Accumulation and variability of maize pollen deposition on leaves of European Lepidoptera host plants and relation to release rates and deposition determined by standardised technical sampling

Abstract

BackgroundRisk assessment for GMOs such as Bt maize requires detailed data concerning pollen deposition onto non-target host-plant leaves. A field study of pollen on lepidopteran host-plant leaves was therefore undertaken in 2009–2012 in Germany. During the maize flowering period, we used in situ microscopy at a spatial resolution adequate to monitor the feeding behaviour of butterfly larvae. The plant-specific pollen deposition data were supplemented with standardised measurements of pollen release rates and deposition obtained by volumetric pollen monitors and passive samplers.ResultsIn 2010, we made 5377 measurements of maize pollen deposited onto leaves of maize, nettle, goosefoot, sorrel and blackberry. Overall mean leaf deposition during the flowering period ranged from 54 to 478 n/cm2 (grains/cm2) depending on plant species and site, while daily mean leaf deposition values were as high as 2710 n/cm2. Maximum single leaf-deposition values reached up to 103,000 n/cm2, with a 95 % confidence-limit upper boundary of 11,716 n/cm2.ConclusionsDaily means and variation of single values uncovered by our detailed measurements are considerably higher than previously assumed. The recorded levels are more than a single degree of magnitude larger than actual EU expert risk assessment assumptions. Because variation and total aggregation of deposited pollen on leaves have been previously underestimated, lepidopteran larvae have actually been subjected to higher and more variable exposure. Higher risks to these organisms must consequently be assumed. Our results imply that risk assessments related to the effects of Bt maize exposure under both realistic cultivation conditions and worst-case scenarios must be revised. Under common cultivation conditions, isolation buffer distances in the kilometre range are recommended rather than the 20–30 m distance defined by the EFSA.Electronic supplementary materialThe online version of this article (doi:10.1186/s12302-016-0082-9) contains supplementary material, which is available to authorized users.

Annual post‐market environmental monitoring (PMEM) report on the cultivation of genetically modified maize MON 810 in 2015 from Monsanto Europe S.A.

“…Five publications were relevant for the food and feed (FF) safety assessment (in terms of toxicity and allergenicity), 13 publications pertained to the ERA or the IRM of maize MON 810 (most studies assessed the interaction of maize MON 810 with target organisms and non-target organisms). Three of the 18 publications, B € ottger et al (2015), Holderbaum et al (2015) and Xu et al (2015), have already been assessed by EFSA (EFSA, 2016b) or the GMO Panel (EFSA GMO Panel, 2016), and have concluded that no environmental safety concerns owing to maize MON 810 and Cry1Ab were identified.…”

“…(1) existing food and food ingredients produced from genetically modified insect resistant maize MON810; (2) feed consisting of and/or containing maize MON810, including the use of seed for cultivation; and of (3) (Hofmann et al, 2016) for previous environmental risk assessment conclusions and risk management recommendations on the cultivation of Bt-maize events MON810, Bt11 and 1507. EFSA supporting publication 2016;13 (7) …”

“…Annex VII was supplemented by notes providing guidance on the objectives, general principles and design of the monitoring plan. GMO Panel, 2011a, 2012a, 2013, 2014a, 2015a,b, 2016 Following the request by the consent holder for the renewed market authorisation of maize MON 810, the GMO Panel adopted a scientific opinion on the renewal applications submitted under Regulation (EC) No 1829/2003 for: existing food and food ingredients produced from maize MON 810; feed consisting of and/or containing maize MON 810, including the use of seed for cultivation; and food and feed additives, and feed materials produced from maize MON 810 (EFSA, 2009). The GMO Panel concluded that maize MON 810 is as safe as its conventional counterpart with respect to potential effects on human and animal health, and that maize MON 810 is unlikely to have any adverse effect on the environment in the context of its intended uses, especially if appropriate management measures are put in place in order to mitigate possible exposure of non-target (NT) Lepidoptera.…”

“…6 In two 2016 Technical Reports (EFSA, 2016a,b), following the requests of the European Commission, 7,8 EFSA assessed the implications of new relevant scientific publications by Bøhn et al (2016) and Hofmann et al (2016) On 13 October 2016, the European Commission requested the GMO Panel to assess the 2015 PMEM report and, in particular, to evaluate the findings of the monitoring activities, taking into consideration the comments received from Member States and to assess the appropriateness of the methodology if this is found to differ compared to the previous season.…”

Spatial analysis of the occurrence of protected butterflies in six European biogeographic regions as a tool for the environmental risk assessment of Bt maize

“…EFSA , 2015. However, scientific controversies remain on the isolation distances and buffer zones necessary to protect these species (Hofmann et al 2016, Lang et al 2015.…”