The rice planthopper parasitoid Anagrus nilaparvatae is not at risk when feeding on honeydew derived from Bt rice

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 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 rice and Cry2A rice on different life-table parameters and parasitism dynamics of the egg parasitoid Anagrus nilaparvatae were evaluated under laboratory and field condition. Furthermore, the Bt levels and the sugar and amino acid composition of honeydew were analyzed. 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 rice 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 were not significantly altered for the tested Bt rice lines compared to the parental non-Bt plant. The quality of honeydew derived from the tested Bt rice lines as a food resource for natural enemies was maintained.