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1.
Haisun Zhu Robert J Gegear Amy Casselman Sriramana Kanginakudru Steven M Reppert 《BMC biology》2009,7(1):14-14
Background
In the fall, Eastern North American monarch butterflies (Danaus plexippus) undergo a magnificent long-range migration. In contrast to spring and summer butterflies, fall migrants are juvenile hormone deficient, which leads to reproductive arrest and increased longevity. Migrants also use a time-compensated sun compass to help them navigate in the south/southwesterly direction en route for Mexico. Central issues in this area are defining the relationship between juvenile hormone status and oriented flight, critical features that differentiate summer monarchs from fall migrants, and identifying molecular correlates of behavioral state. 相似文献2.
3.
We present the draft 273 Mb genome of the migratory monarch butterfly (Danaus plexippus) and a set of 16,866 protein-coding genes. Orthology properties suggest that the Lepidoptera are the fastest evolving insect order yet examined. Compared to the silkmoth Bombyx mori, the monarch genome shares prominent similarity in orthology content, microsynteny, and protein family sizes. The monarch genome reveals a vertebrate-like opsin whose existence in insects is widespread; a full repertoire of molecular components for the monarch circadian clockwork; all members of the juvenile hormone biosynthetic pathway whose regulation shows unexpected sexual dimorphism; additional molecular signatures of oriented flight behavior; microRNAs that are differentially expressed between summer and migratory butterflies; monarch-specific expansions of chemoreceptors potentially important for long-distance migration; and a variant of the sodium/potassium pump that underlies a valuable chemical defense mechanism. The monarch genome enhances our ability to better understand the genetic and molecular basis of long-distance migration. 相似文献
4.
DAVID G. JAMES 《Ecological Entomology》1984,9(4):421-428
Abstract. 1. In the Sydney area of New South Wales, dry weights of reproductive monarch butterflies averaged 156 mg and were higher during winter than in other seasons. Dry weights of non-reproductive monarchs ranged from 216 to 324 mg and declined by 15–25% during over wintering.
2. Fat in reproductive butterflies ranged from 0.009 to 0.017g/0.1g dry weight and was lower during winter than in other seasons. Fat content of non-reproductive monarchs was higher (0.019–0.037 g/0.1g) and declined by 24–51% during over wintering.
3. Lean dry weights of reproductive monarchs were lower than those of non-reproductive individuals. Lean dry weights of non-reproductive butterflies increased rapidly at the beginning of over wintering and remained high throughout the winter. Analysis of protein content indicated the higher lean weight of non-reproductive monarchs was due to greater protein levels.
4. Moisture content of monarchs did not vary with season or reproductive status and appeared to be correlated with ambient humidity.
5. Non-reproductive monarch butterflies in New South Wales adjust bio chemically during over wintering. Energy reserve dynamics of these butterflies are comparable to those that occur in non-reproductive monarchs in North America. 相似文献
2. Fat in reproductive butterflies ranged from 0.009 to 0.017g/0.1g dry weight and was lower during winter than in other seasons. Fat content of non-reproductive monarchs was higher (0.019–0.037 g/0.1g) and declined by 24–51% during over wintering.
3. Lean dry weights of reproductive monarchs were lower than those of non-reproductive individuals. Lean dry weights of non-reproductive butterflies increased rapidly at the beginning of over wintering and remained high throughout the winter. Analysis of protein content indicated the higher lean weight of non-reproductive monarchs was due to greater protein levels.
4. Moisture content of monarchs did not vary with season or reproductive status and appeared to be correlated with ambient humidity.
5. Non-reproductive monarch butterflies in New South Wales adjust bio chemically during over wintering. Energy reserve dynamics of these butterflies are comparable to those that occur in non-reproductive monarchs in North America. 相似文献
5.
Four physiological parameters (haemolymph-juvenile hormone titre, protein concentration, vitellogenin concentration, and pharyngeal gland dry weight) were examined in the following categories of queenright adult worker bees: summer bees 1–40 days old, winter bees 80–130 days old, 12–100-day old bees at the beginning of winter, 100–195-day old bees at the end of winter, and 1–100-day old bees experimentally induced to live longer in summer.In contrast to the continuously increasing titre of juvenile hormone in ageing summer bees, winter bees kept a constant low level. In bees at the beginning of winter, the hormone titre never reached high values. However, at the end of winter it rose from a low to a high level, comparable with the high titre of 24–40-day old summer bees. In experimentally induced longlived bees in summer, the juvenile hormone titre did not increase as in normal summer bees but remained low as in bees at the beginning of winter. Among the known natural juvenile hormones, only juvenile hormone III was present in the haemolymph of winter bees.The results support the hypothesis of polyphenism being regulated by the titre of juvenile hormone in the haemolymph. 相似文献
6.
