Effects of synthetic juvenile hormone and a juvenile hormone analogue, methyl farnesoate dihydrochloride, on pupal development of the yellow mealworm Tenebrio molitor L.

Abstract

The result of treating Tenebrio molitor L. pupae with synthetic juvenile hormone (JH) or a juvenile hormone analogue, methyl farnesoate dihydrochloride (DMF), is to arrest pupal development, producing pupal/adult intermediates. Both substances induced approximately 50% pupal/adult intermediates at a topically applied dose of 1 μg. The activity was greatly affected by the age of the pupa at the time of treatment, one- and two-day-old pupae being the most sensitive. Applied to four-day-old and older pupae complete metamorphosis to the adult was possible at a dose of 8 μg of synthetic JH and up to 200 μg for DMF. Doses above these levels merely increased toxicity without juvenilising activity.