gene mfe expression and juvenile hormone, JH, titers in the life cycle of the highly eusocial stingless bee, hemolymph JH titers for all life cycle stages of Melipona scutellaris queens and workers, overview. The JH titer is high in the second larval instar, drops in the third, and rises again as the larvae enter metamorphosis. During the pupal stage, mfe expression is initialy elevated, but then gradually drops to low levels before adult emergence. No variation is seen in the JH titer. In adult virgin queens, mfe expression and the JH titer are significantly elevated, possibly associated with their reproductive potential. For workers, JH titers are lower in foragers than in nurse bees, while mfe expression does not differ