Constantí Stefanescu 《Ecological Entomology》2001,26(5):525-536
1. The migrant Vanessa atalanta (L.) occurs throughout Europe and North Africa. In autumn, populations emigrate from northern and central Europe to the Mediterranean region to overwinter. In the spring, the northern range is recolonised by migrants from the south. The dynamics of the species in the winter range is poorly known. 2. From 1994 to 1999, adults and immatures of V. atalanta were monitored all year round in Mediterranean habitats in north‐east Spain. 3. Data showed that the Catalonia lowlands is an area to which V. atalanta migrates to breed during the winter. Migrants arrive in October and early November and initiate a period of intensive breeding. Larval development occurs throughout the winter until a first annual generation of adults appears in early spring. 4. Most of the butterflies emerging in the spring emigrate and leave the area without breeding. The data suggest strongly that recolonisation of the northern range is by these butterflies not by wintering adults. Altitudinal migration also seems to be a common phenomenon, allowing a further summer generation of adults to occur at high elevations within the Mediterranean region. 5. The complex phenology of V. atalanta in its southern range has evolved as a strategy to track larval resources through space and time. Autumn migration coincides with the greatest availability of the main food plant, Urtica dioica L. Late spring migration occurs by the time food quality is decreasing. 相似文献
7.
Local and cross‐seasonal associations of climate and land use with abundance of monarch butterflies Danaus plexippus
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Sarah P. Saunders Leslie Ries Karen S. Oberhauser Wayne E. Thogmartin Elise F. Zipkin 《Ecography》2018,41(2):278-290
Quantifying how climate and land use factors drive population dynamics at regional scales is complex because it depends on the extent of spatial and temporal synchrony among local populations, and the integration of population processes throughout a species’ annual cycle. We modeled weekly, site‐specific summer abundance (1994–2013) of monarch butterflies Danaus plexippus at sites across Illinois, USA to assess relative associations of monarch abundance with climate and land use variables during the winter, spring, and summer stages of their annual cycle. We developed negative binomial regression models to estimate monarch abundance during recruitment in Illinois as a function of local climate, site‐specific crop cover, and county‐level herbicide (glyphosate) application. We also incorporated cross‐seasonal covariates, including annual abundance of wintering monarchs in Mexico and climate conditions during spring migration and breeding in Texas, USA. We provide the first empirical evidence of a negative association between county‐level glyphosate application and local abundance of adult monarchs, particularly in areas of concentrated agriculture. However, this association was only evident during the initial years of the adoption of herbicide‐resistant crops (1994–2003). We also found that wetter and, to a lesser degree, cooler springs in Texas were associated with higher summer abundances in Illinois, as were relatively cool local summer temperatures in Illinois. Site‐specific abundance of monarchs averaged approximately one fewer per site from 2004–2013 than during the previous decade, suggesting a recent decline in local abundance of monarch butterflies on their summer breeding grounds in Illinois. Our results demonstrate that seasonal climate and land use are associated with trends in adult monarch abundance, and our approach highlights the value of considering fine‐resolution temporal fluctuations in population‐level responses to environmental conditions when inferring the dynamics of migratory species. 相似文献
8.
