Honey bee foraging preferences, effects of sugars, and fruit fly toxic bait components.

Field tests were carried out to evaluate the repellency of the Dow AgroSciences fruit fly toxic bait GF-120 (NF Naturalyte) to domestic honey bees (Apis mellifera L.). GF-120 is an organically registered attractive bait for tephritid fruit flies composed of spinosad, hydrolyzed protein (Solulys), high-fructose corn syrup (ADM CornSweet 42 high-fructose corn syrup, referred to as invertose sugar or invertose here), vegetable oils, adjuvants, humectants, and attractants. Tests were carried out with non-Africanized honey bees in February and March 2005 and 2007 during periods of maximum hunger for these bees. In all tests, bees were first trained to forage from plates of 30% honey-water (2005) or 30% invertose (2007). In 2005 bees were offered choices between honey-water and various bait components, including the complete toxic bait. In 2007, similar tests were performed except bees were attracted with 30% invertose then offered the bait components or complete bait as no-choice tests. Initially, the 2005 tests used all the components of GF-120 except the spinosad as the test bait. After we were convinced that bees would not collect or be contaminated by the bait, we tested the complete GF-120. Behavior of the bees indicated that during initial attraction and after switching the baits, the bait components and the complete bait were repellent to honey bees, but the honey-water remained attractive. Invertose was shown to be less attractive to bees, addition of Solulys eliminated almost all bee activity, and addition of ammonium acetate completely eliminated feeding in both choice and no-choice tests. These results confirm previous tests showing that bees do not feed on GF-120 and also show that honey bees are repelled by the fruit fly attractant components of the bait in field tests.