ESR Update - First, I focused at the molecular level, analyzing proteins and metabolites present in the saliva. But I also wanted to investigate the mechanical aspects to see whether behavior is playing an important role in the damage. After conducting behavioral experiments we determined that N. tenuis spends longer time feeding on the plant and pierces the plant tissue more times than Macrolophus pygmaeus—another zoophytophagous predatory bug used in biocontrol that doesn’t cause plant damage. However, I got intrigued about what they do when they insert the stylet in the plant… is there any difference in the salivation? Does N. tenuis ingest more contents from the plant than M. pygmaeus? Do they feed on the same tissues? And the best approach to answer these questions is the Electrical Penetration Technique (EPG), so last September I decided to go on my first secondment to Wageningen University and Research Centre (WUR) to be trained in this technique in the Laboratory of Entomology. EPG consists in making an electrical circuit with the plant and the insect, so that when the insect pierces the plant the circuit is closed and changes in the voltage give information about the feeding activity (e.g. salivation, ingestion, cell-rupture) and the tissue the stylet is reaching inside the plant. However, this technique gets tricky depending on the feeding mechanism of the insect. For instance, aphids secrete a salivary sheath while feeding, hence the position of the stylet inside the plant tissue becomes easier to locate using staining methods. On the other hand, species like N. tenuis and M. pygmaeus do not produce a salivary sheath, thus staining techniques don’t work and it’s more difficult to identify the tissues reached by the stylet. Additionally, to the best of our knowledge, there are not previous EPG studies on N. tenuis or M. pygmaeus so the identification and characterization of the electric profiles represents and exciting challenge! I spent six weeks immobilizing and wiring nymphs and adults of both species, and recording their behaviors with a Giga-8d Basic EPG System. I am now back at IVIA in Spain with the results and I expect to have lots of interesting information about the feeding behavior of these zoophytophagous in the next few months!