scholarly journals Flying through hurricane central: impacts of hurricanes on migrants with a focus on monarch butterflies

2018 ◽  
Vol 5 (1) ◽  
pp. 94-103 ◽  
Author(s):  
Leslie Ries ◽  
Naresh Neupane ◽  
Kristen A. Baum ◽  
Elise F. Zipkin
Keyword(s):  
Danaus Plexippus ◽  
Monarch Butterfly ◽  
Migratory Bird ◽  
Migratory Species ◽  
Vegetation Growth ◽  
Critical Studies ◽  
Good Target ◽  
Indirect Impacts ◽  
Critical Resources ◽  
Migratory Pathway

Abstract Hurricanes are becoming more frequent and intense, so understanding the consequences for biodiversity, including migratory species, has become critical. Studies suggest that migrants may avoid most of the direct harm of hurricanes by shifting their flight trajectories to less-impacted regions, but the majority of this research has focused on birds. We review the literature on migratory bird responses to hurricanes and also describe other taxa likely to be affected. We then focus on the monarch butterfly (Danaus plexippus), whose fall migratory pathway goes through Texas during hurricane season. Like birds, monarchs may be able to avoid direct damage from hurricanes. However, it may be more important to determine how they respond to shifts in availability of critical resources during migration. In fall, when a storm-triggered flush of out-of-season vegetation growth is especially likely, hurricanes could reasonably cause indirect impacts that could be positive (increased nectar) or negative (out-of-season host plants that could disrupt migration), or both. The monarch butterfly is an especially good target for this research because of its distinct migratory phases, the importance of hurricane-impacted zones to its annual cycle, and the large quantity of data available through an extensive network of citizen science programs.

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 High Survivorship of First-Generation Monarch Butterfly Eggs to Third Instar Associated with a Diverse Arthropod Community

Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 567
Author(s):  
Misty Stevenson ◽  
Kalynn L. Hudman ◽  
Alyx Scott ◽  
Kelsey Contreras ◽  
Jeffrey G. Kopachena
Keyword(s):  
Host Plants ◽  
First Generation ◽  
Danaus Plexippus ◽  
Monarch Butterfly ◽  
Conservation Strategies ◽  
North Texas ◽  
Ecological Processes ◽  
Area Of Occupancy ◽  
Predator Abundance ◽  
A Site

Based on surveys of winter roost sites, the eastern migratory population of the monarch butterfly (Danaus plexippus) in North America appears to have declined in the last 20 years and this has prompted the implementation of numerous conservation strategies. However, there is little information on the survivorship of first-generation monarchs in the core area of occupancy in Texas, Oklahoma, and Louisiana where overwinter population recovery begins. The purpose of this study was to determine the survivorship of first-generation eggs to third instars at a site in north Texas and to evaluate host plant arthropods for their effect on survivorship. Survivorship to third instar averaged 13.4% and varied from 11.7% to 15.6% over three years. The host plants harbored 77 arthropod taxa, including 27 predatory taxa. Despite their abundance, neither predator abundance nor predator richness predicted monarch survival. However, host plants upon which monarchs survived often harbored higher numbers of non-predatory arthropod taxa and more individuals of non-predatory taxa. These results suggest that ecological processes may have buffered the effects of predators and improved monarch survival in our study. The creation of diverse functional arthropod communities should be considered for effective monarch conservation, particularly in southern latitudes.

scholarly journals Pretty Picky for a Generalist: Impacts of Toxicity and Nutritional Quality on Mantid Prey Processing

2017 ◽  
Vol 46 (3) ◽  
pp. 626-632 ◽  
Author(s):  
Jamie L. Rafter ◽  
Justin F. Vendettuoli ◽  
Liahna Gonda-King ◽  
Daniel Niesen ◽  
Navindra P. Seeram ◽  
...  
Keyword(s):  
C:N Ratio ◽  
Danaus Plexippus ◽  
Monarch Butterfly ◽  
The Body ◽  
Gut Contents ◽  
Corn Borers ◽  
Body Tissues ◽  
Heterogeneous Quality ◽  
Behavioral Trials

Abstract Prey have evolved a number of defenses against predation, and predators have developed means of countering these protective measures. Although caterpillars of the monarch butterfly,Danaus plexippus L., are defended by cardenolides sequestered from their host plants, the Chinese mantidTenodera sinensis Saussure guts the caterpillar before consuming the rest of the body. We hypothesized that this gutting behavior might be driven by the heterogeneous quality of prey tissue with respect to toxicity and/or nutrients. We conducted behavioral trials in which mantids were offered cardenolide-containing and cardenolide-freeD. plexippus caterpillars and butterflies. In addition, we fed mantids starved and unstarvedD. plexippus caterpillars from each cardenolide treatment and nontoxicOstrinia nubilalis Hübner caterpillars. These trials were coupled with elemental analysis of the gut and body tissues of bothD. plexippus caterpillars and corn borers. Cardenolides did not affect mantid behavior: mantids gutted both cardenolide-containing and cardenolide-free caterpillars. In contrast, mantids consumed bothO. nubilalis and starvedD. plexippus caterpillars entirely.Danaus plexippus body tissue has a lower C:N ratio than their gut contents, whileO. nubilalis have similar ratios; gutting may reflect the mantid’s ability to regulate nutrient uptake. Our results suggest that post-capture prey processing by mantids is likely driven by a sophisticated assessment of resource quality.

