Key points:

• Commercial pollen substitute patties were eaten by a portion of adult worker bees but weren't stored as bee bread or fed directly to larvae.
• Commercial pollen substitute patty consumption peaked in older workers, not the nurse bees.
• Open-fed, dry pollen substitute was collected by foragers and stored as bee bread.

Have you ever wondered where pollen substitutes go when they disappear from a hive or feeder?

A collection of studies from the University of Florida and Tocal College (AgriFutures Australia funded) have explored this question.

We dyed a variety of commercially available pollen substitutes without natural pollen and traced them through colonies in the field. This article summarises our findings.

Q: Where do pollen substitute patties go? 

A: Patties were consumed by a proportion of adult workers. They were neither stored as bee bread, nor fed directly to larvae ​(Noordyke et al., 2021)​.  

Dyed pollen substitute patties ended up in the guts of <50% of sampled adult workers across three diets. In contrast, the dye from fondant (pure sugar), ended up in most adult workers sampled from the colonies. This evidence caused us to ask another question… 

Q: Is there a specific age cohort of bees that consumes pollen substitute patties? 

A: Yes, pollen substitute patty use peaked in older workers aged 18-22 days old ​(Kleckner et al., 2026)​. 

You might think nurse bees (aged 0-11days) would be the primary users of pollen substitute patties because they eat the most pollen for brood rearing. If this were the case, pollen substitute use would likely peak around day 9-10 post-emergence when pollen consumption is naturally the highest ​(Crailsheim et al., 1992)​. Instead, we observed that pollen substitute patty consumption gradually increased as bees aged and peaked at resource handling age (pollen packers and foragers). We didn't test natural pollen patties or powder in this study which may be used by bees of different ages. 

Q: Do colonies use dry pollen substitutes from feeders outside the hive differently than patties provided inside the hive? 

A: Yes, dry powder pollen substitutes offered outside of hives were collected by foragers and stored in comb ​(Kratz, 2022)​. 

Foragers were observed collecting dyed dry pollen substitute from feeders, packing it onto their hindlegs, and bringing it back to their hives. The dry pollen substitute was then packed in the comb like bee bread. It's possible colonies stored the powder because it was foraged like natural pollen. 

A pollen substitute was dyed green to observe how bees use the substitute powder when provided in the open. Photo courtesy M. Kratz

Why does this matter to beekeepers? 

This research can improve diet development and inform our management decisions. The commercial pollen substitute patties tested in these studies did not get used like natural pollen. They may be beneficial when colonies face severe nutritional stress ​(Noordyke & Ellis, 2021)​, but they don't fully replace natural pollen.  

Colonies seem to use open-fed, dry pollen substitutes more like natural pollen than patties. However, one disadvantage is that colonies must compete for the open-fed powder which causes uneven uptake across an apiary, whereas patties or dry feed inside the hive can be delivered evenly or to the colonies that need feeding most. You might consider open feeding dry pollen substitutes if you want the feed to be stored for long-term use but remember that bees will prefer to collect pollen over substitute when available. 

Also consider nutritional quality, cost-benefit, and practicality of a pollen substitute before you invest. Although we still have many questions about supplementary feeding, these studies give us a few more answers about how to feed our bees.