Journal of Chemical Ecology

, Volume 28, Issue 2, pp 317–331

Antimicrobial Activity of Exocrine Glandular Secretion of Chrysomela Larvae

Article

DOI: 10.1023/A:1017934124650

Cite this article as:
Gross, J., Podsiadlowski, L. & Hilker, M. J Chem Ecol (2002) 28: 317. doi:10.1023/A:1017934124650

Abstract

The exocrine glandular secretions of leaf beetle larvae of the taxon Chrysomela are well-known defensive devices used against some generalist predators. Salicylaldehyde is the major repellent component of secretions emitted by larvae of Chrysomela vigintipunctata and C. lapponica, which feed on salicin-rich Salicaceae. In this study, we examined whether salicylaldehyde is also active against the entomopathogenic fungus Metarhizium anisopliae. The germination and growth of this fungus was strongly inhibited when salicylaldehyde was applied directly onto the blastospores. The salicylaldehyde concentration of the larval secretions of the tested willow feeding Chrysomela larvae was much higher than the one necessary to display this antifungal activity. Additionally, salicylaldehyde was shown to reduce germination and growth of M. anisopliae via the gas phase over a distance of 45 mm. Further studies on the antimicrobial activity of the salicylaldehyde-containing secretions of Chrysomela larvae revealed that they act nonspecifically against prokaryotic (Escherichia coli) and eukaryotic cells (Saccharomyces cerevisiae and Trichoplusia ni). All antimicrobial and cytotoxic effects detected proved to be due to salicylaldehyde. The larval secretions of the birch-feeding allospecies of C. lapponica, that do not contain salicylaldehyde, but mainly carboxylic acids and their esters, showed no detectable effects on bacteria or fungi and no cytotoxic effects against insect cells. The results are discussed with respect to their ecological relevance.

Chrysomela vigintipunctata Chrysomela lapponica larval secretion antimicrobial activity cytotoxicity entomopathogens Metarhizium anisopliae salicylaldehyde carboxylic acids carboxylic esters 

Copyright information

© Plenum Publishing Corporation 2002

Authors and Affiliations

  • Jürgen Gross
    • 1
  • Lars Podsiadlowski
    • 1
  • Monika Hilker
    • 1
  1. 1.Institut für BiologieFreie Universität BerlinBerlinGermany

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