A Meta-Analysis of Effects of Bt Crops on Honey Bees (Hymenoptera: Apidae)

Abstract

BackgroundHoney bees (Apis mellifera L.) are the most important pollinators of many agricultural crops worldwide and are a key test species used in the tiered safety assessment of genetically engineered insect-resistant crops. There is concern that widespread planting of these transgenic crops could harm honey bee populations.Methodology/Principal FindingsWe conducted a meta-analysis of 25 studies that independently assessed potential effects of Bt Cry proteins on honey bee survival (or mortality). Our results show that Bt Cry proteins used in genetically modified crops commercialized for control of lepidopteran and coleopteran pests do not negatively affect the survival of either honey bee larvae or adults in laboratory settings.Conclusions/SignificanceAlthough the additional stresses that honey bees face in the field could, in principle, modify their susceptibility to Cry proteins or lead to indirect effects, our findings support safety assessments that have not detected any direct negative effects of Bt crops for this vital insect pollinator.

Honey Bees (Apis mellifera L.) and Pollination Issues: Current status, impacts and potential drivers of decline

“…The GMO crops with insecticidal properties could have a negative, sub-lethal, effect on bees. However, this concern of negative effect of GMOs have not been verified (Marvier, McCreedy, Regetz, & Kareiva, 2007;Duan, Marvier, Huesing, Dively, & Huang, 2008). The worker bees and colonies fed pollen from genetically modified Bacillus thuringiensis (Bt) corn did not have increased rates of mortality (Rose, Dively, & Pettis, 2007).…”

A review of the environmental safety of the Cry1Ac protein

“…Papers must meet the following criteria to be included in the database: (i) involve a field crop species that has been genetically transformed to express one or more cry genes derived from Bacillus thuringiensis; (ii) measure effects of the transformed crop for compiling this information has been created to facilitate continuing study (Duan et al, 2008(Duan et al, , 2010Marvier et al, 2007;Naranjo, 2009;Wolfenbarger et al, 2008). When GE plants that express Cry proteins, including Cry1Ac cotton, were compared to control plants that were not treated with chemical insecticide there was a reduction in arthropod abundance, but when control plants are treated with insecticide arthropod abundance is significantly higher in GE plants expressing Cry proteins (Marvier et al, 2007;Naranjo, 2009Wolfenbarger et al, 2008.…”

Effects of multiple Bt proteins and GNA lectin on in vitro-reared honey bee larvae

“…Bt crops expressing single Cry proteins were not found to impact honey bees during a recent meta-analysis (Duan et al, 2008). However, no studies assessing the risk of simultaneously expressed Cry proteins on honey bees have been conducted until now.…”

“…By feeding on pollen and nectar, honey bees can be exposed to insecticidal proteins expressed by genetically modified (GM) crops (Duan et al, 2008;Romeis et al, 2008;Malone and Burgess 2009). Transgenic gene products expressed in insect-resistant GM crops can confer protection against specific herbivorous pest insects.…”