Use of VOC Chambers to evaluate the impact of microbial volatile compounds on dry grain insect pests

Samuel Álvarez-García; Santiago Gutiérrez; Pedro A Casquero

doi:10.1016/j.mex.2022.101734

Use of VOC Chambers to evaluate the impact of microbial volatile compounds on dry grain insect pests

MethodsX. 2022 May 18:9:101734. doi: 10.1016/j.mex.2022.101734. eCollection 2022.

Authors

Samuel Álvarez-García¹, Santiago Gutiérrez², Pedro A Casquero¹

Affiliations

¹ Grupo Universitario de Investigación en Ingeniería y Agricultura Sostenible (GUIIAS), Instituto de Medio Ambiente, Recursos Naturales y Biodiversidad, Universidad de León, Avenida Portugal 41, 24071 León, Spain.
² Grupo Universitario de Investigación en Ingeniería y Agricultura Sostenible (GUIIAS), Área de Microbiología, Escuela de Ingeniería Agraria y Forestal, Universidad de León, Campus de Ponferrada, Avenida Astorga s/n, 24401 Ponferrada, Spain.

Abstract

Although increasing focus is being given to the control of insect pests with natural products, the study of volatile mediated microbe-insect interactions has been largely neglected so far. Currently, no standardized method is available for the in vitro evaluation of the effects produced on insects by Volatile Organic Compounds (VOCs) directly emitted by actively growing microbial strains. This manuscript presents a reliable protocol using VOC Chambers (Álvarez-García et al., 2021) to assess these effects and specifically those exerted on dry grain insect pests. The methodology also serves to evaluate the impact of these volatile interactions on the grain damage produced by the insects. It allows to vary the level of gas exchange with the environment, thus providing different experimental conditions to emulate diverse natural ones in which these interactions may occur. Our method adapts the use of VOC Chambers for the evaluation of microbe-insect volatile interactions and the in vitro screening of microbial strains that produce potentially bioactive VOCs against insects. It allows assessing the effects of these volatile interactions on the damage produced by insect pests on stored dry grains. Sealed and unsealed setups can be used to determine the impact of ventilation and gas exchange on these interactions.

Keywords: Acanthoscelides obtectus; Dry grain; Fungal volatile; Microbe-insect interaction; Pest; Phaseolus vulgaris; Storage; Trichoderma harzianum; Trichodiene; VOC.