Evidence for Partial Migration in the Southern Monarch Butterfly,Danaus erippus,in Bolivia and Argentina
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Migration is a common life‐history strategy that includes traits such as directed flight, increased wing size, seasonal lipid deposition and reproductive arrest. The degree of investment in these traits ultimately determines the life‐history strategy of individuals. Partial migration is a common mixed life‐history strategy where species or populations consist of both migrant and resident individuals. While this phenomenon is widespread across taxa, the ecological factors that select for and maintain partial migration are poorly understood, especially among insects. Here, we investigate regional life‐history traits associated with migration in the southern monarch, Danaus erippus, and describe a mixed life‐history strategy in this butterfly. Individuals from the Bolivian lowlands were observed throughout the year exhibiting mate‐ and milkweed‐directed behaviors. These butterflies had smaller wings, lower wing loads and maintained constant lipid and egg loads across summer and autumn months. Danaus erippus in the highlands of the Bolivian Andes were observed only in the summer and autumn months, during which they also showed mate‐ and milkweed‐directed behaviors. These individuals possessed similar‐sized wings and maintained similar lipid and egg loads as the lowland butterflies. In contrast, individuals from northwest Argentina showed persistent, directed, southwesterly flight during the autumn (March–May), larger wing size, higher wing loads, and increased autumn lipid deposition along with decreased egg production. These data indicate that D. erippus utilizes a mixed life‐history strategy with a combination of residents and migrants in the Bolivian lowlands, elevational migrants in the Bolivian Andes, and latitudinal migrants in northwestern Argentina. 相似文献
9.
Wm.S. Herman 《Journal of insect physiology》1973,19(9):1883-1887
Monarch butterflies (Danaus plexippus) collected during winter in central California are reproductively inactive. Oögenesis is stimulated in such animals by environments simulating summer conditions. Allatectomized or neck-ligatured winter animals do not normally undergo oögenesis when placed in summer conditions, but apparently normal oögenesis occurs if they are injected with juvenile hormone isomers. Injections of such isomers into winter animals held in environments simulating winter also promote oögenesis, even though winter conditions typically inhibit ovarian development. Reproductive dormany in winter Monarchs of central California therefore appears to be due (at least partially) to environmentally induced inactivity of the corpora allata. 相似文献
10.
ABSTRACT. Female monarch butterflies, Danaus plexippus (L.) were collected from clusters in the Sydney region at weekly intervals after cluster formation. They were neck-ligated and injected with juvenile hormone (JH) in order to test for any period of lowered JH sensitivity during the non-reproductive clustering phase. Response was assessed by production of mature oocytes. In all weekly samples, the mean response was equal to or greater than that of newly emerged females reared and maintained in optimal conditions, and was substantially higher than that reported for diapausing monarchs in North American clusters. The result is further evidence for the absence of a true reproductive diapause in New South Wales populations. 相似文献
11.
Effects of the juvenile hormone mimic pyriproxyfen on female reproduction and longevity in the butterfly Bicyclus anynana 总被引:1,自引:0,他引:1
Female Bicyclus anynana butterflies given pyriproxyfen, a mimic of juvenile hormone, exhibited increased egg‐laying rates and early fecundity, but reduced longevity compared with control animals. Thus, pyriproxyfen application yielded antagonistic effects on different components of fitness, possibly demonstrating a juvenile hormone‐mediated trade‐off between present and future reproduction. Lifetime fecundity and egg size, however, showed no consistent response to pyriproxyfen, with lifetime fecundity being increased or decreased and egg size being reduced in one out of four experiments only. Females were most sensitive to pyriproxyfen around the onset of oviposition, coinciding with naturally increasing juvenile hormone titers in other Lepidoptera. Amounts between 1 and 10 µg pyriproxyfen were found to be effective, with, however, pronounced differences among experiments. This is attributed to differences in assay conditions. High pyriproxyfen concentrations (100 µg) as well as repeated applications of smaller amounts did not affect reproductive traits, but tended to reduce longevity. 相似文献
12.
Lyons JI Pierce AA Barribeau SM Sternberg ED Mongue AJ De Roode JC 《Molecular ecology》2012,21(14):3433-3444
Monarch butterflies are best known for their spectacular annual migration from eastern North America to Mexico. Monarchs also occur in the North American states west of the Rocky Mountains, from where they fly shorter distances to the California Coast. Whether eastern and western North American monarchs form one genetic population or are genetically differentiated remains hotly debated, and resolution of this debate is essential to understand monarch migration patterns and to protect this iconic insect species. We studied the genetic structure of North American migratory monarch populations, as well as nonmigratory populations in Hawaii and New Zealand. Our results show that eastern and western migratory monarchs form one admixed population and that monarchs from Hawaii and New Zealand have genetically diverged from North American butterflies. These findings suggest that eastern and western monarch butterflies maintain their divergent migrations despite genetic mixing. The finding that eastern and western monarchs form one genetic population also suggests that the conservation of overwintering sites in Mexico is crucial for the protection of monarchs in both eastern and western North America. 相似文献
13.
