Chemoecology

, Volume 18, Issue 1, pp 39–51 | Cite as

No simple sum: seasonal variation in tannin phenotypes and leaf-miners in hybrid oaks

  • Christopher T. Yarnes
  • William J. Boecklen
  • Juha-Pekka Salminen
Article

Abstract.

Parent-hybrid asymmetries in the biosynthesis of defense chemistry are believed to affect the distribution of herbivorous insects within plant hybrid zones. While tannins are often produced as complex, dynamic mixtures, the ecological effects of biological and ontogenetic variation in tannin metabolism within hybrid zones are poorly understood. Here, we examine correlations between the seasonal variation of absolute and relative concentrations of individual ellagitannins and total proanthocyanidins in the Quercus gambelii × Q. grisea hybrid complex and a community of leaf-mining Lepidoptera (Gracillariidae, Heliozelidae, Nepticulidae, Tischeriidae), and examine the interactive effects between tannins on leaf-miner abundance. We found strong seasonal variation in oak tannin phenotypes, but two general phenotypes are characteristic of oaks of the Q. gambelii × Q. grisea complex, based upon biosynthetic variation in high molecular weight ellagitannins. Leaf-miner community structure was significantly correlated with the dominant tannin phenotypes in the Q. gambelii × Q. grisea hybrid zone in mid-summer (July, August). Additionally, leaf-miner density was significantly negatively correlated with the ratio of vescalagin-derivatives and total proanthocyanidins in August and September. Overall, hybridization affects biological and ontogenetic variation in ellagitannin and proanthocyanidin biosynthesis within the Q. gambelii × Q. grisea hybrid complex and this variation correlates with herbivore distribution and abundance. Future studies of phenolic chemistry in plant-herbivore interactions in hybrid zones should include a more rigorous quantification of tannin phenotypes as complex, temporally dynamic mixtures.

Keywords.

Hybridization Quercus ellagitannin leafminer phenotype defense 

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Copyright information

© Birkhaeuser 2007

Authors and Affiliations

  • Christopher T. Yarnes
    • 1
    • 2
    • 4
  • William J. Boecklen
    • 1
    • 2
  • Juha-Pekka Salminen
    • 3
  1. 1.Laboratory for Ecological ChemistryInstitute for Natural Resource Analysis and ManagementLas CrucesUSA
  2. 2.Department of BiologyNew Mexico State UniversityLas CrucesUSA
  3. 3.Laboratory of Organic Chemistry and Chemical Biology, Department of ChemistryUniversity of TurkuTurkuFinland
  4. 4.Biology DepartmentEmory & Henry CollegeEmoryUSA

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