Most sap-feeding insects tap the phloem, which carries sugar. Sharpshooters tap the xylem instead, where the fluid is dilute and under negative pressure, so the insect must both suck against tension and process a very large throughput. Measured intake rates for xylem feeders reach well over a hundred times body mass per day, among the highest of any animal relative to size, driven by a powerful cibarial pump in the head.
The excess leaves as droplets flicked away by the abdomen, which is the origin of both the name sharpshooter and the misleading garden term rain tree, applied to plants beneath a heavy infestation.
The agricultural significance is indirect. Xylella fastidiosa colonises the insect's foreparts and is transmitted plant to plant as it feeds, causing Pierce's disease in grapes and related diseases in almond, citrus and olive. The introduction of this large, strong-flying sharpshooter to California in the 1990s substantially widened the reach of a bacterium already present.