Ricardo Machado

Research interests

Molecular and Chemical Ecology of Belowground Ecosystems

My current research focuses to understand the chemical and molecular ecology of belowground ecosystems. More specifically, I want to discover the plant metabolites that determine the behaviour and performance of root herbivores, and whether or not the feeding preferences of root herbivores impact their resistance to natural enemies. There is abundant literature regarding the metabolites that are potentially used by root herbivores to locate their host plant. They for instance use CO₂, volatile organic compounds, water soluble metabolites and finally endogenous metabolites. What is much less understood is the genes that regulate host location and feeding preferences. In this context, we identify and characterize odour and taste receptors. We identify them by homology and modelling, and characterize them by silencing them in the insect by RNAi followed by behavioural and host location experiments. For this, we use belowground olfactometers, small arenas, couple metabolomic data with within-plant foraging behavioural experiments, and conduct also host location experiments using more complex arenas. In addition, I am currently investigating the consequences of feeding behaviour for other trophic levels. I want to understand how certain plant nutrients for instance determine foraging behaviour, and whether insect feeding preferences impact resistance against entomopathogenic nematodes and predators.