Appendix C. Two tables with descriptive information about the larval parasitoids reared from autumnal moths.

Two tables with descriptive information about the larval parasitoids reared from autumnal moths

Appendix A. Four color photographs of the study site showing experimental cages and supporting results of the parasitoid-exclusion experiment.

Four color photographs of the study site showing experimental cages and supporting results of the parasitoid-exclusion experiment

Appendix B. Graphs providing abundance data for each replication unit of the parasitoid-exclusion experiment.

Graphs providing abundance data for each replication unit of the parasitoid-exclusion experiment

Photos of the real and the artificial larvae.

<p>A) A fifth instar <i>Epirrita autumnata</i> larva on a branch. B) Larval feeding damage on mountain birch (<i>Betula pubescens</i> ssp. <i>czerepanovii</i>) leaves. C) A plasticine larva on a mountain birch branch. D). A beak marking on a plasticine larva indicating a predation attempt by an insectivorous bird.</p

Spearman's rank correlation coefficients (<i>r</i>_S) between individual volatile organic compound emissions in the first measurement (6 days after the start of defoliation) and the total sum of damaged plasticine larvae per tree (<i>n</i> = 28 trees) in both herbivore and control trees.

<p>Column ‘No.’ refers to the number of the compound in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0002832#pone-0002832-g002" target="_blank">Figure 2</a>. Column ‘Group’ indicates into which group of VOCs the compound belongs. (^*: <i>p</i><0.05; ^**: <i>p</i><0.01).</p

Scatter plots of three volatile organic compounds (VOCs) and the total sum of damaged plasticine larvae in herbivore (black dots) and control (grey dots) trees (<i>n</i> = 28). A) (<i>E</i>)-DMNT, B) linalool and C) β-ocimene.

<p>Note the different x-axes in the panels.</p

The daily numbers of damaged plasticine larvae found from herbivore (black bars) and control (grey bars) birches.

<p>The X-axis shows the number of days since the start of defoliation by autumnal moth larvae in the herbivore trees. Solid and hatched arrows show the days when the volatile organic compounds (VOCs) and net photosynthesis rate, respectively, were measured.</p

The volatile organic compound (VOC) emissions from herbivore (black bars) and control (grey bars) birch branches (ls means+SE from statistical models are shown).

<p>A) six days, <i>n</i> = 14 in both control and herbivore trees, and B) 10–11 days since the start of defoliation by autumnal moth larvae, control: <i>n</i> = 7 and herbivore: <i>n</i> = 6. Compounds: (1) α-pinene, (2) β-myrcene, (3) limonene, (4) β-ocimene, (5) linalool, (6) (<i>E</i>)-DMNT, (7) α-copaene, (8) α-humulene, (9) caryophyllene oxide, (10) (<i>E</i>)-β-caryophyllene, (11) β-bourbonene, (12) cis-3-hexenyl acetate, (13) cis-3-hexen-1-ol+(<i>E</i>)-2-hexenal, (14) nonanal, (15) cis-3-hexenyl butyrate. (*: <i>p</i><0.05; **: <i>p</i><0.01; ***: <i>p</i><0.001).</p

Additional file 1: of Species and abundance of ectoparasitic flies (Diptera) in pied flycatcher nests in Fennoscandia

Molecular analysis of puparia and adult bird louse flies. Species and abundance of louse flies (Ornithomya spp.) and blowflies (Protocalliphora spp.) in nests of the pied flycatcher. (DOCX 46 kb

Herbivory by an Outbreaking Moth Increases Emissions of Biogenic Volatiles and Leads to Enhanced Secondary Organic Aerosol Formation Capacity

In addition to climate warming, greater herbivore pressure is anticipated to enhance the emissions of climate-relevant biogenic volatile organic compounds (VOCs) from boreal and subarctic forests and promote the formation of secondary aerosols (SOA) in the atmosphere. We evaluated the effects of <i>Epirrita autumnata</i>, an outbreaking geometrid moth, feeding and larval density on herbivore-induced VOC emissions from mountain birch in laboratory experiments and assessed the impact of these emissions on SOA formation via ozonolysis in chamber experiments. The results show that herbivore-induced VOC emissions were strongly dependent on larval density. Compared to controls without larval feeding, clear new particle formation by nucleation in the reaction chamber was observed, and the SOA mass loadings in the insect-infested samples were significantly higher (up to 150-fold). To our knowledge, this study provides the first controlled documentation of SOA formation from direct VOC emission of deciduous trees damaged by known defoliating herbivores and suggests that chewing damage on mountain birch foliage could significantly increase reactive VOC emissions that can importantly contribute to SOA formation in subarctic forests. Additional feeding experiments on related silver birch confirmed the SOA results. Thus, herbivory-driven volatiles are likely to play a major role in future biosphere-vegetation feedbacks such as sun-screening under daily 24 h sunshine in the subarctic