scholarly journals Cardenolides, toxicity, and the costs of sequestration in the coevolutionary interaction between monarchs and milkweeds

2021 ◽  
Vol 118 (16) ◽  
pp. e2024463118
Author(s):  
Anurag A. Agrawal ◽  
Katalin Böröczky ◽  
Meena Haribal ◽  
Amy P. Hastings ◽  
Ronald A. White ◽  
...  
Keyword(s):  
Danaus Plexippus ◽  
Monarch Butterfly ◽  
Chemical Defenses ◽  
Trade Off ◽  
Asclepias Curassavica ◽  
Plant Chemical ◽  
Whole Plants ◽  
Benefits And Costs

For highly specialized insect herbivores, plant chemical defenses are often co-opted as cues for oviposition and sequestration. In such interactions, can plants evolve novel defenses, pushing herbivores to trade off benefits of specialization with costs of coping with toxins? We tested how variation in milkweed toxins (cardenolides) impacted monarch butterfly (Danaus plexippus) growth, sequestration, and oviposition when consuming tropical milkweed (Asclepias curassavica), one of two critical host plants worldwide. The most abundant leaf toxin, highly apolar and thiazolidine ring–containing voruscharin, accounted for 40% of leaf cardenolides, negatively predicted caterpillar growth, and was not sequestered. Using whole plants and purified voruscharin, we show that monarch caterpillars convert voruscharin to calotropin and calactin in vivo, imposing a burden on growth. As shown by in vitro experiments, this conversion is facilitated by temperature and alkaline pH. We next employed toxin-target site experiments with isolated cardenolides and the monarch’s neural Na+/K+-ATPase, revealing that voruscharin is highly inhibitory compared with several standards and sequestered cardenolides. The monarch’s typical >50-fold enhanced resistance to cardenolides compared with sensitive animals was absent for voruscharin, suggesting highly specific plant defense. Finally, oviposition was greatest on intermediate cardenolide plants, supporting the notion of a trade-off between benefits and costs of sequestration for this highly specialized herbivore. There is apparently ample opportunity for continued coevolution between monarchs and milkweeds, although the diffuse nature of the interaction, due to migration and interaction with multiple milkweeds, may limit the ability of monarchs to counteradapt.

Conservation of the Swift Parrot Lathamus discolor ? management lessons for a threatened migratory species

2007 ◽  
Vol 13 (2) ◽  
pp. 111 ◽  
Author(s):  
Debbie Saunders ◽  
Raymond Brereton ◽  
Chris Tzaros ◽  
Mark Holdsworth ◽  
Rob Price
Keyword(s):  
Site Fidelity ◽  
Bird Species ◽  
Migratory Bird ◽  
Small Population ◽  
Assessment Process ◽  
Migratory Species ◽  
Conservation Assessment ◽  
Broad Distribution ◽  
Large Numbers

Conserving habitat for wide-ranging fauna species provides a challenge because impacts on these species tend to be dismissed based on the assumption that there is sufficient habitat in other areas of its range. This incremental loss of habitat is a serious conservation issue for a diversity of bird species. As knowledge of wide-ranging and migratory bird species increases, it often becomes evident that they select specific sites on a regular basis (i.e., the species exhibit site fidelity). Gaining a better understanding of site fidelity and selective habitat use for wide-ranging species is clearly important, but also extremely challenging. In this paper, challenges associated with conservation of the migratory and wide-ranging Swift Parrot Lathamus discolor are discussed as an example of how a recovery programme has aimed to address such conservation and management challenges. Despite the small population size (less than 2 500 birds), broad distribution (1 250 000 km2) and often cryptic nature, the implementation of the national recovery programme has been successful in the identification and protection of important habitats. This has been made possible by involving large numbers of volunteers who collect long-term sighting and habitat data over large areas, together with more detailed ecological research. This information is then used to inform the conservation assessment process and to improve habitat conservation throughout the range of the species.

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
Keyword(s):  
Danaus Plexippus ◽  
Monarch Butterfly ◽  
The United States ◽  
Field Observations ◽  
Primary Host ◽  
The Past ◽  
Conservation Concern ◽  
Neonate Larvae ◽  
Choice Feeding ◽  
Predator Community

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.

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