Comparable performance of commercial honey bee (Hymenoptera: Apidae) colonies under alternative fall feeding...

Beekeepers use supplemental diets to support colonies when natural forage is scarce. Fall feeding is commonly used to bolster colony health, prepare them for winter, and ensure strong colonies for the spring. Unfortunately, any benefit that fall feeding offers comes only after substantial investments in feed and winter storage. Although many studies have examined the nutritional value of supplements, these questions have rarely been tested under commercial beekeeping conditions or in the context of fall feeding. We tested 2 hypotheses: (1) supplement‑fed colonies are as large and profitable as colonies fed natural pollen, and (2) colonies fed natural pollen or supplements are as large and profitable as unfed colonies. Across 2 years, we evaluated ∼700 colonies in 2 North Dakota apiaries. Colonies were fed the following in the fall (August-September) and before cold storage: 1 of 5 commercially available diets, a natural‑pollen positive control, or (in trial 2) no diet. Colony size was measured at 4 time points from pre‑feed to post‑almond pollination. Profitability was defined as the likelihood that colonies graded adequately for almond pollination or could be split after bloom. After accounting for fall apiary location and pre‑feed colony size, colonies fed Global 4% and AP23 were consistently as large and profitable as those fed natural pollen. In trial 2, unfed colonies performed as well as colonies fed pollen or supplements. Although outcomes were similar for colonies fed certain and natural pollen, the results of trial 2 indicate that fall feeding may not always be necessary.