Technical Abstract: Corn leafhopper, Dalbulus maidis, is a vector of three corn pathogens that have become limiting factors for corn production in some areas of the Americas. Insect feeding plays an important role in acquisition and inoculation of pathogens by their insect vectors, and thus spread of the pathogen. The specific objective of this work is to understand the different stylet penetration activities performed by this insect while it feeds on corn plants, with the long-term goal of identifying sources of resistance to the insect vector in corn. Using electrical penetration graph (EPG) technology, six distinct waveforms were characterized and correlated with different stylet activities of D. maidis by monitoring transmission of spiroplasmas and excretion of honeydew. Major waveforms defined correspond to stylet pathway (waveform 1), active ingestion from non-sieve elements (waveform 2), nonvascular probing (waveform 3), phloem contact (waveform 4), phloem sieve element ingestion (waveform 5), and oviposition (waveform 6). Results support previous findings with this species, and also indicate that some waveforms (2, 4 and 5) are caused by biopotentials generated during probing, as was previously found for other hemipteran species. This work provides basic information relevant to the understanding of stylet penetration behavior of D. maidis and to the characterization of potential sources of insect-resistant corn.