Cuticular Hydrocarbon Trails Released by Host Larvae Lose their Kairomonal Activity for Parasitoids by Solidification

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Sarah Awater-Salendo - , Julius Kühn Institute - Federal Research Centre for Cultivated Plants (Author)
  • Dagmar Voigt - , Institute of Botany (Author)
  • Monika Hilker - , Institute for Systems Biology (Author)
  • Benjamin Fürstenau - , Julius Kühn Institute - Federal Research Centre for Cultivated Plants (Author)

Abstract

Successful host search by parasitic wasps is often mediated by host-associated chemical cues. The ectoparasitoid Holepyris sylvanidis is known to follow chemical trails released by host larvae of the confused flour beetle, Tribolium confusum, for short-range host location. Although the hexane-extractable trails consist of stable, long-chain cuticular hydrocarbons (CHCs) with low volatility, the kairomonal activity of a trail is lost two days after release. Here, we studied whether this loss of kairomonal activity is due to changes in the chemical trail composition induced by microbial activity. We chemically analyzed trails consisting of hexane extracts of T. confusum larvae after different time intervals past deposition under sterile and non-sterile conditions. GC-MS analyses revealed that the qualitative and quantitative pattern of the long-chain CHCs of larval trails did not significantly change over time, neither under non-sterile nor sterile conditions. Hence, our results show that the loss of kairomonal activity of host trails is not due to microbially induced changes of the CHC pattern of a trail. Interestingly, the kairomonal activity of trails consisting of host larval CHC extracts was recoverable after two days by applying hexane to them. After hexane evaporation, the parasitoids followed the reactivated host trails as they followed freshly laid ones. Cryo-scanning electron microscopy showed that the trails gradually formed filament-shaped microstructures within two days. This self-assemblage of CHCs was reversible by hexane application. Our study suggests that the long-chain CHCs of a host trail slowly undergo solidification by a self-assembling process, which reduces the accessibility of CHCs to the parasitoid's receptors as such that the trail is no longer eliciting trail-following behavior.

Details

Original languageEnglish
Pages (from-to)998-1013
Number of pages16
JournalJournal of chemical ecology
Volume47
Issue number12
Publication statusPublished - Dec 2021
Peer-reviewedYes

External IDs

PubMedCentral PMC8642257
Scopus 85114903864
ORCID /0000-0003-2772-8504/work/142250992

Keywords

Keywords

  • Animals, Gas Chromatography-Mass Spectrometry, Host-Parasite Interactions, Hydrocarbons/chemistry, Larva/chemistry, Odorants/analysis, Olfactory Perception, Pheromones/chemistry, Tribolium/chemistry, Wasps/physiology

Library keywords