DOI: 10.5061/dryad.zpc866tfz
title: Diet influences resource allocation in chemical defence in an aposematic moth

description: For animals that synthesise their chemical compounds de novo, resources,
 particularly proteins, can influence investment in chemical defences and
 nitrogen-based wing colouration such as melanin. Competing for the same
 resources often leads to trade-offs in resource allocation. We manipulated
 protein availability in the larval diet of the wood tiger moth, Arctia
 plantaginis, to test how early life resource availability influences
 relevant life history traits, melanin production, and chemical defences.
 We expected higher dietary protein to result in more effective chemical
 defences in adult moths and a higher amount of melanin in the wings.
 According to the resource allocation hypothesis, we also expected
 individuals with less melanin to have more resources to allocate to
 chemical defences. We found that protein-deprived moths had a slower
 larval development, and their chemical defences were less unpalatable for
 bird predators, but the expression of melanin in their wings did not
 differ from that of moths raised on a high-protein diet. The amount of
 melanin in the wings, however, unexpectedly correlated positively with
 chemical defences. Our findings demonstrate that the resources available
 in early life have an important role in the efficacy of chemical defences,
 but melanin-based warning colours are less sensitive to resource
 variability than other fitness-related traits.
description: # Diet influences resource allocation in chemical defence but not melanin
 synthesis in an aposematic moth Melanin_BirdResponse.txt and
 LifeHistoryMales.txt are the raw data in a format that can be opened in
 Wordpad or Excel. The Melanin_BirdResponse.txt file includes raw data for
 the predators' response to the thoracic fluid of Estonian male wood
 tiger moths and the measurement of the melanin amount in the same moths,
 while the LifeHistoryMales.txt is the measure of life-history traits of
 those Estonian male wood tiger moths The headers of columns for the
 Melanin_BirdResponse.txt are defined below: * birdID: ID individual of
 each bird * sex: sex of the bird * age: indicate whether the bird was
 Juvenile/Adult * treatment: diet treatment of the individual moth *
 idmoth: ID of individual moth * family: the family of the moth *
 colour:indicates the melanisation of the moth's hindwing classified
 by eyes * Trial: trial (1,2,3,4). trial 1 and 4 were water and 2 and 3
 were with the thoracic fluid * tsee: time (in seconds) recorded when the
 bird see the bait (oat flake) with the thoracic fluid * tapp: time (in
 seconds) recorded when the bird approach the bait (oat flake) with the
 thoracic fluid * tattack: time (in seconds) recorded when the bird grab
 the bait (oat flake) with the thoracic fluid * teat: time (in seconds)
 recorded when the bird starts to eat the bait (oat flake) with the
 thoracic fluid * handltime: time (in seconds) recorded when the bird
 handle the bait (oat flake) with the thoracic fluid * lateat: hesitation
 time (in seconds) measured as time in seconds from seeing the oat to
 pecking/eating the first oat * propeat:Proportion of bait (oat flake)
 eaten in each trial * pbw: beak cleaning a disgust behaviour measured as
 the number of bouts where the bird wiped its beak against a surface such
 as the perch (indicates as 0, if it didn't happen or 1 if it happen)
 * nbw: number of times the bird beak wipes * pw: drinking, indicates when
 bird drank water, which is a behaviour that can increase in response to
 distasteful food (indicates as 0, if it didn't happen or 1 if it
 happen) * nw: number of time the bird drinks water * tfinal:final time
 when the trial end (in seconds) * tduration: duration time (in seconds) of
 the entire trial * BlackCover: Melanin amount measured (as number of
 pixels) 'na' values: indicates values not available The headers
 of columns for LifeHistoryMales.txt are defined below: * MIR17: label
 indicated the year (2017) * ID: ID of individual moth * Family: family of
 the moth * Individual_number: individual number of the moth * treatment:
 diet treatment of the individual moth * larva_date: date of the egg
 eclosion * pupa_date: date of when the individual from larvae it becames
 pupae * pupa_weight: weight of the pupae (mg) * adult_date: date of the
 pupa eclosion to adult * survival: whether the individual survived or not
 * development_time_days: time in days to develop * sex: sex of the moth *
 BlackCover: Melanin amount measured (as number of pixels) * N_volume:
 Volume of the thoracic fluid (chemical defences) (μl) 'na'
 values: indicates values not available