scholarly journals To quiver or to shiver: increased melanization benefits thermoregulation, but reduces warning signal efficacy in the wood tiger moth

2013 ◽  
Vol 280 (1755) ◽  
pp. 20122812 ◽  
Author(s):  
Robert H. Hegna ◽  
Ossi Nokelainen ◽  
Jonathan R. Hegna ◽  
Johanna Mappes
Keyword(s):  
Field Experiments ◽  
Warning Signal ◽  
Cold Temperatures ◽  
Signal Efficacy ◽  
Extensive Field ◽  
Tiger Moth ◽  
Thermal Measurements ◽  
Selective Forces ◽  
Parasemia Plantaginis ◽  
Tiger Moths

Melanin production is often considered costly, yet beneficial for thermoregulation. Studies of variation in melanization and the opposing selective forces that underlie its variability contribute greatly to understanding natural selection. We investigated whether melanization benefits are traded off with predation risk to promote observed local and geographical variation in the warning signal of adult male wood tiger moths ( Parasemia plantaginis ). Warning signal variation is predicted to reduce survival in aposematic species. However, in P. plantaginis , male hindwings are either yellow or white in Europe, and show continuous variation in melanized markings that cover 20 to 90 per cent of the hindwing. We found that the amount of melanization increased from 40 to 59 per cent between Estonia (58° N) and north Finland (67° N), suggesting melanization carries thermoregulatory benefits. Our thermal measurements showed that more melanic individuals warmed up more quickly on average than less melanic individuals, which probably benefits flight in cold temperatures. With extensive field experiments in central Finland and the Alpine region, we found that more melanic individuals suffered increased predation. Together, our data suggest that warning signal efficiency is constrained by thermoregulatory benefits. Differences in relative costs and benefits of melanin probably help to maintain the geographical warning signal differences.

scholarly journals Trade-off between warning signal efficacy and mating success in the wood tiger moth

2011 ◽  
Vol 279 (1727) ◽  
pp. 257-265 ◽  
Author(s):  
Ossi Nokelainen ◽  
Robert H. Hegna ◽  
Joanneke H. Reudler ◽  
Carita Lindstedt ◽  
Johanna Mappes
Keyword(s):  
Mating Success ◽  
Warning Signal ◽  
Trade Off ◽  
White Males ◽  
Survival Selection ◽  
Signal Efficacy ◽  
Trade Offs ◽  
Tiger Moth ◽  
Sexual Signalling ◽  
Colour Morphs

The coloration of species can have multiple functions, such as predator avoidance and sexual signalling, that directly affect fitness. As selection should favour traits that positively affect fitness, the genes underlying the trait should reach fixation, thereby preventing the evolution of polymorphisms. This is particularly true for aposematic species that rely on coloration as a warning signal to advertise their unprofitability to predators. Nonetheless, there are numerous examples of aposematic species showing remarkable colour polymorphisms. We examined whether colour polymorphism in the wood tiger moth is maintained by trade-offs between different functions of coloration. In Finland, males of this species have two distinct colour morphs: white and yellow. The efficacy of the warning signal of these morphs was tested by offering them to blue tits in the laboratory. Birds hesitated significantly longer to attack yellow than white males. In a field experiment, the survival of the yellow males was also higher than white males. However, mating experiments in the laboratory revealed that yellow males had lower mating success than white males. Our results offer an explanation for the maintenance of polymorphism via trade-off between survival selection and mating success.

Temporal relationship between genetic and warning signal variation in the aposematic wood tiger moth (Parasemia plantaginis)

2014 ◽  
Vol 23 (20) ◽  
pp. 4939-4957 ◽  
Author(s):  
Juan A. Galarza ◽  
Ossi Nokelainen ◽  
Roghaeih Ashrafi ◽  
Robert H. Hegna ◽  
Johanna Mappes
Keyword(s):  
Temporal Relationship ◽  
Warning Signal ◽  
Signal Variation ◽  
Tiger Moth ◽  
Parasemia Plantaginis

scholarly journals Frequency-dependent flight activity in the colour polymorphic wood tiger moth

2015 ◽  
Vol 61 (4) ◽  
pp. 765-772 ◽  
Author(s):  
Bibiana Rojas ◽  
Armando Luis-MartÍnez ◽  
Johanna Mappes
Keyword(s):  
Warning Signal ◽  
Flight Activity ◽  
Natural Environments ◽  
Frequency Dependent ◽  
Sustained Activity ◽  
White Males ◽  
Tiger Moth ◽  
Parasemia Plantaginis ◽  
Potential Frequency

