Puke, blood, allelopathic chemicals: chemical ecology of the Florida rosemary grasshopper

Schistocerca ceratiola, the Florida rosemary grasshopper endemic to central Florida, is monophagous on Ceratiola ericoides, scrub rosemary. Scrub rosemary is highly allelopathic because of the secondary compound it produces, ceratiolin. Ceratiolin decomposes into hydrocinnamic acid which has been shown to greatly inhibit seed germination and growth in many other scrub plants. I have used chromatographic methods to determine the fate of ceratiolin once ingested by the grasshopper. I collected specimens from rosemary balds throughout Florida and extracted regurgitate and hemolymph for investigation. I compared the chromatographs of the regurgitate and hemolymph to a chromatograph of a standard I prepared by isolating ceratiolin from the plant. Thin layer chromatography reveals the presence of ceratiolin in the regurgitate but not in the hemolymph. High performance liquid chromatography provides similar results, suggesting that ceratiolin is confined to the digestive system of the grasshopper.