A new class of inhibitors were discovered based on discovery of enzymes present in salivary sheaths. Two of the six tested inhibitors blocked sheath formation. An additional six different proteins belonging to the same functional class of proteins were identified based on their potential to bind to salivary sheath subunits. These proteins were tested for sheath inhibition, but none caused inhibition of sheath biosynthesis or alterations in sheath appearance. The ultimate goal of this screening approach is to identify a diverse set of sheath inhibitors that can be used in combination to function as effective topically applied blockers of psyllid feeding on citrus. If feeding is inhibited at the initiation of feeding and prevents the psyllid from successfully reaching the phloem, this method of psyllid control will prevent the psyllid form acquiring or transmitting the bacterium that causes citrus greening.