Amino acids in honeybee worker haemolymph

In honeybee workers proline was the predominant amino acid and comprised from 50% in newly emerged bees up to 80% of total amino acids from the 3(rd) day on. The overall concentration averaged at about 20mM in newly emerging bees, rose to a maximum of about 25mM at the 3(rd)-5(th) day and decreased in older bees. Essential amino acids decreased by 40% during the first 3 days and thereafter stayed constant. The bulk of amino acids with a lower concentration (from traces to about 2mM) showed either no change in concentration or was higher in newly emerging bees and decreased during the lifespan of the insects. Forager bees, collected after flight, had significantly lower proline concentrations as compared to 22 day old bees collected from the colony, while the concentrations of the bulk of all other amino acids did not change significantly. There was a great variance in the concentration of all amino acids between different colonies but we could not prove dependency on relatedness.