Development of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) on pollen from Bt-transgenic and conventional maize

Abstract

Maize (Zea mays) pollen is highly nutritious and can be used by predatory arthropods to supplement or replace a carnivorous diet. We demonstrate that maize pollen can be utilized by larvae of the green lacewing, Chrysoperla carnea (Neuroptera: Chrysopidae) under laboratory conditions. Complete development on maize pollen was not possible, but 25% of neonates reached the third instar. When only one instar was fed with pollen and the other two instars with eggs of Ephestia kuehniella (Lepidoptera: Pyralidae), 58–87% of the larvae reached the pupal stage. The experiments included pollen produced by nine cultivars: three genetically modified (GM) cultivars expressing the Bacillus thuringiensis proteins Cry1Ab or Cry3Bb1, their corresponding non-transformed near-isolines, and three conventional cultivars. Maize cultivars were grown in two batches in a glasshouse. Their pollen differed by up to 59% in total protein content, 25% in C:N ratio, and 14% in grain diameter, but the differences were inconsistent and depended on the batch. Lacewing performance was not affected by maize cultivar. For environmental risk assessment of GM plants, in planta studies must consider the variability among conventional cultivars, individual plants, batches, and environmental conditions when evaluating the ecological significance of differences observed between GM and near-isolines.

Consumption of Bt Maize Pollen Containing Cry1Ie Does Not Negatively Affect Propylea japonica (Thunberg) (Coleoptera: Coccinellidae)

“…In our feeding experiment, the ladybirds were continually fed on Bt maize pollen for more than four weeks, while the pollen shedding period of maize normally lasts for 5–8 days with a maximum of 14 days [28,29]. In addition, our previous study had confirmed that P. japonica ingested much larger amounts of maize pollen under laboratory, confined conditions when compared to the field situation [30].…”

Dealing with food shortage: larval dispersal behaviour and survival on non‐prey food of the hoverfly Episyrphus balteatus

“…Similar effects of a non-prey diet were observed for ladybird and lacewing development. These larvae survived well on non-prey diets, but development was prolonged or not completed (Limburg & Rosenheim, 2001;Berkvens et al, 2008;Meissle et al, 2014). Interestingly, E. balteatus larval weight and survival did not differ between the different types of non-prey diet (honey, pollen, honey + pollen), indicating that none of the non-prey diets, whether protein-rich, sugar-rich or containing ample protein and sugar, was more suitable for larval survival than any of the others.…”

Assessment of unanticipated unintended effects of genetically modified plants on non‐target organisms: a controversy worthy of pursuit?

“…It has been stressed that data on plant-NTO interactions will not add weight of scientific evidence to the ERA due to confounding factors that may obscure the interpretation of the results Meissle et al 2014). If a NTO study using plant material as test substance reveals differences in NTO performance, then it can be challenging to separate transformation-related effects from genetic background/breeding-related effects, especially if an inappropriate comparator has been used as control (reviewed by Romeis et al 2011Romeis et al , 2013.…”

“…Ideally, the comparator should be grown under the same environmental/agricultural conditions as the GM plant (Romeis et al 2013). Meissle et al (2014) also indicated that the lack of baseline data may further complicate the interpretation of the results. However, EFSA considers that the natural variation estimated from a set of reference varieties grown under the same conditions could help to put observed differences between the GM plant and its comparator into context, and thus to evaluate their biological relevance in terms of NTO performance (Goedhart et al 2014).…”

“…Therefore, the ERA guidelines require the assessment of potential hazards that unintended changes may pose to NTOs, in addition to the intended ones (EFSA 2010a). However, the types of evidence and efforts necessary to inform the assessment of adverse effects on NTOs arising from unintended changes in GM plants for cultivation remain a contentious issue of debate in the EU (Garcia-Alonso 2010; Herman and Raybould 2013;Meissle et al 2014;Ladics et al 2015).…”