Table 2.

Queen/worker production in A. mellifera.

	Signal	Source	Target	Role
First-order signals	Internal developmental constraints of larvae	Internal to each larva	Internal to each larva	Internally controls the development of larvae
Second-order signals	Queen cells	Nest workers	Queen-larvae	Larger comb cell volume allows for the increased growth of queen-larvae
	Worker cells	Nest workers	Worker-larvae	Smaller comb cell restricts growth of worker-larvae
	Royal jelly	Nurses	Queen-larvae	Induces the queen developmental program by causing an epigenetic change
	Brood food	Nurses	Worker-larvae	Induces the worker developmental program by not causing an epigenetic change