Patent ID: 8004292

Claim:
A system for monitoring the feeding behavior of insects, the system comprising: an insect electrode, the insect electrode being attached to an insect feeding on a host plant; a head stage amplifier system, the head stage amplifier system being connected to the insect electrode, the head stage amplifier system comprising: (a) an operational amplifier assembly; and (b) a switched resistor assembly connected to the operational amplifier assembly, the switched resistor assembly comprising multiple selectable resistors yielding multiple selectable levels of input resistance for the head stage amplifier; (c) a resistance selection means enabling an operator to select one of the selectable resistors and thereby specify an input resistance for the head stage amplifier; wherein the operator connects the insect to the insect electrode and initiates an evaluation of the insect, the operator using the resistance selection means to select the input resistance of the head stage amplifier based on the insect.