Effects of ingestion of a Bacillus thuringiensis toxin and a trypsin inhibitor on honey bee flight activity and longevity

To assess potential impacts of transgenic pest-resistant plants, newly-emer ged adult honey bees from ten colonies were tagged, placed in cages at 33 d egreesC, and fed with 625 mug/g Cry1Ba Bacillus thuringiensis (Bt) toxin or 2.5 mg/g aprotinin proteinase inhibitor in pollen-food (equivalent to 0.25 % or 1% of total soluble protein). Control bees were given similar food wit hout additive. All foods were consumed at similar rates. After seven days, all bees were returned to their hives. Subsequent observations showed that Cry1Ba-fed bees did not differ significantly from control bees in the timin g of their first flight, the period during which flights took place or in e stimated longevity. However, aprotinin-fed bees began to fly and also died about three days sooner than Cry1Ba-fed or control bees. Their flight perio ds were similar to those of the other bees. The effects of transgenic aprot inin-plants on honey bees will thus depend on gene expression levels in pol len.