DOI: 10.5061/dryad.gxd2547hh
title: Phenotypic plasticity in chemical defence allows butterflies to diversify host use strategies

description: Hostplant specialization is a major force driving ecological niche
 partitioning and diversification in insect herbivores. The cyanogenic
 defences of Passiflora plants keeps most herbivores at bay, but not larvae
 of Heliconius butterflies, which can both sequester and biosynthesize
 cyanogenic compounds. Here, we demonstrate that both Heliconius cydno
 chioneus, a host plant generalist, and H. melpomene rosina, a specialist,
 have remarkable plasticity in their chemical defence. When feeding on
 Passiflora species with cyanogenic compounds they can readily sequester,
 both species downregulate the biosynthesis of these compounds. In
 contrast, when fed on Passiflora plants that do not contain cyanogenic
 glucosides that can be sequestered, both species increase biosynthesis.
 This biochemical plasticity comes at a significant fitness cost for
 specialist like H. m. rosina, as growth rates for this species negatively
 correlate with biosynthesis levels, but not for a generalist like H. c.
 chioneus. In exchange, H. m rosina has increased performance when
 sequestration is possible as on its specialised hostplant. In summary,
 phenotypic plasticity in biochemical responses to different host plants
 offers these butterflies the ability to widen their range of potential
 host within the Passiflora genus, while maintaining their chemical
 defences.
description: This dataset correspond to body measurements (forewing length,
 body length, adult weight, and pupal weight) and cyanogen concentrations
 of H. cydno chioneus and H. melpomene rosina raised on P. biflora, P.
 menispermifolia, P. vitifolia and P. platyloba. The common garden
 experiment was conducted at the Smithsonian Tropical Research
 Institute (Panama).
description: LC-MS analyses were carried out as described in Pinheiro de
 Castro, É. C., Zagrobelny, M., Zurano, J. P., Zikan Cardoso, M.,
 Feyereisen, R., & Bak, S. (2019). Sequestration and biosynthesis
 of cyanogenic glucosides in passion vine butterflies and consequences for
 the diversification of their host plants. <i>Ecology and
 evolution</i>, <i>9</i>(9), 5079-5093.
 Each whole butterfly was  homogeinized in 1.5 mL methanol
 80%. All samples were centrifuged at 10,000 x g for 5 min and
 the supernatant filtered (Anapore 0.45 µm, Whatman) to remove insoluble
 components. Samples were diluted 50X and injected (3 uL) in
 a Agilent 1100 Series LC (Agilent Technologies, Germany)
 hyphenated to a Bruker HCT-Ultra ion trap mass spectrometer (Bruker
 Daltonics, Bremen, Germany). Deidaclin/Tetraphyllin A
 (RT 5.5 min, [M+Na]<sup>+ </sup>at <i>m/z</i>
 294), linamarin (RT 2.4 min, [M+Na]<sup>+ </sup>at
 <i>m/z</i> 310), lotaustralin (RT 5.5 min, [M+Na]<sup>+
 </sup>at <i>m/z</i> 284), prunasin (RT 7.0 min,
 [M+Na]<sup>+ </sup>at <i>m/z</i> 317) and
 amygdalin (RT 6.6 min, [M+Na]<sup>+ </sup>at
 <i>m/z</i> 480)  were detected and their RTs compared to
 authentic standards (Engler et al. 2000; Jaroszewski et al. 2002; Møller
 et al. 2016).  Tetraphyllin B-sulfate (RT 1.3 min, [M+Na]<sup>+
 </sup>at <i>m/z</i> 390) and passibiflorin (RT 5.8 min,
 [M+Na]<sup>+ </sup>at <i>m/z</i> 456) were
 identified in the plant samples by their m/z, fragmentation pattern
 (MS/MS) and comparison with data reported in the literature regarding
 these compounds. Please utilize the software 
 Compass Dataanalysis from Bruker to open the raw chemical data
 (samples, washed and standards). In the excel file "Cyanogen
 Datasheet.xlsx", you will find information about the species/diet
 treatment corresponded to each sample (1-105) as well as the  cyanogenic
 glucoside concentrations in the standard curve (ST1-ST7).  README.txt
 contains a description of all the information in the file "Cyanogen
 Datasheet.xlsx".  A file with all the data Analysed in this srudy is
 also available as .csv (("alldata.csv").