0000000000459851

AUTHOR

Kaisa Suisto

Ants Data from How to fight multiple enemies: target-specific chemical defences in an aposematic moth

Animals have evolved different defensive strategies to survive predation, among which chemical defences are particularly widespread and diverse. Here we investigate the function of chemical defence diversity, hypothesizing that such diversity has evolved as a response to multiple enemies. The aposematic wood tiger moth (Arctia plantaginis) displays conspicuous hindwing coloration and secretes distinct defensive fluids from their thoracic glands and abdomen. We presented the two defensive fluids from lab-reared moths to two biologically relevant predators, birds and ants, and measured their reaction in controlled bioassays (no information on colour was provided). We found that defensive flui…

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Defense against predators incurs high reproductive costs for the aposematic moth Arctia plantaginis

Abstract To understand how variation in warning displays evolves and is maintained, we need to understand not only how perceivers of these traits select color and toxicity but also the sources of the genetic and phenotypic variation exposed to selection by them. We studied these aspects in the wood tiger moth Arctia plantaginis, which has two locally co-occurring male color morphs in Europe: yellow and white. When threatened, both morphs produce defensive secretions from their abdomen and from thoracic glands. Abdominal fluid has shown to be more important against invertebrate predators than avian predators, and the defensive secretion of the yellow morph is more effective against ants. Her…

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Evaluating responses to temperature during pre-metamorphosis and carry-over effects at post-metamorphosis in the wood tiger moth (Arctia plantaginis)

Insect metamorphosis is one of the most recognized processes delimiting transitions between phenotypes. It has been traditionally postulated as an adaptive process decoupling traits between life stages, allowing evolutionary independence of pre- and post-metamorphic phenotypes. However, the degree of autonomy between these life stages varies depending on the species and has not been studied in detail over multiple traits simultaneously. Here, we reared full-sib larvae of the warningly coloured wood tiger moth ( Arctia plantaginis ) in different temperatures and examined their responses for phenotypic (melanization change, number of moults), gene expression (RNA-seq and qPCR of candidate ge…

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Supplementary Figures from Evaluating responses to temperature during pre-metamorphosis and carry-over effects at post-metamorphosis in the wood tiger moth (Arctia plantaginis)

Figures visualising statistical results

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Appearance before performance? : Nutritional constraints on life‐history traits, but not warning signal expression in aposematic moths

1.Trade‐offs have been shown to play an important role in the divergence of mating strategies and sexual ornamentation, but their importance in explaining warning signal diversity has received less attention. In aposematic organisms, allocation costs of producing the conspicuous warning signal pigmentation under nutritional stress could potentially trade‐off with life‐history traits and maintain variation in warning colouration. 2. We studied this with an aposematic herbivore Arctia plantaginis (Arctiidae), whose larvae and adults show extensive variation in aposematic colouration. In larvae, less melanic colouration (i.e. larger orange patterns) produces a more efficient warning signal aga…

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Heterozygote advantage and pleiotropy contribute to intraspecific color trait variability

The persistence of intrapopulation phenotypic variation typically requires some form of balancing selection because drift and directional selection eventually erode genetic variation. Heterozygote advantage remains a classic explanation for the maintenance of genetic variation in the face of selection. However, examples of heterozygote advantage, other than those associated with disease resistance, are rather uncommon. Across most of its distribution, males of the aposematic moth Arctia plantaginis have two hindwing phenotypes determined by a heritable one locus-two allele polymorphism (genotypes: WW/Wy = white morph, yy = yellow morph). Using genotyped moths, we show that the presence of o…

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How to fight multiple enemies : target-specific chemical defences in an aposematic moth

Animals have evolved different defensive strategies to survive predation, among which chemical defences are particularly widespread and diverse. Here we investigate the function of chemical defence diversity, hypothesizing that such diversity has evolved as a response to multiple enemies. The aposematic wood tiger moth (Arctia plantaginis) displays conspicuous hindwing coloration and secretes distinct defensive fluids from its thoracic glands and abdomen. We presented the two defensive fluids from laboratory-reared moths to two biologically relevant predators, birds and ants, and measured their reaction in controlled bioassays (no information on colour was provided). We found that defensive…

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Bird Data from How to fight multiple enemies: target-specific chemical defences in an aposematic moth

