Which processes shape grapevine moth immune response against parasitism? Plastic or selective response Fanny Vogelweith, Denis Thiéry, Yannick Moret & Jérôme Moreau 15th International Symposium on Insect-Plant Relationships

Tritrophic interactions Trophic levels Secondary consummers Natural ennemies Primary produceurs Plants Primary consummers Phytophagous Interdependences Community regulation ≠ rate of parasitism Moreau et al – Biological control  Hypotheses?

Intimacy of the relationships between pests and natural enemies Plant composition Immune system Natural ennemiesPhytophagous insect Host plant Bukovinsky et al Resistance

Haemocyte Insect larval Haemolymph Quinones + Cytotoxic compounds Melanin Egg of parasitoid PAMP PRP P PO Antimicrobial peptides Constitutive and induced defenses Insect immune system Tyrosine

Genetic Variation of insect immune system Environment Cotter et al Nutrition (Siva-Jothy & Thompson 2002 Schmid-Hempel 2003) Density (Barnes & Siva- Jothy 2000)

What we already know… Grape variety effect on : Vogelweith et al Functional Ecology Moreau et al Biological Control Relationship between immunity and parasitism Immune parameters Parasitism Vogelweith et al Naturwissenschaften

ρ = 0.71 p < CB TK CC DGF VI OE MER DB PR CBS CBG Parasitism Larval immune system Naïves larvae Relationship between parasitism and immunity

Plastic response Larval immune system Parasitism How to explain this relationship

Plastic response Rearing larvae at L4 Immune measures P PO 6 days Presence or Absence Parasitoïd 2 parasitoïd species tested C. capitator & P. nigrina

Absence of parasitoïd Plastic response Campoplex capitator Phytomyptera nigrina P PO a a a a a a a aa

Plastic response Are the larvae able to detect parasitoids? a a a a a a b b a a b b Dead larvaeAlive larvaeChrysalis Individual proportion +/- C. I. 95% AbsC.c.P.n. L.c. AbsC.c.P.n. L.c. AbsC.c.P.n. L.c. Vogelweith et al Plos One

Synthetic value of immune system Parasitism Conclusion Larvae detect parasitoïds But no effect on immune parameters Plastic response Selective response Plastic response Vogelweith et al – Plos One

Selective response Average parasitism : recording of 9 populations between 2008 and 2012 Immune parameters measures on naïve larvae in 2012

Mean rate of parasitism PO (x10 3 miliunité/min) Total-PO ( x10 3 miliunité/min) Mean rate of parasitism ρ = 0.62 ; p = 0.07; I.C. 95% = [-0.10; 0.90] ρ = 0.65; p = 0.05 ; I.C. 95% = [-0.03; 0.98] Selective response ρ = 0.72; P = 0.03; I.C. 95% = [0.03; 0.94] PO P

Conclusion 1 st year 2 nd year 3 rd year

Synthetic value of immune system Parasitism Conclusion Positive relationship between parasitism & larval immunity Plastic response Selective response

Acknowledgments A. Balourdet Ingenieer D. Thiéry Researcher Y. Moret Researcher J.P. Troussard Ingenieer M.-L. Felix Trainee J. Moreau Lecturer E. Desvignes Trainee S. Motreuil Ingenieer

Thank you for your attention

Conclusion Parasitoïds Grape varieties Larvae - Immunity - In lab and in vineyards Immunity modulation by ≠ selective pressure

PO-PPO activities Haemocyte concentration Immune measures Induced defense Antimicrobial activiy Constitutive defenses

Haemocyte concentration Grape varieties Haemocyte concentration (x10 3 haemocytes/µL)

Antimicrobial activity gwpgpn pgpnrg se cfcsmpgy y mrpny mrpn army cigr gy Grape varieties Percentage of individual with an antimicrobial activity CBTKCCDGFVIMEROEDBPRCBGCBS a ab b a b ac b abc ALSACEAQUITAINEBOCHAMPAGNEPACA RHONE ALPES

Parasitism Grape varieties

Relationship between parasitism and immunity Haemocytes PO-PPO activities Antimicrobial activity P PO P P P P Synthetic value of immune system

Parasitism Synthetic value of immune system Relationship between parasitism and immunity

Involvement of immune system in tritrophic interactions 1 st year 2 nd year

Sampling in natural populations May 2011 Vogelweith et al Naturwissenschaften