EPN Chemical ecology and new techniques for below ground sampling and analyses of volatile semiochemicals

Authors: Alborn, Hans

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/4/2016
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: It is well established that herbivory induced plant volatiles (HIPVs) attract natural enemies of the herbivores. Utilizing this plant response has become a fundamental part of above ground IPM programs. We now know that also roots can release HIPVs and that these compounds attract beneficial organisms such as entomopathogenic nematodes. However, to add to the rhizospere complexity, volatile organic compounds (VOCs) can also be produced by insects, microorganisms and possibly nematodes. In soil, these VOCs are diffusing into airspace where they might interact with water as well as soil particles, affecting their dispersal. To bypass this complexity, root-related VOCs have typically been sampled with techniques producing chromatographic profiles with little relevance for the system intended to be studied. We report progress on designing probes for direct in vivo (green house or field) in-soil sampling of VOCs, a technique that when combined with low degradation on column thermal desorption GC/MS analyses allow for high sensitivity and minimally intrusive sampling. These new techniques make it possible to continuously monitor changes in the composition of root zone VOC in response to insect or nematode infestations. We also report recent discoveries of the dynamics of EPNs ability to utilize these host related VOCs that in combination with aggregation and trail pheromones makes mass infection of host insects possible. Finally we will discuss how these new techniques and discoveries can be utilized to improve the use of EPNs in IPM programs.