Data from: Not just the sum of its parts: Geographic variation and nonadditive effects of pyrazines in the chemical defence of an aposematic moth
Data files
Sep 25, 2024 version files 64.70 KB
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BirdsGeoFinControlJEB.txt
44.28 KB
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Pyrazines_Populations.txt
13.42 KB
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README.md
2.58 KB
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weight_LABmoths.txt
4.42 KB
Abstract
Chemical defences often vary within and between populations both in quantity and quality, which is puzzling if prey survival is dependent on the strength of the defence. We investigated the within- and between-population variability in chemical defence of the wood tiger moth (Arctia plantaginis). The major components of its defences, SBMP (2-sec-butyl-3-methoxypyrazine) and IBMP (2-isobutyl-3-methoxypyrazine), are volatiles that deter bird attacks. We hypothesised that 1) variation in the chemical defences of male wood tiger moths reflects the local predation pressure; 2) observed differences in quantity and quality of defence among populations have a genetic basis; and 3) increasing concentrations of SBMP and IBMP will elicit greater aversive reactions in predators, with the two pyrazines having an additive effect on predators’ avoidance. We found that 1) the chemical defence of wild moths partly reflects local predator selection: high predation pressure populations (Scotland and Georgia) had stronger chemical defences, but not lower variance, than the low-predation populations (Estonia and Finland). 2) Based on the common garden results, both genetic and environmental components seem to influence the strength of chemical defence in moth populations; and 3) IBMP alone did not provide protection against bird predators but worked against bird attacks only when combined with SBMP, and while SBMP was more effective at higher concentrations, IBMP was not. Altogether this suggests that, when it comes to pyrazine concentration, more is not always better, highlighting the importance of testing the efficacy of chemical defence and its components with relevant predators, as extrapolating from chemical data may be less than straightforward.
README: Not just the sum of its parts: Geographic variation and non-additive effects of pyrazines in the chemical defence of an aposematic moth
BirdGeoFinControl.txt and Pyrazines_Populations.txt are the raw data in a format that can be opened in Wordpad or Excel.
The BirdGeoFinControl.txt file includes raw data for the predators' response to the thoracic fluid of Georgian and Finnish Wood Tiger Moth populations, while the Pyrazines_Populations.txt is the measure of pyrazines of different Wood Tiger Moth populations
The headers of columns for the BirdGeoFinControl.txt are defined below:
ID: ID of individual moth
Volume: volume of the Wood Tiger Moth thoracic fluid (microL)
population: population of each individual
location: location (country) from where each individual is from
origin: laboratory origin or wild origin of each individual
BirdID: ID individual of each bird
Date: date of the experiment
Trial: trial (1,2,3,4). trial 1 and 4 were water and 2 and 3 were with the thoracic fluid
Hesitation: hesitation time measured as time in seconds from seeing the oat to pecking/eating the first oat
Length: duration time of each trial (min)
Proportion_eaten: Proportion of oat eaten in each trial
Beak_cleaning: a disgust behaviour measured as the number of bouts where the bird wiped its beak against a surface such as the perch
Drinking: the number of times the bird drank water, which is a behaviour that can increase in response to distasteful food
The headers of columns for Pyrazines_Populations.txt are defined below:
sample: ID of individuals
population: population of each individual
location: location (country) from where each individual is from
origin: laboratory origin or wild origin of each individual
year: year of the sampling
SBMP: SBMP measurament from the GC-MS
IBMP: IBMP measurament from the GC-MS
1ng_SBMP: standard amount of SBMP
1ng_IBMP: standard amount of IBMP
SBMP_ng: SBMP amount in NG
IBMP_ng: IBMP amount in ng
ratio: ratio of IBMP to SBMP
The headers of columns for weight_LABmoths.txt are defined below:
sample: ID of individuals
population: population of each individual
location: location (country) from where each individual is from
origin: laboratory origin or wild origin of each individual
year: year of the sampling
SBMP: SBMP measurament from the GC-MS
IBMP: IBMP measurament from the GC-MS
1ng_SBMP: standard amount of SBMP
1ng_IBMP: standard amount of IBMP
SBMP_ng: SBMP amount in NG
IBMP_ng: IBMP amount in ng
ratio: ratio of IBMP to SBMP
weight: weight in milligrams of the wood tiger moths lab populations
Methods
Methods are described in the related paper.