> I remember seeing data indicating that too much protein can be toxic to bees;

A lot of research on this topic has been done with ants:

It remains unclear how high-protein / low-carbohydrate
diets shorten lifespan in ants. Arganda & al. (2017) started 
to answer this question in a recent study.

They showed that high-protein diets shorten lifespan in
Argentine ants Linepithema humile, because the final
products of the protein digestion i.e., the amino acids
are harmful, especially: methionine, serine, threonine
and phenylalanine. They showed that these amino acids
shortened lifespan even more than crude proteins. 

The hypothesis is that an excess in amino acids increases
potentially toxic nitrogen waste products (Wright 1995)
and over-stimulates nutrient-sensing pathways that regulate
lifespan such as the TOR pathway, a genetic pathway
functionally conserved throughout evolution (Pankaj &
Brian 2004, Simpson & Raubenheimer 2009).

Nevertheless, if an excess of protein decreases individuals’
lifespan, it can increase the reproduction and
the growth of the colony. For instance, when Camponotus
floridanus colonies are fed with a surplus protein the egg
production by queens increases (Nonacs 1991). 

Some studies have also shown that colonies supplemented 
with protein produced more sexuals (male and / or female),
more larvae and larger individuals (Backus & Herbers
1992, Aron & al. 2001). A recent study (Bernadou & al.
2018) unveiled that reproductive division of labour is also
influenced by food quality.

Enikö Csata, Audrey Dussutour. Nutrient regulation in ants (Hymenoptera: Formicidae): a review.
Myrmecological News, The Austrian Society of Entomofaunistics (ÖGEF), 2019, 29, pp.111-124. 

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