Abstract Predators efficiently learn to avoid one type of warning signal rather than several, making colour polymorphisms unexpected. Aposematic wood tiger moth males Parasemia plantaginis have either white or yellow hindwing coloration across Europe. Previous studies indicate that yellow males are better defended from predators, while white males have a positively frequency-dependent mating advantage. However, the potential frequency-dependent behavioural differences in flight between the morphs, as well as the role of male-male interactions in inducing flying activity, have not been previously considered. We ran an outdoor cage experiment where proportions of both male morphs were manipulated to test whether flying activity was frequencydependent and differed between morphs. The white morph was significantly more active than the yellow one across all treatments, and sustained activity for longer. Overall activity for both morphs was considerably lower in the yellow-biased environment, suggesting that higher proportions of yellow males in a population may lead to overall reduced flying activity. The activity of the yellow morph also followed a steeper, narrower curve than that of the white morph during peak female calling activity. We suggest that white males, with their presumably less costly defences, have more resources to invest in flight for predator escape and finding mates. Yellow males, which are better protected but less sexually selected, may instead compensate their lower flight activity by ‘flying smart’ during the peak female-calling periods. Thus, both morphs may be able to behaviourally balance the trade-off between warning signal selection and sexual selection. Our results emphasize the greater need to investigate animal behaviour and colour polymorphisms in natural or semi-natural environments.

scholarly journals Predator-Induced Plasticity on Warning Signal and Larval Life-History Traits of the Aposematic Wood Tiger Moth, Arctia plantaginis

2021 ◽  
Vol 9 ◽  
Author(s):  
Diana Abondano Almeida ◽  
Johanna Mappes ◽  
Swanne Gordon
Keyword(s):  
Life History ◽  
Predation Risk ◽  
Life Histories ◽  
Development Time ◽  
Life History Traits ◽  
Environmental Changes ◽  
Warning Signal ◽  
Black Body ◽  
Tiger Moth ◽  
Tiger Moths

Predator-induced plasticity in life-history and antipredator traits during the larval period has been extensively studied in organisms with complex life-histories. However, it is unclear whether different levels of predation could induce warning signals in aposematic organisms. Here, we investigated whether predator-simulated handling affects warning coloration and life-history traits in the aposematic wood tiger moth larva, Arctia plantaginis. As juveniles, a larger orange patch on an otherwise black body signifies a more efficient warning signal against predators but this comes at the costs of conspicuousness and thermoregulation. Given this, one would expect that an increase in predation risk would induce flexible expression of the orange patch. Prior research in this system points to plastic effects being important as a response to environmental changes for life history traits, but we had yet to assess whether this was the case for predation risk, a key driver of this species evolution. Using a full-sib rearing design, in which individuals were reared in the presence and absence of a non-lethal simulated bird attack, we evaluated flexible responses of warning signal size (number of orange segments), growth, molting events, and development time in wood tiger moths. All measured traits except development time showed a significant response to predation. Larvae from the predation treatment developed a more melanized warning signal (smaller orange patch), reached a smaller body size, and molted more often. Our results suggest plasticity is indeed important in aposematic organisms, but in this case may be complicated by the trade-off between costly pigmentation and other life-history traits.

Relative contributions of light interception and radiation use efficiency to the reduction of maize productivity under cold temperatures

2008 ◽  
Vol 35 (10) ◽  
pp. 885 ◽  
Author(s):  
Gaëtan Louarn ◽  
Karine Chenu ◽  
Christian Fournier ◽  
Bruno Andrieu ◽  
Catherine Giauffret
Keyword(s):  
Field Experiments ◽  
Light Interception ◽  
Leaf Length ◽  
Radiation Use Efficiency ◽  
Model Assessment ◽  
Cold Temperatures ◽  
Maize Productivity ◽  
Cold Tolerant ◽  
Use Efficiency ◽  
Radiation Use

Maize (Zea mays L.) is a chill-susceptible crop cultivated in northern latitude environments. The detrimental effects of cold on growth and photosynthetic activity have long been established. However, a general overview of how important these processes are with respect to the reduction of productivity reported in the field is still lacking. In this study, a model-assisted approach was used to dissect variations in productivity under suboptimal temperatures and quantify the relative contributions of light interception (PARc) and radiation use efficiency (RUE) from emergence to flowering. A combination of architectural and light transfer models was used to calculate light interception in three field experiments with two cold-tolerant lines and at two sowing dates. Model assessment confirmed that the approach was suitable to infer light interception. Biomass production was strongly affected by early sowings. RUE was identified as the main cause of biomass reduction during cold events. Furthermore, PARc explained most of the variability observed at flowering, its relative contributions being more or less important according to the climate experienced. Cold temperatures resulted in lower PARc, mainly because final leaf length and width were significantly reduced for all leaves emerging after the first cold occurrence. These results confirm that virtual plants can be useful as fine phenotyping tools. A scheme of action of cold on leaf expansion, light interception and radiation use efficiency is discussed with a view towards helping breeders define relevant selection criteria.

