Plant latex and first-instar monarch larval growth and survival on three North American milkweed species

First-instar larvae of the monarch butterfly, Danaus plexippus, a milkweed specialist, generally grew faster and survived better on leaves when latex flow was reduced by partial severance of the leaf petiole. The outcome depended on milkweed species and was related to the amount of latex produced. The outcome also may be related to the amount of cardenolide produced by the plants as a potential chemical defense against herbivory. Growth was more rapid, but survival was similar on partially severed compared with intact leaves of the high-latex/low-cardenolide milkweed, Asclepias syriaca, whereas both growth and survival were unaffected on the low-latex/low-cardenolide milkweed A. incarnata. On the low-latex/low-cardenolide milkweed A. tuberosa, both growth and survival of larvae were only marginally affected. These results contrast sharply to previous results with the milkweed, A. humistrata, in Florida, which has both high latex and high cardenolide. Larval growth and survival on A. humistrata were both increased by partially severing leaf petioles. Larval growth rates among all four milkweed species on leaves with partially severed petioles were identical, suggesting that latex and possibly the included cardenolides are important in first-instar monarch larval growth, development, and survivorship.

Detrimental effects of latex and cardiac glycosides on survival and growth of first-instar monarch butterfly larvae Danaus plexippus feeding on the sandhill milkweed Asclepias humistrata

1. A novel experimental method was developed to study negative physical and chemical effects of latex and cardiac glycosides on first-instar monarch butterfly larvae in their natural environment in north central Florida. Forceps were used to nibble through the petioles of leaves of the sandhill milkweed Asclepias humistrata, mimicking the behaviour of mature monarch larvae. This notching cut off the supply-of latex to the leaves without significantly reducing either their cardiac glycoside concentration or water content. 2. The mean cardiac glycoside concentration in larvae that fed on intact leaves was nearly two: and a half times greater than in larvae that fed on notched leaves. This was probably because more latex is present in the gut of the larvae that fed on the intact leaves. Supporting this is the fact that the mean concentration of cardiac glycosides in the latex was 34-47 times that in the leaves. 3. Wet weights, dry weights, and growth rates of first-instar larvae that fed on intact leaves over a 72-h period were less than half those of larvae that fed on notched leaves. 4. Mortality due to miring in the latex was 27% on the intact leaves compared with 2% on the notched leaves. 5. Latex, cardiac glycosides, and other as yet undetermined plant factors all have a negative effect on:first-instar larval survival. 6. Video-analyses indicated that ingestion of latex caused the larvae to become cataleptic and increased their chances of being mired on the leaf by the setting latex glue. Dysfunction resulting from latex ingestion may lead to the larvae falling off the plant and being killed by invertebrate predators. 7. The difficulty of neonate monarch larvae surviving on A. humistrata - one of the principal milkweed species fed on each spring as monarchs remigrate from Mexico into the southern U.S.A. - is evidence that a co-evolutionary arms race is operating in this plant-herbivore system.

Genetic differentiation between Australian and North American populations of the monarch butterfly Danaus plexippus (L.) (Lepidoptera : Nymphalidae): an exploration using allozyme electrophoresis

Allozyme analysis was used to address the question of the source of the Australian populations of the monarch butterfly Danaus plexippus (L.). The study had three major aims: (1) To compare the levels of diversity of Australian and Hawaiian populations with potential source populations. (2) To determine whether eastern and western North American populations were sufficiently divergent for the Australian populations to be aligned to a source population. (3) To compare the differentiation among regions in Australia and North America to test the prediction of greater genetic structure in Australia, as a consequence of reduced migratory behaviour. The reverse was found, with F-ST values an order of magnitude lower in Australia than in North America. Predictably, Australian and Hawaiian populations had lower allelic diversity, but unexpected higher heterozygosity values than North American populations. It was not possible to assign the Australian populations to a definitive source, although the high levels of similarity of Australian populations to each other suggest a single colonization event. The possibility that the Australian populations have not been here long enough to reach equilibrium is discussed. (C) 2002 The Linnean Society of London, Biological Journal of the Linnean Society, 2002, 75, 437-452.

Risk sharing with the monarch: Excusable defaults and contingent debt in the age of Philip II, 1556-1598

Contingent sovereign debt can create important welfare gains. Nonetheless,there is almost no issuance today. Using hand-collected archival data, we examine thefirst known case of large-scale use of state-contingent sovereign debt in history. Philip IIof Spain entered into hundreds of contracts whose value and due date depended onverifiable, exogenous events such as the arrival of silver fleets. We show that this allowedfor effective risk-sharing between the king and his bankers. The data also stronglysuggest that the defaults that occurred were excusable they were simply contingenciesover which Crown and bankers had not contracted previously.

