Abstract – We evaluated the microalga Arthrospira platensis (commonly called spirulina), as a pollen substitute for honey bees. Nutritional analyses indicated that spirulina is rich in essential amino acids and a wide variety of functional lipids (i.e., phospholipids, polyunsaturated fatty acids, and sterols) common in pollen. Feeding bioassays were used to compare dry and fresh laboratory-grown spirulina with bee-collected pollen and a commercial pollen substitute using sucrose syrup as a control. Diets were fed ad libitum as a paste to newly emerged bees in cages (10–13 cage replicates) and bees were sampled at days 5 and 10 for physiological andmolecularmeasurements. Spirulina diets produced biomarker profiles (thorax weight, head protein content, and beneficial gut bacteria abundance) that
were indicative of elevated nutritional states, meeting or exceeding the other diets in some metrics despite reduced consumption. Furthermore, spirulina diets led to significantly increased fat body lipid content and mRNA levels of the central storage lipoprotein vitellogenin.We conclude that spirulina has significant potential as a pollen substitute or prebiotic diet additive to improve honey bee health.

Spirulina beefeed.pdf (1.79 mb)