Response of male corpora allata to ovarian stimulation in the cockroach, Diploptera punctata.

In Diploptera punctata, female corpora allata (CA) show a cycle of juvenile hormone (JH) synthesis in response to oocyte development. Whether the smaller male CA can also respond to the ovary was investigated. One or two pairs of male CA were implanted into allatectomized females during the period corresponding to egg growth. Low rates and no cycle of JH synthesis occurred in CA of sham-operated males or in male CA implanted into males or ovariectomized females. On the contrary, male CA, either one or two pairs, implanted into females with ovaries showed a cycle of increase and decrease in JH synthesis similar in pattern to that of female glands implanted into females. However, the peak of JH synthesis for a single pair of male CA occurred 1 day later than the peak for two pairs of male CA or one pair of female CA. Also the maximum rates of synthesis of one or two pairs of male CA were lower than those of female glands. However, rates of JH synthesis per cell and per unit volume of corpus allatum tissue were higher for one pair of male CA than for one pair of female CA. Thus, the intrinsic difference between male and female CA appears to be their size rather than rate of JH synthesis and ability to respond to ovarian stimuli.