The Dark Monarch: magic and modernity in British art

This major curated exhibition, publication and events builds on Rowlands’ curatorial research. Working in collaboration with co-curators Martin Clark, Artistic Director, Tate St Ives and Michael Bracewell, cultural historian, the exhibition sought to explore new narratives within British art. The innovative curatorial methodology developed from a fiction found in the infamous novel, The Dark Monarch by Sven Berlin, Gallery Press 1962. The research sought specific archival and collection work that allowed thematic strands to emerge that represented influences across generations. The exhibition features two-hundred artworks, from the Tate Collection, archives and other significant British public and private collections. It examines the development of early Modernism, in the UK, as well as the reappearance of esoteric and arcane references in a significant strand of contemporary art practice. Historical works from Samuel Palmer, Graham Sutherland, Henry Moore and Paul Nash are shown alongside contemporary artists including Derek Jarman, Cerith Wyn Evans, Eva Rothschild, Linder and John Russell. The exhibition includes a key work by Damien Hirst ¬ the first time he has been shown at Tate St Ives and a number of contemporary commissions. The Dark Monarch publication extended the discourse of the research critically examining the tension between progressive modernity and romantic knowledge, the book focuses on the way that artworks are encoded with various histories - geological, mythical and magical. Essays examine magic as a counterpoint to modernity’s transparency and rational progress, but also draw out the links modernity has with notions such as fetishism, mana, totem, and the taboo. Often viewed as counter to Modernism, this collection of essays suggest that these products of illusion and delusion in fact belong to modernity. Drawing together 15 different writers commissioned to explore magic as a counterpoint of liberal understanding of modernity, drawing out links that modernity has with notions of fetish, taboo and occult philosophy. Including essays by Marina Warner, Ilsa Colsell, Philip Hoare, Chris Stephens, Jennifer Higgie and Morrissey.

Victoria! unser guter Kaiser kommt: Unser guter innigstgeliebter Kaiser, unser gnädigster Monarch kommt zurück ...

Welsch (Projektbearbeiter): Äußerung von Freude und Genugtuung über die bevorstehende Rückkehr Kaiser Ferdinands I. nach Wien (die tatsächlich erst am 12. August 1848 erfolgt)

"The harp the monarch minstrel swept" [Rezension]

L. H.

Monarch butterflies (Danaus plexippus L.) use a magnetic compass for navigation

Fall migratory monarch butterflies, tested for their directional responses to magnetic cues under three conditions, amagnetic, normal, and reversed magnetic fields, showed three distinct patterns. In the absence of a magnetic field, monarchs lacked directionality as a group. In the normal magnetic field, monarchs oriented to the southwest with a group pattern typical for migrants. When the horizontal component of the magnetic field was reversed, the butterflies oriented to the northeast. In contrast, nonmigratory monarchs lacked directionality in the normal magnetic field. The results are a direct demonstration of magnetic compass orientation in migratory insects.

Natal origins of migratory monarch butterflies at wintering colonies in Mexico: New isotopic evidence

Each year, millions of monarch butterflies from eastern North America migrate to overwinter in 10–13 discrete colonies located in the Oyamel forests of central Mexico. For decades efforts to track monarch migration have relied on observations and tag-recapture methods, culminating with the discovery of the wintering colonies in 1975. Monarch tag returns from Mexico, however, are few and primarily from two accessible colonies, and therefore tag-recapture techniques have not quantified natal origins or distinctiveness among monarch populations at wintering sites. Such information would be invaluable in the conservation of the monarch and its migration phenomenon since the wintering sites currently are threatened by habitat alteration. Here we show that stable hydrogen (δD) and carbon (δ13C) isotope ratios of wintering monarchs can be used to evaluate natal origins on the summer breeding range. Stable-hydrogen and carbon isotopic values of 597 wintering monarchs from 13 wintering roost sites were compared with isotopic patterns measured in individuals at natal sites across their breeding range over a single migration cycle. We determined that all monarch wintering colonies were composed of individuals originating mainly from the Midwest, United States, thereby providing evidence for a panmictic model of wintering colony composition. However, two colonies showed more northerly origins, suggesting possible priority colonies for conservation efforts.

The reign of Richard II and comments upon an alternative poem on the deposition of that monarch /

Mode of access: Internet.

An heroic epistle to an unfortunate monarch,

A satire upon George III.

Authentic memoirs of our late venerable and beloved monarch, George the Third ...

Mode of access: Internet.

Memoirs of Maximilian de Bethune, duke of Sully, prime minister to Henry the Great. Containing the history of the life and reign of that monarch, and his own administration under him /

Mode of access: Internet.

The coming prince : the last great monarch of Christendom /

Includes bibliographical references and index.