Morphometry and biological parameters of different instars of the giant brown peach aphid: Pterochloroides persicae Cholodkovsky 1899 (Hemiptera: Aphididae) in Tunisia

Summary. Individuals of Pterochloroides persicae reared under controlled conditions were used to describe the morphometry and biological parameters of instars of this aphid. Our results showed that P. persicae developed four instars before reaching the adult stage. The first and the second larval instars both have five antennal segments, although the others have six segments. A significant difference was observed between instars in the first antennal segment (F = 56.11; df = 4, P = 0.026), in the body length (F = 115.38; df = 4, p = 0.014) and in the cauda length (F = 72, 77; df = 4, p = 0.021). The study of developmental and reproductive performance of P. persicae showed that the first instar lasted for 3.17 days, the second instar 2.35 days, the third instar 4.68 days, the fourth instar 5.035 days and the adult 6.86 days. We demonstrate also that the generation time lasted for 15.26 days. The life span was 22.11 days. As for fecundity, a single female of P. persicae gave birth to 29.68 ± 7.38 nymphs with an average reproductive rate per day of 4.32 ± 2.16.