Developmental inhibition ofSpodoptera litura (Fab.) larvae by a novel caffeoylquinic acid from the wild groundnut,Arachis paraguariensis (Chod et Hassl.)

A novel compound, 1-caffeoyl-4-deoxyquinic acid (1-CdQA) has been identified along with 3-caffeoylquinic acid (3-CQA) and 5-caffeoylquinic acid (5-CQA) (syn. chlorogenic acid) in the foliage ofArachis paraguariensis, a wild species of groundnut that is highly resistant to attack by the larvae ofSpodoptera litura. When neonate larvae were fed on diets treated with 3-CQA or 1-CdQA, their development was severely inhibited compared to larvae on untreated diets, and the effects were similar in nature and magnitude to those observed for larvae feeding on diets treated with 5-CQA, rutin, and quercetin. The effects of all the compounds were dose related, and their optimal concentration was approximately 3 mM, which corresponds to the total foliar concentration of both caffeoylquinic acids and quercetin diglycosides inA. paraguariensis. After 24 h, the development of third stadium larvae feeding on diets treated with 5-CQA, rutin and 1-CdQA was promoted compared to larvae on control diets, but after 96 hr larvae feeding on treated diets had gained significantly less weight than those on the control diets. 1-CdQA, 3-CQA, and quercetin dyglycosides (previously identified in the foliage ofA. paraguariensis) are considered to be valuable components in resistance of groundnuts toS. litura and may provide useful genetic markers in future breeding for resistance to this pest.