A pheromone is a chemical that an animal or an insect produces with the aim of changing the behavior of another of the same species. In honey bee, the brood is entirely dependent on the protection accorded by the bee nurses. The absence of workers and more so nurse care result in brood diminish. Thus, larval needs for food or warmth, as well as their age, need to be recognized by nurses, while the workers have to allocate energy to fulfill these requirements.
Brood recognition pheromone is produced by both larvae and pupae. The pheromone is a complex mixture of compounds that act both as primer and releaser hormone. The brood pheromone is a blend of 10 fatty-acid esters. These components also modulate adult caste ratios and foraging ontogeny dependent on its concentration. The distribution of the constituents changes with the larva’s age, the degree of hunger, and needs. Brood Pheromone from young larvae screams for them to be fed while from pupae it begs for workers to cap them over.
The primary function of brood pheromone is to prevent worker bees from bearing offspring in a bee community that has developing young bees. Brood recognition pheromone inhibits ovarian development in workers and assists nurse bees differentiate worker larvae from drone larvae and pupae.
Brood pheromone is secreted by larval salivary glands, besides secretion of silk which is necessary for developing pupal cocoon. The composition of the pheromone produced varies by the larval age and the function of the caste. The brood pheromone treatment increases the brood area and augments the number of bees as well as the larger amount of extractable protein from hypopharyngeal glands thus indicating an improved nutritional environment.
Besides the effects on larval development, Brood pheromone causes an expansion in bee community augmentation also through a regulation of worker bee behavioral development. The treatment of colonies with brood pheromone caused an increased number of pollen foragers and augmented the weight of pollen load they transport. Furthermore, pollen intake is adjusted by brood pheromone by modifying the proportion of pollen to no pollen foragers. Treatment with brood pheromone remarkably decreased pollen forager reversal time in the hive, adjusting the ratio of pollen to non-pollen foragers entering the colony.
Through brood recognition pheromone, young larvae can allocate priority to the duty of foraging by workers to increase food stores for their growth. Hence, in the complication of honey bee chemical conveyance, E-β-ocimene, a pheromone of young larvae, gives the brood the means to convey their nutritional needs to the workers.