Submitted to: Oecologia
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/31/2001
Publication Date: 3/24/2001
Citation: Sword, G.A. 2001. Tasty on the outside, but toxic in the middle. grasshopper regurgitation and host plant-mediated toxicity to a vertebrate predator. Oecologia. 128:416-421. Interpretive Summary:
Technical Abstract: Regurgitation by arthropods is often considered to be a redimentary form of defense against predators. In phytohagous insects, regurgitate composi- tion will vary with diet, and plant secondary compounds from host plants can contribute to the effectiveness of regurgitate deterrence. Regurgita- tion in response to predator attack is particularly common in grasshoppers. .However, there is little empirical evidence in favor of grasshopper re- gurgitation as an effective antipredator mechanism in natural predator- prey systems. In particular, studies of the effect of grasshopper diet on regurgitate deterrence to vertebrate preditors are lacking.This study investigated the relationship between diet and predator defense in the grasshopper. Schistocerca emarginata (=lineta) (Orthoptera: Acridadie). Using the insectivorous lizard, Anolis carolinensis (Iguanidae), as a predator, I demonstrate that consumption of Ptelea trifoliata (Rutaceae) by S. emarginata can confer distastefulness as well as toxicity. Regurgit- ation deterrence is mediated structly by host plant material in the gt and does not require an enteric contribution from the grasshopper. Regurgitat- tion by Ptelia - fed S. emarginata can result in rejection prior to inges- tion by A. carolinensis and can enable grasshoppers to survive predator attacks.