Effects of ingestion of a biotin-binding protein on adult and larval honey bees

Abstract

-The insecticidal properties of biotin-binding proteins (BBPs) have recently been exploited in transgenic plants. As BBPs have a broad spectrum of insect toxicity, their potential impacts on non-target insects such as honey bees need to be assessed. In this study, the effects of feeding a purified BBP, avidin, to honey bee larvae and adults were determined. A realistic larval dosing regime was developed by estimating the pollen content of brood food in the field and adding avidin to artificial diet at rates that simulated the presence of avidin-expressing transgenic pollen in brood food. Larval survival and development were unaffected by avidin in assays which simulated larvae receiving pollen expressing 0, 4 or 40 µM avidin at concentrations of 164 µg pollen per mg food for the first 2 days and 880 µg pollen per mg food thereafter. Food consumption and survival of adult bees were also unaffected by avidin added to pollen-candy at levels corresponding to pollen expression of 0, 6.7 or 20 µM avidin.Apis mellifera / biotin-binding protein / avidin / transgenic plant

Development of hypopharyngeal glands in adult honey bees fed with a Bt toxin, a biotin-binding protein and a protease inhibitor

“…Measurements of acinus diameter, gland mass and protein content of the glands suggested that aprotinin, avidin and Cry1Ba, if present in transgenic pollen at the concentrations tested here, are extremely unlikely to have a marked effect on hypopharyngeal gland development. For the biotin-binding protein and the Bt toxin, this is in accord with earlier reports of no impacts on bees (Sims, 1995;Arpaia, 1996;Malone et al, 1999Malone et al, , 2002b.…”

Modes of honeybees exposure to systemic insecticides: estimated amounts of contaminated pollen and nectar consumed by different categories of bees

“…Some new tests have been proposed to estimate the larvae exposure. Among them, field (Oomen et al, 1992) and semi-field (Leyman et al, 1999;Tornier, 1999) tests do not appear appropriate since larval exposure cannot be controlled, whereas laboratory tests (Malone et al, 2002;Brødsgaard et al, 2003) might be used to estimate adequately the larvae exposure.…”

“…The amount of imidacloprid consumed by honeybees is determined by the following equivalence: 1 mg of sugar contained in nectar or honey = 4.75 pg of imidacloprid and 1 mg of pollen = 3.4 pg of imidacloprid in nectar and pollen coming from Gaucho ® seed-dressed plants. N Larvae consume royal jelly, produced by nurses, which contains honey and pollen (Haydak, 1943(Haydak, , 1968(Haydak, , 1970Kunert and Crailsheim, 1988;Malone et al, 2002).…”

Environmental risk assessment of transgene products using honey bee (Apis mellifera) larvae

“…However, as proteinase inhibitors are known to be extremely stable (as with pancreatic trypsin inhibitors found in mammals), is possible that PIs will be passed to the larvae with the larval jelly. However, if GM products only reach the larval food through modified pollen, the average amount of GM product in larval food in bee colonies would be between 0.1% and 0.2% if the pollen express 1% PI of total protein (calculation based on Wille et al, 1985 andMalone et al, 2002). Therefore, we chose 0.1% and 1.0% SBTI of total soluble protein as realistic low and high expression levels, respectively , and investigated the juvenile development, mortality, and adult body mass with larval diets containing 0.1% or 1.0% (w:w) SBTI of total protein.…”