Animals have evolved different defensive strategies to survive predation, among which chemical defences are particularly widespread and diverse. Here we investigate the function of chemical defence diversity, hypothesizing that such diversity has evolved as a response to multiple enemies. The aposematic wood tiger moth (Arctia plantaginis) displays conspicuous hindwing coloration and secretes distinct defensive fluids from their thoracic glands and abdomen. We presented the two defensive fluids from lab-reared moths to two biologically relevant predators, birds and ants, and measured their reaction in controlled bioassays (no information on colour was provided). We found that defensive flui…

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GC/FT-IR Analysis of Novel 4,6,9-Triene and 2,4,6,9-Tetraene Occurring in a Female Pheromone Gland of Arctia plantaginis (Erebidae: Arctiinae)

Fifteen subspecies of the wood tiger moth, Arctia plantaginis (Lepidoptera: Erebidae: Arctiinae), have been recorded in the Northern Hemisphere. An analysis of crude pheromone extracts by GC equipped with an electroantennographic (EAG) detector showed four EAG-active components (Comps. I–IV) that were commonly involved in the pheromone glands of two subspecies inhabiting Japan and Finland. Comp. I is a major component (>75%) and the others are minor components (3% - 15%). Their mass spectra, measured by GC/MS, revealed the chemical structures of C21 unsaturated hydrocarbons as follows: 3,6,9-triene for Comp. I, 4,6,9-triene for Comp. II, 1,3,6,9-tetraene for Comp. III, and 2,4,6,9-tetraene …

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Genetic colour variation visible for predators and conspecifics is concealed from humans in a polymorphic moth

The definition of colour polymorphism is intuitive: genetic variants express discretely coloured phenotypes. This classification is, however, elusive as humans form subjective categories or ignore differences that cannot be seen by human eyes. We demonstrate an example of a 'cryptic morph' in a polymorphic wood tiger moth (Arctia plantaginis), a phenomenon that may be common among well-studied species. We used pedigree data from nearly 20,000 individuals to infer the inheritance of hindwing colouration. The evidence supports a single Mendelian locus with two alleles in males: WW and Wy produce the white and yy the yellow hindwing colour. The inheritance could not be resolved in females as t…

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Supplementary Methods and Results from How to fight multiple enemies: target-specific chemical defences in an aposematic moth

Supplementary methods and supplementary results

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Video from How to fight multiple enemies: target-specific chemical defences in an aposematic moth

Video in slow motion showing the reaction of a blue tit to the chemical defences of a wood tiger moth

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Data from: How to fight multiple enemies: target-specific chemical defences in an aposematic moth

Animals have evolved different defensive strategies to survive predation, among which chemical defences are particularly widespread and diverse. Here we investigate the function of chemical defence diversity, hypothesising that such diversity has evolved as a response to multiple enemies. The aposematic wood tiger moth (Arctia plantaginis) displays conspicuous hindwing colouration and secretes two distinct defensive fluids, from their thoracic glands and abdomen. We presented fluids from lab-reared moths to two biologically relevant predators, birds and ants, and measured their reaction in controlled bioassays (no information on colour was provided). We found that defensive fluids are targe…

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Supplementary tables from Evaluating responses to temperature during pre-metamorphosis and carry-over effects at post-metamorphosis in the wood tiger moth (Arctia plantaginis)

Details of statistical analyses

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Figure S4 from How to fight multiple enemies: target-specific chemical defences in an aposematic moth

Differences in composition between the ‘neck’ (a) and abdominal (b) fluids of wood tiger moths. Neck fluids have a richer chemical profile, with their main compounds being carboxylic acids (see Table II in Supplementary Material 5). Photos: Janne Valkonen.

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Figure S5 from How to fight multiple enemies: target-specific chemical defences in an aposematic moth

Bird (a, b) and ant (c) response to pure pyrazine. Birds ate fewer oats soaked with 2-sec-butyl-3-methoxypyrazine (a; both in a concentration of 1ng/µl (P) and 0.1ng/µl (Pb)). Also, they tended to have longer latencies to approach pyrazine-soaked oats (both concentrations pooled) than control oats (b). Ant response to 2-sec-butyl-3-methoxypyrazine was, in contrast, not different from that to the control sugar solution (c).

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Figure S3 from How to fight multiple enemies: target-specific chemical defences in an aposematic moth

Results of GC-MS analysis using Selected Ion Monitoring of ions 124, 138 and 151 of the neck fluid of a single moth. Top row shows total abundance of all three ions.

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