Transgenic corn decreased total and key storage and lipid transport protein levels in honey bee hemolymph while seed treatment with imidacloprid reduced lipophorin levels

Abstract

Pollen substitutes are currently widely used in apiculture because of a lack of natural forage and an increasing need for bees for pollination services. A major concern in the confection of bee diets is whether specific ingredients, such as GMO grain, or contaminants such as pesticides that are applied to crops, negatively impact bee health. We measured hemolymph protein levels and the lifespan of honey bees fed on diets containing non-hybrid (IAC-Airan), hybrid (AG 7088) or transgenic (AG 8088YG) maize, the seeds of which had been treated with fipronil, imidacloprid or left untreated. Corn from these plantings was harvested, dried and finely ground, and then used for the preparation of corn-based diets. Groups of 100 newly emerged bees were placed in cages, where the diets were offered ad libitum. Honey bee lifespan was similar for all the corn diets, though shorter than for bees fed beebread and longer than for bees fed only honey. Total protein in the hemolymph of bees fed with transgenic maize was 15% lower than in bees fed on non-hybrid maize; lipophorin and vitellogenin, were more reduced, by over 30%. Irrespective of corn variety, imidacloprid resulted in over 25% lower levels of lipophorin compared with the control. Lower storage and transport protein levels would compromise the ability of the bees to rear brood and develop an adequate immune response to pathogen challenge. Consequently, transgenic maize, as well as any maize produced from seed treated with imidacloprid should not be included as ingredients in honey bee diets. Maíz transgé nico disminuí niveles de proteínas claves de almacenamiento y transporte de lípidos en hemolinfa de abejas melíferas así como el tratamiento de semillas con imidacloprid reduce los niveles de lipoforina Substitutos del polen actualmente son utilizados en larga escala en la apicultura por causa de la falta de alimento natural y un aumento en la necesidad de abejas para servicios de polinizació n. Una preocupació n importante en la confecció n de dietas para las abejas es si ingredientes específicos, como granos OGM, o contaminantes como plaguicidas aplicados a los cultivos, impactan negativamente sobre la salud de la abeja. Nosotros medimos los niveles de proteína en la hemolinfa y el tiempo de vida de abejas melíferas alimentadas con dietas conteniendo maíz no-hibrido (IAC-Airan), híbrido (AG 7088) o transgénico (AG 8088YG); durante la siembra de estos cultivos las semillas fueran tratadas con fipronil, imidacloprid o sin ningún tratamiento. Muestra de maíz de estas plantaciones fueran cosechadas, secadas, molidas y después utilizadas para preparar las dietas basadas en maíz. Grupos de 100 abejas recién emergidas fueran colocadas en jaulas y las dietas fueran ofrecidas a libre consumo. El tiempo de vida de las abejas fue similar para todas las dietas con maíz, pero más corto del que para abejas alimentadas con pan de la abeja y mayor en comparació n con abejas alimentadas solamente con miel. Los niveles de proteína total en la hemolinfa de las abejas alimentadas con maí...

Imidacloprid-induced oxidative stress in honey bees and the antioxidant action of caffeine

“…Despite this lethal effect, other sublethal effects may manifest in bees exposed to imidacloprid, several of them already described in scientific papers (Blacquière et al 2012). In addition, considering the effect on the energy metabolism, Nicodemo et al (2014) demonstrated that imidacloprid affects energy production by bees' mitochondria and Nicodemo et al (2018) showed that imidacloprid reduces lipophorin levels in honey bee hemolymph, but the effects of this insecticide on the cellular antioxidant system of these insects have not yet been described.…”

Effect of Protein Supplementation in the Bee Apis mellifera L. Exposed to the Agrochemical Fipronil

“…Protein supplementation of bee swarms did not interfere with the protein content of the hemolymph of the bees, although a direct relationship between these two parameters may occur (De Jong et al, 2009). Nicodemo et al (2018) verified an increase in hemolymph protein content in bees at seven days of age who had received protein supplementation under laboratory conditions. In the present experiment with protein, supplementation was conducted in field conditions, whith bees performing their normal foraging activities and using the protein provided to balance their needs, which did not promote an increase in the protein content of the hemolymph.…”

Risks and opportunities associated with pollinators’ conservation and management of pollination services in Latin America

“…Genetically modified crops are herbicide tolerant (HT) or insect resistant (IR), and they can pose a threat to pollinators by having lethal or sub-lethal effects on adult insects or larvae (Nicodemo et al 2018). A recent review on honeybees showed no clear negative effects of GMO on colony development (Ricroch et al 2018).…”

“…A recent review on honeybees showed no clear negative effects of GMO on colony development (Ricroch et al 2018). Supplements (i.e., nectar and pollen substitutes) containing GMO are used in apiculture to feed honeybees when flowers are scarce, and recent experimental studies have shown negative effects on bee health following the addition of a supplementary diet (for example, processed GMO corn) (Nicodemo et al 2018). Moreover, bees visit GMO soybean flowers, and their pollen can be found in honey harvested by beekeepers (Villanueva-Gutiérrez et al 2014).…”