RESUMEN
BACKGROUND: Honeydew is a sugar-rich excretion produced by sap-feeding Sternorrhyncha and is an important source of carbohydrates for natural enemies, especially for parasitoids. Honeydew derived from genetically modified (GM) crops can contain amounts of the transgene product. Thus, it is a possible route of exposure for natural enemies feeding on honeydew. In the present study, the potential effects of Nilaparvata lugens honeydew derived from Cry1C and Cry2A rice on different life-table parameters and parasitism dynamics of the egg parasitoid Anagrus nilaparvatae were evaluated under laboratory and field conditions. Furthermore, the Bacillus thuringiensis (Bt) levels and the sugar and amino acid composition of honeydew were analyzed. RESULTS: Results indicated that A. nilaparvatae was exposed to Bt proteins by feeding on N. lugens honeydew produced from Bt rice. However, honeydew derived from the tested Cry1C and Cry2A rice lines did not affect the development, longevity, emergence rate and fecundity of A. nilaparvatae. Also, the parasitism dynamics in the field remained unaffected. In addition, the sugar and amino acid composition of N. lugens honeydew was not significantly altered for the tested Bt rice lines compared with the parental non-Bt plant. CONCLUSION: The quality of honeydew derived from the tested Bt rice lines as a food resource for natural enemies was maintained. © 2018 Society of Chemical Industry.
Asunto(s)
Proteínas Bacterianas/efectos adversos , Endotoxinas/efectos adversos , Hemípteros/parasitología , Proteínas Hemolisinas/efectos adversos , Interacciones Huésped-Parásitos , Insecticidas/efectos adversos , Oryza/química , Avispas/fisiología , Aminoácidos/química , Animales , Toxinas de Bacillus thuringiensis , Dieta , Tablas de Vida , Plantas Modificadas Genéticamente/química , Azúcares/químicaRESUMEN
Most parasitoids depend on carbohydrate-rich foods to maximize their longevity and reproduction potential. These food resources are commonly from floral nectar, extra-floral nectar, and honeydew, which contain monosaccharides, disaccharides, and oligosaccharides. Here, we report an experiment to explore the effects of 12 naturally occurring sugars on the gustatory response, longevity, and fecundity of Trichogramma japonicum and Trichogramma chilonis These two parasitoid species differed in their responses to the tested sugars. Trichogramma japonicum showed a high gustatory response to eight sugars, but T. chilonis to only six. However, only fructose, glucose, and sucrose increased the longevity of T. japonicum, and only glucose enhanced the fecundity. For T. chilonis, fructose, galactose, gluctose, maltose, melibiose, sucrose, and melezitose prolonged the longevity and increased fecundity. Furthermore, female T. japonicum benefitted much less from the ingestion of sugars when compared with female T. chilonis For T. japonicum, feeding on suitable sugars, longevity was increased by a factor of 1.8-2.0, and fecundity by a factor of 1.5. In T. chilonis, longevity increased by a factor of 2.9-5.2 and fecundity by 2.7-4.0. Thus, providing the right sugars to the parasitoids will help to enhance the biological control efficacy of Trichogramma, and T. chilonis in particular.