When an insect pierces the surface of a plant to feed, much of the action takes place in the plant's interior. A device called the Electrical Penetration Graph (EPG) is a critical tool for peering into the process.

Now a new type of EPG developed by U. S. Department of Agriculture (USDA) entomologists is giving scientists the clearest view yet of the wars waged between piercing-sucking insects and the plants they attack.

The EPG was developed by Elaine Backus at the Agricultural Research Service (ARS) San Joaquin Valley Agricultural Sciences Center, in Parlier, California,...