Adult (2–20 hr old) viviparous Aphis craccivora were treated with 0.5 to 4.0 μg of precocene II. Treatment led to dose-related reduction in the progeny number, survival and life span of the aphid, but wing development was not affected. With 2.0 μg/aphid or more of precocene II, all surviving offsprings shared precocious metamorphosis, but even with 0.5 μg/aphid, about 20% progeny showed such metamorphosis with 1.0 and 1.5 μg/aphid. Early nymphs tend to undergo precocious metamorphosis earlier, in the second moult.

Males of the Triatominae, Panstrongylus megistus and Triatoma infestons, show a considerable difference concerning the time necessary for them to acquire the capacity for the first mating. P. megistus copulates from the eighth day of adult life, irrespective of whether or not it has been fed, while T. infestons copulates about 17 days after the imaginai moult and only after a blood-meal. These differences might be due to the secretory activity of T. infestons male accessory glands whose full development is reached only after two saturant blood-meals. If allatectomy is performed in male P. megistus soon after the imaginai moult, accumulation of secretion does not occur in 3 of the 4 accessory glands. Topical application of precocene II (200 μg/insect)a few days before or soon after the imaginai moult in P. megistus, halves the amount of secretion in the accessory glands.