Ability of the Oriental Fruit Moth Grapholita molesta (Lepidoptera: Tortricidae) to Detoxify Juglone, the Main Secondary Metabolite of the Non-host Plant Walnut

• Published in: Journal of chemical ecology 2011-10, Vol.37 (10), p.1110-1116
• Main Authors: Piskorski, Rafal, Ineichen, Simon, Dorn, Silvia
• Format: Article
• Language: English
• Subjects: Agriculture; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Applied ecology; Artificial diets; Biochemistry; Biological and medical sciences; Biological Microscopy; Biomedical and Life Sciences; Butterflies & moths; Chemical analysis; Cydia pomonella; Ecology; Ecotoxicology, biological effects of pollution; Entomology; Flowers & plants; Fruit - parasitology; Fruit trees; Fruits; Fundamental and applied biological sciences. Psychology; General aspects; Growing season; Herbivory; Host-Parasite Interactions; Insecta; Insects; Invasive plants; Invasive species; Invertebrates; Juglans - metabolism; Larvae; Life Sciences; Metabolites; Moths - physiology; Naphthoquinones - metabolism; Plant species; Rosaceae - parasitology; Secondary metabolites
• ISSN: 0098-0331; 1573-1561
• DOI: 10.1007/s10886-011-0015-4

Many plant species produce toxic secondary metabolites that limit attacks by herbivorous insects, and may thereby constrain insect expansion to new hosts. Walnut is a host for the codling moth Cydia pomonella , which efficiently detoxifies the main walnut defensive compound juglone (5-hydroxy-1,4-naphthoquinone). The oriental fruit moth Grapholita molesta, which also belongs to the tribe Grapholitini, does not feed on walnut. We tested the performance of G. molesta, a highly invasive species, on artificial diets containing juglone at levels mimicking those found in walnut over the growing season. Juglone-fed G. molesta survived relatively well to adulthood, but larval and adult body weights were reduced, and larval developmental time was prolonged in a dose-dependent fashion. Chemical analysis of frass from larvae that had been fed a juglone-containing diet suggests that G. molesta reduces juglone to non-toxic 1,4,5-trihydroxynaphthalene in its gut. This unexpected tolerance of G. molesta to high levels of juglone may facilitate expansion of the host range beyond the current rosacean fruit trees used by this invasive pest.