Added vegetable and fish oils to low-fat pollen diets: effect on honey bee (Apis mellifera L.)consumption
- Australian Journal of Entomology, 49(2), p.182-189, 2010 .
Little is known about which commercial oils could be used as an ingredient in improving artificial feedstuffs for honey bees. To test whether the oils are palatable or whether honey bees showed a preference, they were added to a low-fat pollen known to be attractive to bees. Oils were added at 2 percent above the known oil content of the pollen to a level about half that of a range of melliferous plants. Of 27 different plant and fish-based oils, only linseed and coconut oil-enhanced pollen diets were consumed by bees at a significantly greater rate (P?0.05)than pollen itself. Other oils added to pollen that had higher but not significantly different consumption rates by bees to pollen in palatability tests were (highest to lowest): evening primrose, almond, grape seed, apricot, olive, blended vegetable, orange essential oil (EO), linoleic acid, soyabean, avocado, mustard seed, cod liver, sesame and canola. Other oils found unpalatable and discarded from further testing were: gingelly, castor, peanut, rose EO, oleic acid, fish, sunflower, macadamia, rice bran, clary sage EO and lavender EO. At 2 percent, two of the four essential oils tested were found to be significantly unpalatable and not preferred by bees. The concentration of lavender and clary sage in a pollen diet was perhaps too high. Using alcohol via the addition of 2 percent rum to enhance volatiles from the pollen diet effectively increased consumption of pollen diets by honey bees. Using both palatability and preference testing methodologies to determine the attractiveness of diets to bees gave the same result. Either test will give the researcher a way of determining the food value of ingredients in diets or full diets.