Sex pheromone production and reproductive behaviour in gamma-irradiated Tenebrio molitor.

Studies to determine the effects of gamma-radiation on sex pheromone production in female Tenebtio molitor showed that irradiation of females either as newly emerged or as pharate adults with 3.5 or 7 krad had no significant effect on their sex pheromone activity when compared to that of normals. However, treatment of irradiated insects with a juvenile hormone analogue increased their pheromone activity, whereas it decreased the pheromone activity in the normals. Ovary maturation was inhibited in irradiated insects, and it could not be alleviated by treatment with juvenile hormone analogue. Since ovarian transplants from normal to irradiated insects showed yolk deposition, whereas reciprocal transplants did not, it is concluded that the inhibition in yolk deposition in the ovaries of irradiated insects was due to radiation damage to the ovary itself rather than to the neuroendocrine system. Irradiation of the males with 7 krad did not affect their ability to respond to the female sex pheromone or their sexual vigour. At higher doses their response was slow and it decreased with increase in radiation dose, and also as a function of time after irradiation.