W. U. Blanckenhorn 《Oecologia》1994,97(3):354-365
Using field and laboratory observations and experiments over 3 years, I investigated whether reproductive trade-offs shape individual life histories in two natural populations of the water strider, Aquarius remigis, in which univoltine and bivoltine life cycles coexist. Both later eclosion dates and food shortages, even after adult eclosion, induced diapause in females, thus deferring reproduction to the following spring. Adult body size was positively affected by food availability during juvenile development. Higher food levels also increased the reproductive output of females, but not their longevity or oviposition period. When compared to spring breeders (univoltine life cycle), direct (summer) breeders (bivoltine life cycle) experienced reduced lifetime egg numbers and longevity, as well as reduced survivorship of their second-summer-generation offspring; these reproductive costs offset, at least in part, the advantage in non-decreasing populations of having two generations per year. Fecundity was correlated with body size, and among summer-generation females direct breeders were larger than non-breeders. The time remaining before the onset of winter and/or the time since adult eclosion augmented cumulative energy uptake, and consequently the lipid reserves and winter survival probability of non-breeding (diapausing) summer adults approaching hibernation. Overwintered spring reproductives died at faster rates than non-reproductive summer individuals despite greater food availability in spring, indicating a mortality cost of reproduction. Body length correlated with absolute and not with proportional lipid content but showed no consistent relationship with survivorship in the field. These results are in agreement with current theory on the evolution of insect voltinism patterns, and further indicate high degrees of life history flexibility (phenotypic plasticity) in the study populations in response to variable environmental factors (notably photoperiod and food availability). This may be related to their location in a geographic transition zone from uni- to bivoltine life cycles. 相似文献
14.
Sonia Altizer Keith A. Hobson Andrew K. Davis Jacobus C. De Roode Leonard I. Wassenaar 《PloS one》2015,10(11)
Long-distance migration can lower parasite prevalence if strenuous journeys remove infected animals from wild populations. We examined wild monarch butterflies (Danaus plexippus) to investigate the potential costs of the protozoan Ophryocystis elektroscirrha on migratory success. We collected monarchs from two wintering sites in central Mexico to compare infection status with hydrogen isotope (δ
2H) measurements as an indicator of latitude of origin at the start of fall migration. On average, uninfected monarchs had lower δ
2H values than parasitized butterflies, indicating that uninfected butterflies originated from more northerly latitudes and travelled farther distances to reach Mexico. Within the infected class, monarchs with higher quantitative spore loads originated from more southerly latitudes, indicating that heavily infected monarchs originating from farther north are less likely to reach Mexico. We ruled out the alternative explanation that lower latitudes give rise to more infected monarchs prior to the onset of migration using citizen science data to examine regional differences in parasite prevalence during the summer breeding season. We also found a positive association between monarch wing area and estimated distance flown. Collectively, these results emphasize that seasonal migrations can help lower infection levels in wild animal populations. Our findings, combined with recent declines in the numbers of migratory monarchs wintering in Mexico and observations of sedentary (winter breeding) monarch populations in the southern U.S., suggest that shifts from migratory to sedentary behavior will likely lead to greater infection prevalence for North American monarchs. 相似文献
15.
Elise F. Zipkin Leslie Ries Rick Reeves James Regetz Karen S. Oberhauser 《Global Change Biology》2012,18(10):3039-3049
Understanding the impacts of climate on migratory species is complicated by the fact that these species travel through several climates that may be changing in diverse ways throughout their complete migratory cycle. Most studies are not designed to tease out the direct and indirect effects of climate at various stages along the migration route. We assess the impacts of spring and summer climate conditions on breeding monarch butterflies, a species that completes its annual migration cycle over several generations. No single, broad‐scale climate metric can explain summer breeding phenology or the substantial year‐to‐year fluctuations observed in population abundances. As such, we built a Poisson regression model to help explain annual arrival times and abundances in the Midwestern United States. We incorporated the climate conditions experienced both during a spring migration/breeding phase in Texas as well as during subsequent arrival and breeding during the main recruitment period in Ohio. Using data from a state‐wide butterfly monitoring network in Ohio, our results suggest that climate acts in conflicting ways during the spring and summer seasons. High spring precipitation in Texas is associated with the largest annual population growth in Ohio and the earliest arrival to the summer breeding ground, as are intermediate spring temperatures in Texas. On the other hand, the timing of monarch arrivals to the summer breeding grounds is not affected by climate conditions within Ohio. Once in Ohio for summer breeding, precipitation has minimal impacts on overall abundances, whereas warmer summer temperatures are generally associated with the highest expected abundances, yet this effect is mitigated by the average seasonal temperature of each location in that the warmest sites receive no benefit of above average summer temperatures. Our results highlight the complex relationship between climate and performance for a migrating species and suggest that attempts to understand how monarchs will be affected by future climate conditions will be challenging. 相似文献
16.