scholarly journals Adding Epidemiologically Important Meteorological Data to Peanut Rx, the Risk Assessment Framework for Spotted Wilt of Peanut

2020 ◽  
Vol 110 (6) ◽  
pp. 1199-1207 ◽  
Author(s):  
Thomas M. Chappell ◽  
Clarence B. Codod ◽  
Blake W. Williams ◽  
Robert C. Kemerait ◽  
Albert K. Culbreath ◽  
...  
Keyword(s):  
Risk Factors ◽  
Field Experiments ◽  
Meteorological Data ◽  
Field Research ◽  
Point System ◽  
Tomato Spotted Wilt ◽  
Extensive Field ◽  
Associated Risk Factors ◽  
Grower Survey ◽  
Wilt Virus

Management of disease affecting peanut in the southeastern United States has benefited from extensive field research identifying disease-associated risk factors since the 1990s. An assessment of risk factors associated with tomato spotted wilt (TSW), caused by tomato spotted wilt virus and spread exclusively by thrips, is available to growers through Peanut Rx, a tool developed to inform peanut management decisions. Peanut Rx provides an assessment of relative TSW risk as an index. The assessment provides information about the relative degree to which a field characterized by a specified suite of practices is at risk of crop loss caused by TSW. Loss results when infection occurs, and infection rates are determined, in part, by factors outside a grower’s control, primarily the abundance of dispersing, viruliferous thrips. In this study, we incorporated meteorological variables useful for predicting thrips dispersal, increasing the robustness of the Peanut Rx framework in relation to variation in the weather. We used data from field experiments and a large grower survey to estimate the relationships between weather and TSW risk mediated by thrips vectors, and developed an addition to Peanut Rx that proved informative and easy to implement. The expected temporal occurrence of major thrips flights, as a function of heat and precipitation, was translated into the existing risk-point system of Peanut Rx. Results from the grower survey further demonstrated the validity of Peanut Rx for guiding growers’ decisions to minimize risk of TSW.

Warning Signal Efficacy: Assessing the Effects of Color, Iridescence, and Time of Day in the Field

Ethology ◽  
2015 ◽  
Vol 121 (9) ◽  
pp. 861-873 ◽  
Author(s):  
Kimberly V. Pegram ◽  
Hanh A. Han ◽  
Ronald L. Rutowski
Keyword(s):  
Warning Signal ◽  
Time Of Day ◽  
Signal Efficacy

First microsatellite panel for the Wood Tiger Moth (Parasemia plantaginis)

2010 ◽  
Vol 3 (2) ◽  
pp. 197-199 ◽  
Author(s):  
Juan A. Galarza ◽  
Sari M. Viinikainen ◽  
Roghaieh Ashrafi ◽  
Johanna Mappes
Keyword(s):  
Tiger Moth ◽  
Parasemia Plantaginis

Anti-bat flight activity in sound-producing versus silent moths

2008 ◽  
Vol 86 (6) ◽  
pp. 582-587 ◽  
Author(s):  
John M. Ratcliffe ◽  
Amanda R. Soutar ◽  
Katherine E. Muma ◽  
Cassandra Guignion ◽  
James H. Fullard
Keyword(s):  
Flight Time ◽  
Flight Activity ◽  
Echolocation Calls ◽  
Successful Reproduction ◽  
Tiger Moth ◽  
Moth Species ◽  
Presence And Absence ◽  
Tiger Moths ◽  
Palatable Species

The ultrasonic clicks produced by some tiger moths — all of which possess bat-detecting ears — are effective acoustic aposematic or mimetic signals, conferring protection against aerial hawking bats. Clicks are produced in response to bat echolocation calls. Palatable, silent non-tiger-moth species with bat-detecting ears fly away from distant bats and effect erratic flight maneuvers or stop flying in response to the calls of bats nearby. These flight responses are also an effective defense. We tested the hypotheses that sound-producing tiger moths (i) do not exhibit the reduction in flight time typical of silent, palatable moth species when presented with ultrasound simulating bat echolocation calls and (ii) exhibit more flight activity than silent, palatable species both in the presence and absence of ultrasound. We found that sound-producing tiger moths did not significantly reduce flight activity to bat-like sounds and that silent tiger moths and other noctuoid species did. We also found that sound-producing tiger moths flew significantly more than did silent species in both the presence and the absence of ultrasound. The benefits of acoustic aposematism may allow sound producers to spend more time aloft than silent species and thereby improve their chances of successful reproduction.

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