die as eggs and young larvae, few studies have focused on identifying what arthropod taxa contribute to these losses. The aim of our study was to identify previously undocumented predators of immature monarchs in their summer breeding range in the United States. Using no-choice feeding assays augmented with field observations, we evaluated 75 arthropod taxa commonly found on the primary host plant for their propensity to consume immature monarchs. Here we report 36 previously unreported monarch predators, including representatives from 4 new orders (Orthoptera, Dermaptera, Lepidoptera and Opiliones) and 11 taxa (Acrididae, Gryllidae, Tettigoniidae, Forficulidae, Anthocoridae, Geocoridae, Lygaeidae, Miridae, Nabidae, Erebidae and Opilliones). Surprisingly, several putative herbivores were found to readily consume immature monarchs, both in a targeted fashion or incidentally as a result of herbivory. This work expands our understanding of the monarch predator community and highlights the importance of unrecognized predation on insects of conservation concern.

2019 ◽  
Vol 116 (8) ◽  
pp. 3006-3011 ◽  
Author(s):  
J. H. Boyle ◽  
H. J. Dalgleish ◽  
J. R. Puzey

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.


2018 ◽  
Author(s):  
JH Boyle ◽  
HJ Dalgleish ◽  
JR Puzey

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.


1997 ◽  
Vol 129 (2) ◽  
pp. 375-376 ◽  
Author(s):  
Eduardo Rivera García ◽  
Miguel E. Equihua Zamora

Danausplexippus L. (Lepidoptera: Nymphalidae) is a cosmopolitan species, distributed in America wherever milkweed grows (Amett 1985). Its migratory phenomenon spans Canada, the United States, and Mexico and it has been considered endangered since the 1980s (IUCN 1983).Ackery and Van-Wright (1984) compiled 45 species of food plants used by immature stages and 70 species of plants attractive to adults of the Monarch butterfly. Malcolm and Brower (1986) listed 28 host plant species recorded in nature. Lynch and Martin (1993) added six Asclepias species and observed larvae on three species of milkweed vine, Sarcostemma crispum and S. cynancroides in Texas, and Cynanchum laeve in Louisiana.


Author(s):  
Ella Inglebret ◽  
Amy Skinder-Meredith ◽  
Shana Bailey ◽  
Carla Jones ◽  
Ashley France

The authors in this article first identify the extent to which research articles published in three American Speech-Language-Hearing Association (ASHA) journals included participants, age birth to 18 years, from international backgrounds (i.e., residence outside of the United States), and go on to describe associated publication patterns over the past 12 years. These patterns then provide a context for examining variation in the conceptualization of ethnicity on an international scale. Further, the authors examine terminology and categories used by 11 countries where research participants resided. Each country uses a unique classification system. Thus, it can be expected that descriptions of the ethnic characteristics of international participants involved in research published in ASHA journal articles will widely vary.


Crisis ◽  
2020 ◽  
pp. 1-5
Author(s):  
Shannon Lange ◽  
Courtney Bagge ◽  
Charlotte Probst ◽  
Jürgen Rehm

Abstract. Background: In recent years, the rate of death by suicide has been increasing disproportionately among females and young adults in the United States. Presumably this trend has been mirrored by the proportion of individuals with suicidal ideation who attempted suicide. Aim: We aimed to investigate whether the proportion of individuals in the United States with suicidal ideation who attempted suicide differed by age and/or sex, and whether this proportion has increased over time. Method: Individual-level data from the National Survey on Drug Use and Health (NSDUH), 2008–2017, were used to estimate the year-, age category-, and sex-specific proportion of individuals with past-year suicidal ideation who attempted suicide. We then determined whether this proportion differed by age category, sex, and across years using random-effects meta-regression. Overall, age category- and sex-specific proportions across survey years were estimated using random-effects meta-analyses. Results: Although the proportion was found to be significantly higher among females and those aged 18–25 years, it had not significantly increased over the past 10 years. Limitations: Data were self-reported and restricted to past-year suicidal ideation and suicide attempts. Conclusion: The increase in the death by suicide rate in the United States over the past 10 years was not mirrored by the proportion of individuals with past-year suicidal ideation who attempted suicide during this period.


2013 ◽  
Vol 10 (2) ◽  
pp. 115-124
Author(s):  
Philip L. Martin

Japan and the United States, the world’s largest economies for most of the past half century, have very different immigration policies. Japan is the G7 economy most closed to immigrants, while the United States is the large economy most open to immigrants. Both Japan and the United States are debating how immigrants are and can con-tribute to the competitiveness of their economies in the 21st centuries. The papers in this special issue review the employment of and impacts of immigrants in some of the key sectors of the Japanese and US economies, including agriculture, health care, science and engineering, and construction and manufacturing. For example, in Japanese agriculture migrant trainees are a fixed cost to farmers during the three years they are in Japan, while US farmers who hire mostly unauthorized migrants hire and lay off workers as needed, making labour a variable cost.


Author(s):  
Pierre Rosanvallon

It's a commonplace occurrence that citizens in Western democracies are disaffected with their political leaders and traditional democratic institutions. But this book argues that this crisis of confidence is partly a crisis of understanding. The book makes the case that the sources of democratic legitimacy have shifted and multiplied over the past thirty years and that we need to comprehend and make better use of these new sources of legitimacy in order to strengthen our political self-belief and commitment to democracy. Drawing on examples from France and the United States, the book notes that there has been a major expansion of independent commissions, NGOs, regulatory authorities, and watchdogs in recent decades. At the same time, constitutional courts have become more willing and able to challenge legislatures. These institutional developments, which serve the democratic values of impartiality and reflexivity, have been accompanied by a new attentiveness to what the book calls the value of proximity, as governing structures have sought to find new spaces for minorities, the particular, and the local. To improve our democracies, we need to use these new sources of legitimacy more effectively and we need to incorporate them into our accounts of democratic government. This book is an original contribution to the vigorous international debate about democratic authority and legitimacy.


2009 ◽  
Vol 1 (1) ◽  
pp. 93-116 ◽  
Author(s):  
Mauricio Tenorio-Trillo

By identifying two general issues in recent history textbook controversies worldwide (oblivion and inclusion), this article examines understandings of the United States in Mexico's history textbooks (especially those of 1992) as a means to test the limits of historical imagining between U. S. and Mexican historiographies. Drawing lessons from recent European and Indian historiographical debates, the article argues that many of the historical clashes between the nationalist historiographies of Mexico and the United States could be taught as series of unsolved enigmas, ironies, and contradictions in the midst of a central enigma: the persistence of two nationalist historiographies incapable of contemplating their common ground. The article maintains that lo mexicano has been a constant part of the past and present of the US, and lo gringo an intrinsic component of Mexico's history. The di erences in their historical tracks have been made into monumental ontological oppositions, which are in fact two tracks—often overlapping—of the same and shared con ictual and complex experience.


2007 ◽  
Vol 5 (1) ◽  
pp. 12-32
Author(s):  
ShiPu Wang

This essay delineates the issues concerning AAPI art exhibitions from a curator’s perspective, particularly in response to the changing racial demographics and economics of the past decades. A discussion of practical, curatorial problems offers the reader an overview of the obstacles and reasons behind the lack of exhibitions of AAPI works in the United States. It is the author’s hope that by understanding the challenges particular to AAPI exhibitions, community leaders, and patrons will direct future financial support to appropriate museum operations, which in turn will encourage more exhibitions and research of the important artistic contribution of AAPI artists to American art.


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