Optimal posteclosion ovarian development in monarch butterflies occurs at about 28°C. Higher and lower temperatures appear progressively inhibitory. Reproductive gland development in males follows a similar pattern. Juvenile hormone injections stimulate oöcyte maturation in animals held at 20 and 35°C but are most effective at the higher temperature. Juvenile hormone injections are ineffective at 10 and 15°C. The stimulatory effect of increasing photophase on ovarian development was most apparent at optimal temperature. The possible significance of our findings to monarch migration is discussed. 相似文献
17.
Monarch butterflies (Danaus plexippus) depend on the presence of host plants (Asclepias spp.) within their breeding range for reproduction. In the southern Great Plains, Asclepias viridis is a perennial that flowers in May and June, and starts to senesce by August. It is locally abundant and readily used by monarchs as a host plant. We evaluated the effects of summer prescribed fire on A. viridis and the use of A. viridis by monarch butterflies. Summer prescribed fire generated a newly emergent population of A. viridis that was absent in other areas. Pre-migrant monarch butterflies laid eggs on A. viridis in summer burned plots in late August and September, allowing adequate time for a new generation of adult monarchs to emerge and migrate south to their overwintering grounds. Thus, summer prescribed fire may provide host plant patches and/or corridors for pre-migrant monarchs during a time when host plant availability may be limited in other areas. 相似文献
18.
Surviving inhospitable periods or seasons may greatly affect fitness. Evidence of this exists in the prevalence of dormant stages in the life cycles of most insects. Here I focused on butterflies with distinct seasonal morphological types (not a genetic polymorphism) in which one morphological type, or form, delays reproduction until favorable conditions return, while the other form develops in an environment that favors direct reproduction. For two butterflies, Anaea aidea and A. andria, I tested the hypothesis that the development of each seasonal form involves a differential allocation of resources to survival at eclosion. I assayed differences in adult longevity among summer and winter forms in either a warm, active environment or a cool, calm environment. Winter form adults lived 40 times longer than summer form but only in calm, cool conditions. The magnitude of this difference provided compelling evidence that the winter form body plan and metabolic strategy (i.e. resource conservatism) favor long term survival. This research suggests that winter form adults maintain lowered metabolic rate, a common feature of diapause, to conserve resources and delay senescence while overwintering. 相似文献
19.
Eastern North American monarch butterflies (Danaus plexippus L.) show a series of range shifts during their breeding season. Using ecological niche modeling, we studied the environmental context of these shifts by identifying the ecological conditions that monarchs use in successive summer months. Monarchs use a consistent ecological regimen through the summer, but these conditions contrast strikingly with those used during the winter. Hence, monarchs exhibit niche-following among sequential breeding generations but niche-switching between the breeding and overwintering stages of their annual cycle. We projected their breeding ecological niche onto monthly future climate scenarios, which indicated northward shifts, particularly at the northern extreme of their summer movements, over the next 50 yrs; if both monarchs and their milkweed host plants cannot track these changing climates, monarchs could lose distributional area during critical breeding months. 相似文献
20.
Previous research on Monarch butterflies has shown that juvenile hormone (JH) stimulates the development of the ovary and certain reproductive glands of both sexes. Ecdysterone injections into intact Monarchs demonstrate that low doses of this hormone inhibit ovarian development, and higher doses stimulate the male and female reproductive glands. In addition, experiments using neckligatured adults show that ecdysterone stimulates the reproductive glands of both sexes, in the apparent absence of JH, with the most pronounced effect being observed on the female colleterial gland. Other studies with neck-ligatured animals demonstrate that ecdysterone also synergizes with JH on the female gland and all three male glands. The feasibility of using Monarch reproductive glands for studies on the mode of action and interaction of JH and ecdysterone, and the possibility of a rôle of ecdysterone in the normal regulation of Monarch oögenesis, are discussed. 相似文献